Before moving tasks out of empty cpusets, update_tasks_nodemask()
is called, which calls do_migrate_pages(xx, from, to). Then those
tasks are moved to an ancestor, and do_migrate_pages() is called
again.
The first time: from = node_to_be_offlined, to = empty.
The second time: from = empty, to = ancestor's nodemask.
so looks like no pages will be migrated.
Fix this by:
- Don't call update_tasks_nodemask() on empty cpusets.
- Pass cs->old_mems_allowed to do_migrate_pages().
v4: added comment in cpuset_hotplug_update_tasks() and rephased comment
in cpuset_attach().
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Currently some cpuset behaviors are not friendly when cpuset is co-mounted
with other cgroup controllers.
Now with this patchset if cpuset is mounted with sane_behavior option,
it behaves differently:
- Tasks will be kept in empty cpusets when hotplug happens and take
masks of ancestors with non-empty cpus/mems, instead of being moved to
an ancestor.
- A task can be moved into an empty cpuset, and again it takes masks of
ancestors, so the user can drop a task into a newly created cgroup without
having to do anything for it.
As tasks can reside in empy cpusets, here're some rules:
- They can be moved to another cpuset, regardless it's empty or not.
- Though it takes masks from ancestors, it takes other configs from the
empty cpuset.
- If the ancestors' masks are changed, those tasks will also be updated
to take new masks.
v2: add documentation in include/linux/cgroup.h
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
To achieve this:
- We call update_tasks_cpumask/nodemask() for empty cpusets when
hotplug happens, instead of moving tasks out of them.
- When a cpuset's masks are changed by writing cpuset.cpus/mems,
we also update tasks in child cpusets which are empty.
v3:
- do propagation work in one place for both hotplug and unplug
v2:
- drop rcu_read_lock before calling update_task_nodemask() and
update_task_cpumask(), instead of using workqueue.
- add documentation in include/linux/cgroup.h
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
effective_cpumask_cpuset() returns an ancestor cpuset which has
non-empty cpumask.
If a cpuset is empty and the tasks in it need to update their
cpus_allowed, they take on the ancestor cpuset's cpumask.
This currently won't change any behavior, but it will later allow us
to keep tasks in empty cpusets.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
When we update a cpuset's mems_allowed and thus update tasks'
mems_allowed, it's required to pass the old mems_allowed and new
mems_allowed to cpuset_migrate_mm().
Currently we save old mems_allowed in a temp local variable before
changing cpuset->mems_allowed. This patch changes it by saving
old mems_allowed in cpuset->old_mems_allowed.
This currently won't change any behavior, but it will later allow
us to keep tasks in empty cpusets.
v3: restored "cpuset_attach_nodemask_to = cs->mems_allowed"
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Merge misc fixes from Andrew Morton:
"Bunch of fixes and one little addition to math64.h"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (27 commits)
include/linux/math64.h: add div64_ul()
mm: memcontrol: fix lockless reclaim hierarchy iterator
frontswap: fix incorrect zeroing and allocation size for frontswap_map
kernel/audit_tree.c:audit_add_tree_rule(): protect `rule' from kill_rules()
mm: migration: add migrate_entry_wait_huge()
ocfs2: add missing lockres put in dlm_mig_lockres_handler
mm/page_alloc.c: fix watermark check in __zone_watermark_ok()
drivers/misc/sgi-gru/grufile.c: fix info leak in gru_get_config_info()
aio: fix io_destroy() regression by using call_rcu()
rtc-at91rm9200: use shadow IMR on at91sam9x5
rtc-at91rm9200: add shadow interrupt mask
rtc-at91rm9200: refactor interrupt-register handling
rtc-at91rm9200: add configuration support
rtc-at91rm9200: add match-table compile guard
fs/ocfs2/namei.c: remove unecessary ERROR when removing non-empty directory
swap: avoid read_swap_cache_async() race to deadlock while waiting on discard I/O completion
drivers/rtc/rtc-twl.c: fix missing device_init_wakeup() when booted with device tree
cciss: fix broken mutex usage in ioctl
audit: wait_for_auditd() should use TASK_UNINTERRUPTIBLE
drivers/rtc/rtc-cmos.c: fix accidentally enabling rtc channel
...
audit_add_tree_rule() must set 'rule->tree = NULL;' firstly, to protect
the rule itself freed in kill_rules().
The reason is when it is killed, the 'rule' itself may have already
released, we should not access it. one example: we add a rule to an
inode, just at the same time the other task is deleting this inode.
The work flow for adding a rule:
audit_receive() -> (need audit_cmd_mutex lock)
audit_receive_skb() ->
audit_receive_msg() ->
audit_receive_filter() ->
audit_add_rule() ->
audit_add_tree_rule() -> (need audit_filter_mutex lock)
...
unlock audit_filter_mutex
get_tree()
...
iterate_mounts() -> (iterate all related inodes)
tag_mount() ->
tag_trunk() ->
create_trunk() -> (assume it is 1st rule)
fsnotify_add_mark() ->
fsnotify_add_inode_mark() -> (add mark to inode->i_fsnotify_marks)
...
get_tree(); (each inode will get one)
...
lock audit_filter_mutex
The work flow for deleting an inode:
__destroy_inode() ->
fsnotify_inode_delete() ->
__fsnotify_inode_delete() ->
fsnotify_clear_marks_by_inode() -> (get mark from inode->i_fsnotify_marks)
fsnotify_destroy_mark() ->
fsnotify_destroy_mark_locked() ->
audit_tree_freeing_mark() ->
evict_chunk() ->
...
tree->goner = 1
...
kill_rules() -> (assume current->audit_context == NULL)
call_rcu() -> (rule->tree != NULL)
audit_free_rule_rcu() ->
audit_free_rule()
...
audit_schedule_prune() -> (assume current->audit_context == NULL)
kthread_run() -> (need audit_cmd_mutex and audit_filter_mutex lock)
prune_one() -> (delete it from prue_list)
put_tree(); (match the original get_tree above)
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
audit_log_start() does wait_for_auditd() in a loop until
audit_backlog_wait_time passes or audit_skb_queue has a room.
If signal_pending() is true this becomes a busy-wait loop, schedule() in
TASK_INTERRUPTIBLE won't block.
Thanks to Guy for fully investigating and explaining the problem.
(akpm: that'll cause the system to lock up on a non-preemptible
uniprocessor kernel)
(Guy: "Our customer was in fact running a uniprocessor machine, and they
reported a system hang.")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Guy Streeter <streeter@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The dmesg_restrict sysctl currently covers the syslog method for access
dmesg, however /dev/kmsg isn't covered by the same protections. Most
people haven't noticed because util-linux dmesg(1) defaults to using the
syslog method for access in older versions. With util-linux dmesg(1)
defaults to reading directly from /dev/kmsg.
To fix /dev/kmsg, let's compare the existing interfaces and what they
allow:
- /proc/kmsg allows:
- open (SYSLOG_ACTION_OPEN) if CAP_SYSLOG since it uses a destructive
single-reader interface (SYSLOG_ACTION_READ).
- everything, after an open.
- syslog syscall allows:
- anything, if CAP_SYSLOG.
- SYSLOG_ACTION_READ_ALL and SYSLOG_ACTION_SIZE_BUFFER, if
dmesg_restrict==0.
- nothing else (EPERM).
The use-cases were:
- dmesg(1) needs to do non-destructive SYSLOG_ACTION_READ_ALLs.
- sysklog(1) needs to open /proc/kmsg, drop privs, and still issue the
destructive SYSLOG_ACTION_READs.
AIUI, dmesg(1) is moving to /dev/kmsg, and systemd-journald doesn't
clear the ring buffer.
Based on the comments in devkmsg_llseek, it sounds like actions besides
reading aren't going to be supported by /dev/kmsg (i.e.
SYSLOG_ACTION_CLEAR), so we have a strict subset of the non-destructive
syslog syscall actions.
To this end, move the check as Josh had done, but also rename the
constants to reflect their new uses (SYSLOG_FROM_CALL becomes
SYSLOG_FROM_READER, and SYSLOG_FROM_FILE becomes SYSLOG_FROM_PROC).
SYSLOG_FROM_READER allows non-destructive actions, and SYSLOG_FROM_PROC
allows destructive actions after a capabilities-constrained
SYSLOG_ACTION_OPEN check.
- /dev/kmsg allows:
- open if CAP_SYSLOG or dmesg_restrict==0
- reading/polling, after open
Addresses https://bugzilla.redhat.com/show_bug.cgi?id=903192
[akpm@linux-foundation.org: use pr_warn_once()]
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Christian Kujau <lists@nerdbynature.de>
Tested-by: Josh Boyer <jwboyer@redhat.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We recently noticed that reboot of a 1024 cpu machine takes approx 16
minutes of just stopping the cpus. The slowdown was tracked to commit
f96972f2dc ("kernel/sys.c: call disable_nonboot_cpus() in
kernel_restart()").
The current implementation does all the work of hot removing the cpus
before halting the system. We are switching to just migrating to the
boot cpu and then continuing with shutdown/reboot.
This also has the effect of not breaking x86's command line parameter
for specifying the reboot cpu. Note, this code was shamelessly copied
from arch/x86/kernel/reboot.c with bits removed pertaining to the
reboot_cpu command line parameter.
Signed-off-by: Robin Holt <holt@sgi.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Russ Anderson <rja@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are instances in the kernel where we would like to disable CPU
hotplug (from sysfs) during some important operation. Today the freezer
code depends on this and the code to do it was kinda tailor-made for
that.
Restructure the code and make it generic enough to be useful for other
usecases too.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Robin Holt <holt@sgi.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Russ Anderson <rja@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
one of the counter clocks. The new multibuffer code changed the trace_clock
file to update the trace instances tr->clock_id but the actual traces still
used the value from the obsolete global variable trace_clock_id.
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Merge tag 'trace-fixes-v3.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"Yoshihiro Yunomae fixed a regression in the output format when using
one of the counter clocks.
The new multibuffer code changed the trace_clock file to update the
trace instances tr->clock_id but the actual traces still used the
value from the obsolete global variable trace_clock_id"
* tag 'trace-fixes-v3.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix outputting formats of x86-tsc and counter when use trace_clock
This adds in a new message to the wakeup code which adds an
indication to the log that suspend was cancelled due to a wake event
occouring during the suspend sequence. It also adjusts the message
printed in suspend.c to reflect the potential that a suspend was
aborted, as opposed to a device failing to suspend.
Without these message adjustments one can end up with a kernel log
that says that a device failed to suspend with no actual device
suspend failures, which can be confusing to the log examiner.
Signed-off-by: Bernie Thompson <bhthompson@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Moving x86 to the generic idle implementation (commit 7d1a9417 "x86:
Use generic idle loop") wreckaged the stack protector.
I stupidly missed that boot_init_stack_canary() must be inlined from a
function which never returns, but I put that call into
arch_cpu_idle_prepare() which of course returns.
I pondered to play tricks with arch_cpu_idle_prepare() first, but then
I noticed, that the other archs which have implemented the
stackprotector (ARM and SH) do not initialize the canary for the
non-boot cpus.
So I decided to move the boot_init_stack_canary() call into
cpu_startup_entry() ifdeffed with an CONFIG_X86 for now. This #ifdef
is just a temporary measure as I don't want to inflict the
boot_init_stack_canary() call on ARM and SH that late in the cycle.
I'll queue a patch for 3.11 which removes the #ifdef if the ARM/SH
maintainers have no objection.
Reported-by: Wouter van Kesteren <woutershep@gmail.com>
Cc: x86@kernel.org
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Outputting formats of x86-tsc and counter should be a raw format, but after
applying the patch(2b6080f28c), the format was
changed to nanosec. This is because the global variable trace_clock_id was used.
When we use multiple buffers, clock_id of each sub-buffer should be used. Then,
this patch uses tr->clock_id instead of the global variable trace_clock_id.
[ Basically, this fixes a regression where the multibuffer code changed the
trace_clock file to update tr->clock_id but the traces still use the old
global trace_clock_id variable, negating the file's effect. The global
trace_clock_id variable is obsolete and removed. - SR ]
Link: http://lkml.kernel.org/r/20130423013239.22334.7394.stgit@yunodevel
Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When a threaded irq handler is installed the irq thread is initially
created on normal scheduling priority. Only after the irq thread is
woken up it sets its priority to RT_FIFO MAX_USER_RT_PRIO/2 itself.
This means that interrupts that occur directly after the irq handler
is installed will be handled on a normal scheduling priority instead
of the realtime priority that one would expect.
Fix this by setting the RT priority on creation of the irq_thread.
Signed-off-by: Ivo Sieben <meltedpianoman@gmail.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1370254322-17240-1-git-send-email-meltedpianoman@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The stop machine logic can lock up if all but one of the migration
threads make it through the disable-irq step and the one remaining
thread gets stuck in __do_softirq. The reason __do_softirq can hang is
that it has a bail-out based on jiffies timeout, but in the lockup case,
jiffies itself is not incremented.
To work around this, re-add the max_restart counter in __do_irq and stop
processing irqs after 10 restarts.
Thanks to Tejun Heo and Rusty Russell and others for helping me track
this down.
This was introduced in 3.9 by commit c10d73671a ("softirq: reduce
latencies").
It may be worth looking into ath9k to see if it has issues with its irq
handler at a later date.
The hang stack traces look something like this:
------------[ cut here ]------------
WARNING: at kernel/watchdog.c:245 watchdog_overflow_callback+0x9c/0xa7()
Watchdog detected hard LOCKUP on cpu 2
Modules linked in: ath9k ath9k_common ath9k_hw ath mac80211 cfg80211 nfsv4 auth_rpcgss nfs fscache nf_nat_ipv4 nf_nat veth 8021q garp stp mrp llc pktgen lockd sunrpc]
Pid: 23, comm: migration/2 Tainted: G C 3.9.4+ #11
Call Trace:
<NMI> warn_slowpath_common+0x85/0x9f
warn_slowpath_fmt+0x46/0x48
watchdog_overflow_callback+0x9c/0xa7
__perf_event_overflow+0x137/0x1cb
perf_event_overflow+0x14/0x16
intel_pmu_handle_irq+0x2dc/0x359
perf_event_nmi_handler+0x19/0x1b
nmi_handle+0x7f/0xc2
do_nmi+0xbc/0x304
end_repeat_nmi+0x1e/0x2e
<<EOE>>
cpu_stopper_thread+0xae/0x162
smpboot_thread_fn+0x258/0x260
kthread+0xc7/0xcf
ret_from_fork+0x7c/0xb0
---[ end trace 4947dfa9b0a4cec3 ]---
BUG: soft lockup - CPU#1 stuck for 22s! [migration/1:17]
Modules linked in: ath9k ath9k_common ath9k_hw ath mac80211 cfg80211 nfsv4 auth_rpcgss nfs fscache nf_nat_ipv4 nf_nat veth 8021q garp stp mrp llc pktgen lockd sunrpc]
irq event stamp: 835637905
hardirqs last enabled at (835637904): __do_softirq+0x9f/0x257
hardirqs last disabled at (835637905): apic_timer_interrupt+0x6d/0x80
softirqs last enabled at (5654720): __do_softirq+0x1ff/0x257
softirqs last disabled at (5654725): irq_exit+0x5f/0xbb
CPU 1
Pid: 17, comm: migration/1 Tainted: G WC 3.9.4+ #11 To be filled by O.E.M. To be filled by O.E.M./To be filled by O.E.M.
RIP: tasklet_hi_action+0xf0/0xf0
Process migration/1
Call Trace:
<IRQ>
__do_softirq+0x117/0x257
irq_exit+0x5f/0xbb
smp_apic_timer_interrupt+0x8a/0x98
apic_timer_interrupt+0x72/0x80
<EOI>
printk+0x4d/0x4f
stop_machine_cpu_stop+0x22c/0x274
cpu_stopper_thread+0xae/0x162
smpboot_thread_fn+0x258/0x260
kthread+0xc7/0xcf
ret_from_fork+0x7c/0xb0
Signed-off-by: Ben Greear <greearb@candelatech.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Pekka Riikonen <priikone@iki.fi>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
TINY_RCU's reset_cpu_stall_ticks() and check_cpu_stalls() functions
are defined unconditionally, and are empty functions if CONFIG_RCU_TRACE
is disabled (which in turns disables detection of RCU CPU stalls).
This commit saves a few lines of source code by defining these functions
only if CONFIG_RCU_TRACE=y.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Now that TINY_PREEMPT_RCU is no more, exit_rcu() is always an empty
function. But if TINY_RCU is going to have an empty function, it should
be in include/linux/rcutiny.h, where it does not bloat the kernel.
This commit therefore moves exit_rcu() out of kernel/rcupdate.c to
kernel/rcutree_plugin.h, and places a static inline empty function in
include/linux/rcutiny.h in order to shrink TINY_RCU a bit.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit rearranges code in order to allow ifdefs to be consolidated
in kernel/rcutiny_plugin.h, simplifying the code.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
With the removal of CONFIG_TINY_PREEMPT_RCU, check_cpu_stall_preempt()
is now an empty function. This commit therefore eliminates it by
inlining it.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
TINY_PREEMPT_RCU could use a kthread to handle RCU callback invocation,
which required an API to abstract kthread vs. softirq invocation.
Now that TINY_PREEMPT_RCU is no longer with us, this commit retires
this API in favor of direct use of the relevant softirq primitives.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
With the removal of CONFIG_TINY_PREEMPT_RCU, rcu_preempt_process_callbacks()
is now an empty function. This commit therefore eliminates it by
inlining it.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
With the removal of CONFIG_TINY_PREEMPT_RCU, rcu_preempt_remove_callbacks()
is now an empty function. This commit therefore eliminates it by
inlining it.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
With the removal of CONFIG_TINY_PREEMPT_RCU, rcu_preempt_check_callbacks()
is now an empty function. This commit therefore eliminates it by
inlining it.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
With the removal of CONFIG_TINY_PREEMPT_RCU, show_tiny_preempt_stats()
is now an empty function. This commit therefore eliminates it by
inlining it.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
TINY_PREEMPT_RCU adds significant code and complexity, but does not
offer commensurate benefits. People currently using TINY_PREEMPT_RCU
can get much better memory footprint with TINY_RCU, or, if they really
need preemptible RCU, they can use TREE_PREEMPT_RCU with a relatively
minor degradation in memory footprint. Please note that this move
has been widely publicized on LKML (https://lkml.org/lkml/2012/11/12/545)
and on LWN (http://lwn.net/Articles/541037/).
This commit therefore removes TINY_PREEMPT_RCU.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Updated to eliminate #else in rcutiny.h as suggested by Josh ]
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
These interfaces never did get used, so this commit removes them,
their rcutorture tests, and documentation referencing them.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Two ifdefs in kernel/rcupdate.c now have identical conditions with
nothing between them, so the commit merges them into a single ifdef.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Systems with HZ=100 can have slow bootup times due to the default
three-jiffy delays between quiescent-state forcing attempts. This
commit therefore auto-tunes the RCU_JIFFIES_TILL_FORCE_QS value based
on the value of HZ. However, this would break very large systems that
require more time between quiescent-state forcing attempts. This
commit therefore also ups the default delay by one jiffy for each
256 CPUs that might be on the system (based off of nr_cpu_ids at
runtime, -not- NR_CPUS at build time).
Updated to collapse #ifdefs for RCU_JIFFIES_TILL_FORCE_QS into a
step-function definition as suggested by Josh Triplett.
Reported-by: Paul Mackerras <paulus@au1.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
After a release or two, features are no longer experimental. Therefore,
this commit removes the "Experimental" tag from them.
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
The __rcu_process_callbacks() invokes note_gp_changes() immediately
before invoking rcu_check_quiescent_state(), which conditionally
invokes that same function. This commit therefore eliminates the
call to note_gp_changes() in __rcu_process_callbacks() in favor of
making unconditional to call from rcu_check_quiescent_state() to
note_gp_changes().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Given the changes that introduce note_gp_change(), rcu_start_gp_per_cpu()
is now a trivial wrapper function with only one caller. This commit
therefore inlines it into its sole call site.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
One of the calls to check_for_new_grace_period() is now redundant due to
an immediately preceding call to note_gp_changes(). Eliminating this
redundant call leaves a single caller, which is simpler if inlined.
This commit therefore eliminates the redundant call and inlines the
body of check_for_new_grace_period() into the single remaining call site.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit eliminates some duplicated code by merging
__rcu_process_gp_end() into __note_gp_changes().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Because note_gp_changes() now incorporates rcu_process_gp_end() function,
this commit switches to the former and eliminates the latter. In
addition, this commit changes external calls from __rcu_process_gp_end()
to __note_gp_changes().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit converts printk() calls to the corresponding pr_*() calls.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Because note_new_gpnum() now also checks for the ends of old grace periods,
this commit changes its name to note_gp_changes(). Later commits will merge
rcu_process_gp_end() into note_gp_changes().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
The current implementation can detect the beginning of a new grace period
before noting the end of a previous grace period. Although the current
implementation correctly handles this sort of nonsense, it would be
good to reduce RCU's state space by making such nonsense unnecessary,
which is now possible thanks to the fact that RCU's callback groups are
now numbered.
This commit therefore makes __note_new_gpnum() invoke
__rcu_process_gp_end() in order to note the ends of prior grace
periods before noting the beginnings of new grace periods.
Of course, this now means that note_new_gpnum() notes both the
beginnings and ends of grace periods, and could therefore be
used in place of rcu_process_gp_end(). But that is a job for
later commits.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
The addition of callback numbering allows combining the detection of the
ends of old grace periods and the beginnings of new grace periods. This
commit moves code to set the stage for this combining.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit converts printk() calls to the corresponding pr_*() calls.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
As we can drop rcu read lock while iterating cgroup hierarchy,
we don't have to do propagation asynchronously via workqueue.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Instead of triggering propagation work in cpuset_attach(), we make
hotplug propagation work wait until there's no task attaching in
progress.
IMO this is more robust. We won't see empty masks in cpuset_attach().
Also it's a preparation for removing propagation work. Without asynchronous
propagation we can't call move_tasks_in_empty_cpuset() in cpuset_attach(),
because otherwise we'll deadlock on cgroup_mutex.
tj: typo fixes.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Pull timer fixes from Thomas Gleixner:
- Trivial: unused variable removal
- Posix-timers: Add the clock ID to the new proc interface to make it
useful. The interface is new and should be functional when we reach
the final 3.10 release.
- Cure a false positive warning in the tick code introduced by the
overhaul in 3.10
- Fix for a persistent clock detection regression introduced in this
cycle
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timekeeping: Correct run-time detection of persistent_clock.
ntp: Remove unused variable flags in __hardpps
posix-timers: Show clock ID in proc file
tick: Cure broadcast false positive pending bit warning
This branch contains a set of straight forward bug fixes to the
irqdomain code and to a couple of drivers that make use of it.
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Merge tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux
Pull irqdomain bug fixes from Grant Likely:
"This branch contains a set of straight forward bug fixes to the
irqdomain code and to a couple of drivers that make use of it."
* tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux:
irqchip: Return -EPERM for reserved IRQs
irqdomain: document the simple domain first_irq
kernel/irq/irqdomain.c: before use 'irq_data', need check it whether valid.
irqdomain: export irq_domain_add_simple
The first_irq needs to be zero to get a linear domain and that
comes with special semantics. We want to simplify this going
forward but some documentation never hurts.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
Since irq_data may be NULL, if so, we WARN_ON(), and continue, 'hwirq'
which related with 'irq_data' has to initialize later, or it will cause
issue.
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
All other irq_domain_add_* functions are exported already, and apparently
this one got left out by mistake, which causes build errors for ARM
allmodconfig kernels:
ERROR: "irq_domain_add_simple" [drivers/gpio/gpio-rcar.ko] undefined!
ERROR: "irq_domain_add_simple" [drivers/gpio/gpio-em.ko] undefined!
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
The first two fix the case where full RCU debugging is enabled, enabling
function tracing causes a live lock of the system. This is due to the added
debug checks in rcu_dereference_raw() that is used by the function tracer.
These checks are also traced by the function tracer as well as cause enough
overhead to the function tracer to slow down the system enough that
the time to finish an interrupt can take longer than when the next
interrupt is triggered, causing a live lock from the timer interrupt.
Talking this over with Paul McKenney, we came up with a fix that adds
a new rcu_dereference_raw_notrace() that does not perform these added checks,
and let the function tracer use that.
The third commit fixes a failed compile when branch tracing is enabled,
due to the conversion of the trace_test_buffer() selftest that the
branch trace wasn't converted for.
The forth patch fixes a bug caught by the RCU lockdep code where a
rcu_read_lock() is performed when rcu is disabled (either going to
or from idle, or user space). This happened on the irqsoff tracer
as it calls task_uid(). The fix here was to use current_uid() when
possible that doesn't use rcu locking. Which luckily, is always used
when irqsoff calls this code.
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Merge tag 'trace-fixes-v3.10-rc3-v3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"This contains 4 fixes.
The first two fix the case where full RCU debugging is enabled,
enabling function tracing causes a live lock of the system. This is
due to the added debug checks in rcu_dereference_raw() that is used by
the function tracer. These checks are also traced by the function
tracer as well as cause enough overhead to the function tracer to slow
down the system enough that the time to finish an interrupt can take
longer than when the next interrupt is triggered, causing a live lock
from the timer interrupt.
Talking this over with Paul McKenney, we came up with a fix that adds
a new rcu_dereference_raw_notrace() that does not perform these added
checks, and let the function tracer use that.
The third commit fixes a failed compile when branch tracing is
enabled, due to the conversion of the trace_test_buffer() selftest
that the branch trace wasn't converted for.
The forth patch fixes a bug caught by the RCU lockdep code where a
rcu_read_lock() is performed when rcu is disabled (either going to or
from idle, or user space). This happened on the irqsoff tracer as it
calls task_uid(). The fix here was to use current_uid() when possible
that doesn't use rcu locking. Which luckily, is always used when
irqsoff calls this code."
* tag 'trace-fixes-v3.10-rc3-v3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Use current_uid() for critical time tracing
tracing: Fix bad parameter passed in branch selftest
ftrace: Use the rcu _notrace variants for rcu_dereference_raw() and friends
rcu: Add _notrace variation of rcu_dereference_raw() and hlist_for_each_entry_rcu()
When param1 is enabled in EINJ but not assigned with a valid
value, sometimes it will cause the error like below:
APEI: Can not request [mem 0x7aaa7000-0x7aaa7007] for APEI EINJ Trigger registers
It is because some firmware will access target address specified in
param1 to trigger the error when injecting memory error. This will
cause resource conflict with regular memory. So It must be removed
from trigger table resources, but incorrect param1/param2
combination will stop this action. Add extra check to avoid
this kind of error.
Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
The irqsoff tracer records the max time that interrupts are disabled.
There are hooks in the assembly code that calls back into the tracer when
interrupts are disabled or enabled.
When they are enabled, the tracer checks if the amount of time they
were disabled is larger than the previous recorded max interrupts off
time. If it is, it creates a snapshot of the currently running trace
to store where the last largest interrupts off time was held and how
it happened.
During testing, this RCU lockdep dump appeared:
[ 1257.829021] ===============================
[ 1257.829021] [ INFO: suspicious RCU usage. ]
[ 1257.829021] 3.10.0-rc1-test+ #171 Tainted: G W
[ 1257.829021] -------------------------------
[ 1257.829021] /home/rostedt/work/git/linux-trace.git/include/linux/rcupdate.h:780 rcu_read_lock() used illegally while idle!
[ 1257.829021]
[ 1257.829021] other info that might help us debug this:
[ 1257.829021]
[ 1257.829021]
[ 1257.829021] RCU used illegally from idle CPU!
[ 1257.829021] rcu_scheduler_active = 1, debug_locks = 0
[ 1257.829021] RCU used illegally from extended quiescent state!
[ 1257.829021] 2 locks held by trace-cmd/4831:
[ 1257.829021] #0: (max_trace_lock){......}, at: [<ffffffff810e2b77>] stop_critical_timing+0x1a3/0x209
[ 1257.829021] #1: (rcu_read_lock){.+.+..}, at: [<ffffffff810dae5a>] __update_max_tr+0x88/0x1ee
[ 1257.829021]
[ 1257.829021] stack backtrace:
[ 1257.829021] CPU: 3 PID: 4831 Comm: trace-cmd Tainted: G W 3.10.0-rc1-test+ #171
[ 1257.829021] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS SDBLI944.86P 05/08/2007
[ 1257.829021] 0000000000000001 ffff880065f49da8 ffffffff8153dd2b ffff880065f49dd8
[ 1257.829021] ffffffff81092a00 ffff88006bd78680 ffff88007add7500 0000000000000003
[ 1257.829021] ffff88006bd78680 ffff880065f49e18 ffffffff810daebf ffffffff810dae5a
[ 1257.829021] Call Trace:
[ 1257.829021] [<ffffffff8153dd2b>] dump_stack+0x19/0x1b
[ 1257.829021] [<ffffffff81092a00>] lockdep_rcu_suspicious+0x109/0x112
[ 1257.829021] [<ffffffff810daebf>] __update_max_tr+0xed/0x1ee
[ 1257.829021] [<ffffffff810dae5a>] ? __update_max_tr+0x88/0x1ee
[ 1257.829021] [<ffffffff811002b9>] ? user_enter+0xfd/0x107
[ 1257.829021] [<ffffffff810dbf85>] update_max_tr_single+0x11d/0x12d
[ 1257.829021] [<ffffffff811002b9>] ? user_enter+0xfd/0x107
[ 1257.829021] [<ffffffff810e2b15>] stop_critical_timing+0x141/0x209
[ 1257.829021] [<ffffffff8109569a>] ? trace_hardirqs_on+0xd/0xf
[ 1257.829021] [<ffffffff811002b9>] ? user_enter+0xfd/0x107
[ 1257.829021] [<ffffffff810e3057>] time_hardirqs_on+0x2a/0x2f
[ 1257.829021] [<ffffffff811002b9>] ? user_enter+0xfd/0x107
[ 1257.829021] [<ffffffff8109550c>] trace_hardirqs_on_caller+0x16/0x197
[ 1257.829021] [<ffffffff8109569a>] trace_hardirqs_on+0xd/0xf
[ 1257.829021] [<ffffffff811002b9>] user_enter+0xfd/0x107
[ 1257.829021] [<ffffffff810029b4>] do_notify_resume+0x92/0x97
[ 1257.829021] [<ffffffff8154bdca>] int_signal+0x12/0x17
What happened was entering into the user code, the interrupts were enabled
and a max interrupts off was recorded. The trace buffer was saved along with
various information about the task: comm, pid, uid, priority, etc.
The uid is recorded with task_uid(tsk). But this is a macro that uses rcu_read_lock()
to retrieve the data, and this happened to happen where RCU is blind (user_enter).
As only the preempt and irqs off tracers can have this happen, and they both
only have the tsk == current, if tsk == current, use current_uid() instead of
task_uid(), as current_uid() does not use RCU as only current can change its uid.
This fixes the RCU suspicious splat.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Check if cpus_allowed is to be changed before calling validate_change().
This won't change any behavior, but later it will allow us to do this:
# mkdir /cpuset/child
# echo $$ > /cpuset/child/tasks /* empty cpuset */
# echo > /cpuset/child/cpuset.cpus /* do nothing, won't fail */
Without this patch, the last operation will fail.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
- We never pass a NULL @cs to these functions.
- The top cpuset always has some online cpus/mems.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
* Rename it from files[] (really?) to cgroup_base_files[].
* Drop CGROUP_FILE_GENERIC_PREFIX which was defined as "cgroup." and
used inconsistently. Just use "cgroup." directly.
* Collect insane files at the end. Note that only the insane ones are
missing "cgroup." prefix.
This patch doesn't introduce any functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
The empty cgroup notification mechanism currently implemented in
cgroup is tragically outdated. Forking and execing userland process
stopped being a viable notification mechanism more than a decade ago.
We're gonna have a saner mechanism. Let's make it clear that this
abomination is going away.
Mark "notify_on_release" and "release_agent" with CFTYPE_INSANE.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Some resources controlled by cgroup aren't per-task and cgroup core
allowing threads of a single thread_group to be in different cgroups
forced memcg do explicitly find the group leader and use it. This is
gonna be nasty when transitioning to unified hierarchy and in general
we don't want and won't support granularity finer than processes.
Mark "tasks" with CFTYPE_INSANE.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: cgroups@vger.kernel.org
Cc: Vivek Goyal <vgoyal@redhat.com>
Ever since commit 45f035ab9b ("CONFIG_HOTPLUG should be always on"),
it has been basically impossible to build a kernel with CONFIG_HOTPLUG
turned off. Remove all the remaining references to it.
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Doug Thompson <dougthompson@xmission.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Print physical address info in a style consistent with the %pR style
used elsewhere in the kernel.
Commit 69f1d475cc did this for a similar printk in this file, but I
must have missed this one.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull cgroup fixes from Tejun Heo:
- Fix for yet another xattr bug which may lead to NULL deref.
- A subtle bug in for_each_descendant_pre(). This bug requires quite
specific conditions to trigger and isn't too likely to actually
happen in the wild, but maybe that just makes it that much more
nastier.
- A warning message added for silly cgroup re-mount (not -o remount,
but unmount followed by mount) behavior.
* 'for-3.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: warn about mismatching options of a new mount of an existing hierarchy
cgroup: fix a subtle bug in descendant pre-order walk
cgroup: initialize xattr before calling d_instantiate()
Since 7300711e ("clockevents: broadcast fixup possible waiters"),
the timekeeping duty is assigned to the CPU that handles the tick
broadcast clock device by the time it is set in one shot mode.
This is an issue in full dynticks mode where the timekeeping duty
must stay handled by the boot CPU for now. Otherwise it prevents
secondary CPUs from offlining and this breaks
suspend/shutdown/reboot/...
As it appears there is no reason for this timekeeping duty to be
moved to the broadcast CPU, besides nothing prevent it from being
later re-assigned to another target, let's simply remove it.
Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit 78becc2709 ("sched: Use an accessor to read the rq clock")
introduces rq_clock(), which obsoletes the use of the "rq" variable
in expire_cfs_rq_runtime() and triggers this build warning:
kernel/sched/fair.c: In function 'expire_cfs_rq_runtime':
kernel/sched/fair.c:2159:13: warning: unused variable 'rq' [-Wunused-variable]
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Paul Turner <pjt@google.com>
Cc: peterz@infradead.org
Link: http://lkml.kernel.org/r/1369904660-14169-1-git-send-email-kamalesh@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In tick_nohz_cpu_down_callback() if the cpu is the one handling
timekeeping, we must return something that stops the CPU_DOWN_PREPARE
notifiers and then start notify CPU_DOWN_FAILED on the already called
notifier call backs.
However traditional errno values are not handled by the notifier unless
these are encapsulated using errno_to_notifier().
Hence the current -EINVAL is misinterpreted and converted to junk after
notifier_to_errno(), leaving the notifier subsystem to random behaviour
such as eventually allowing the cpu to go down.
Fix this by using the standard NOTIFY_BAD instead.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The kvm_host.h header file doesn't handle well
inclusion when archs don't support KVM.
This results in build crashes for such archs when they
want to implement context tracking because this subsystem
includes kvm_host.h in order to implement the
guest_enter/exit APIs but it doesn't handle KVM off case.
To fix this, move the guest_enter()/guest_exit()
declarations and generic implementation to the context
tracking headers. These generic APIs actually belong to
this subsystem, besides other domains boundary tracking
like user_enter() et al.
KVM now properly becomes a user of this library, not the
other buggy way around.
Reported-by: Kevin Hilman <khilman@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
While computing the cputime delta of dynticks CPUs,
we are mixing up clocks of differents natures:
* local_clock() which takes care of unstable clock
sources and fix these if needed.
* sched_clock() which is the weaker version of
local_clock(). It doesn't compute any fixup in case
of unstable source.
If the clock source is stable, those two clocks are the
same and we can safely compute the difference against
two random points.
Otherwise it results in random deltas as sched_clock()
can randomly drift away, back or forward, from local_clock().
As a consequence, some strange behaviour with unstable tsc
has been observed such as non progressing constant zero cputime.
(The 'top' command showing no load).
Fix this by only using local_clock(), or its irq safe/remote
equivalent, in vtime code.
Reported-by: Mike Galbraith <efault@gmx.de>
Suggested-by: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 fixes from Peter Anvin:
- Three EFI-related fixes
- Two early memory initialization fixes
- build fix for older binutils
- fix for an eager FPU performance regression -- currently we don't
allow the use of the FPU at interrupt time *at all* in eager mode,
which is clearly wrong.
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Allow FPU to be used at interrupt time even with eagerfpu
x86, crc32-pclmul: Fix build with older binutils
x86-64, init: Fix a possible wraparound bug in switchover in head_64.S
x86, range: fix missing merge during add range
x86, efi: initial the local variable of DataSize to zero
efivar: fix oops in efivar_update_sysfs_entries() caused by memory reuse
efivarfs: Never return ENOENT from firmware again
The branch selftest calls trace_test_buffer(), but with the new code
it expects the first parameter to be a pointer to a struct trace_buffer.
All self tests were changed but the branch selftest was missed.
This caused either a crash or failed test when the branch selftest was
enabled.
Link: http://lkml.kernel.org/r/20130529141333.GA24064@localhost
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Some controllers have irqs that aren't wired up and must never be used.
For the generic chip attached to an irq_domain this provides a mask that
can be used to block out particular irqs so that they never get mapped.
Signed-off-by: Grant Likely <grant.likely@linaro.org>
Link: http://lkml.kernel.org/r/1369793454-19197-2-git-send-email-grant.likely@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Provide infrastructure for irq chip implementations which work on
linear irq domains.
- Interface to allocate multiple generic chips which are associated to
the irq domain.
- Interface to get the generic chip pointer for a particular hardware
interrupt in the domain.
- irq domain mapping function to install the chip for a particular
interrupt.
Note: This lacks a removal function for now.
[ Sebastian Hesselbarth: Mask cache and pointer math fixups ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jean-Francois Moine <moinejf@free.fr>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Cc: Gerlando Falauto <gerlando.falauto@keymile.com>
Cc: Rob Landley <rob@landley.net>
Acked-by: Grant Likely <grant.likely@linaro.org>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Link: http://lkml.kernel.org/r/20130506142539.450634298@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Preparatory patch for linear interrupt domains.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jean-Francois Moine <moinejf@free.fr>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Cc: Gerlando Falauto <gerlando.falauto@keymile.com>
Cc: Rob Landley <rob@landley.net>
Acked-by: Grant Likely <grant.likely@linaro.org>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Link: http://lkml.kernel.org/r/20130506142539.377017672@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Some chips have weird bit mask access patterns instead of the linear
you expect. Allow them to calculate the cached mask themself.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jean-Francois Moine <moinejf@free.fr>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Cc: Gerlando Falauto <gerlando.falauto@keymile.com>
Cc: Rob Landley <rob@landley.net>
Acked-by: Grant Likely <grant.likely@linaro.org>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Link: http://lkml.kernel.org/r/20130506142539.302898834@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cache the per irq bit mask instead of recalculating it over and over.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jean-Francois Moine <moinejf@free.fr>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Cc: Gerlando Falauto <gerlando.falauto@keymile.com>
Cc: Rob Landley <rob@landley.net>
Acked-by: Grant Likely <grant.likely@linaro.org>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Link: http://lkml.kernel.org/r/20130506142539.227119865@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
There are cases where all irq_chip_type instances have separate mask
registers, making a shared mask register cache unsuitable for the
purpose.
Introduce a new flag IRQ_GC_MASK_CACHE_PER_TYPE. If set, point the per
chip mask pointer to the per chip private mask cache instead.
[ tglx: Simplified code, renamed flag and massaged changelog ]
Signed-off-by: Gerlando Falauto <gerlando.falauto@keymile.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Joey Oravec <joravec@drewtech.com>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Cc: Holger Brunck <Holger.Brunck@keymile.com>
Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Cc: Simon Guinot <simon@sequanux.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Jean-Francois Moine <moinejf@free.fr>
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Rob Landley <rob@landley.net>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: http://lkml.kernel.org/r/20130506142539.152569748@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Today the same interrupt mask cache (stored within struct irq_chip_generic)
is shared between all the irq_chip_type instances. As there are instances
where each irq_chip_type uses a distinct mask register (as it is the case
for Orion SoCs), sharing a single mask cache may be incorrect.
So add a distinct pointer for each irq_chip_type, which for now
points to the original mask register within irq_chip_generic.
So no functional changes here.
[ tglx: Minor cosmetic tweaks ]
Reported-by: Joey Oravec <joravec@drewtech.com>
Signed-off-by: Simon Guinot <sguinot@lacie.com>
Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
Signed-off-by: Gerlando Falauto <gerlando.falauto@keymile.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Cc: Holger Brunck <Holger.Brunck@keymile.com>
Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Cc: Simon Guinot <simon@sequanux.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Jean-Francois Moine <moinejf@free.fr>
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Rob Landley <rob@landley.net>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: http://lkml.kernel.org/r/20130506142539.082226607@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Since we already have an irq_data_get_chip_type() function which returns
a pointer to irq_chip_type, use that instead of cur_regs().
Signed-off-by: Gerlando Falauto <gerlando.falauto@keymile.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Joey Oravec <joravec@drewtech.com>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Cc: Holger Brunck <Holger.Brunck@keymile.com>
Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Cc: Simon Guinot <simon@sequanux.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Jean-Francois Moine <moinejf@free.fr>
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Rob Landley <rob@landley.net>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: http://lkml.kernel.org/r/20130506142539.010164766@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
As rcu_dereference_raw() under RCU debug config options can add quite a
bit of checks, and that tracing uses rcu_dereference_raw(), these checks
happen with the function tracer. The function tracer also happens to trace
these debug checks too. This added overhead can livelock the system.
Have the function tracer use the new RCU _notrace equivalents that do
not do the debug checks for RCU.
Link: http://lkml.kernel.org/r/20130528184209.467603904@goodmis.org
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
With the new __DEVEL__sane_behavior mount option was introduced,
if the root cgroup is alive with no xattr function, to mount a
new cgroup with xattr will be rejected in terms of design which
just fine. However, if the root cgroup does not mounted with
__DEVEL__sane_hehavior, to create a new cgroup with xattr option
will succeed although after that the EA function does not works
as expected but will get ENOTSUPP for setting up attributes under
either cgroup. e.g.
setfattr: /cgroup2/test: Operation not supported
Instead of keeping silence in this case, it's better to drop a log
entry in warning level. That would be helpful to understand the
reason behind the scene from the user's perspective, and this is
essentially an improvement does not break the backward compatibilities.
With this fix, above mount attemption will keep up works as usual but
the following line cound be found at the system log:
[ ...] cgroup: new mount options do not match the existing superblock
tj: minor formatting / message updates.
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Reported-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
Since commit 31ade30692, timekeeping_init()
checks for presence of persistent clock by attempting to read a non-zero
time value. This is an issue on platforms where persistent_clock (instead
is implemented as a free-running counter (instead of an RTC) starting
from zero on each boot and running during suspend. Examples are some ARM
platforms (e.g. PandaBoard).
An attempt to read such a clock during timekeeping_init() may return zero
value and falsely declare persistent clock as missing. Additionally, in
the above case suspend times may be accounted twice (once from
timekeeping_resume() and once from rtc_resume()), resulting in a gradual
drift of system time.
This patch does a run-time correction of the issue by doing the same check
during timekeeping_suspend().
A better long-term solution would have to return error when trying to read
non-existing clock and zero when trying to read an uninitialized clock, but
that would require changing all persistent_clock implementations.
This patch addresses the immediate breakage, for now.
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Feng Tang <feng.tang@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Zoran Markovic <zoran.markovic@linaro.org>
[jstultz: Tweaked commit message and subject]
Signed-off-by: John Stultz <john.stultz@linaro.org>
kernel/time/ntp.c: In function ‘__hardpps’:
kernel/time/ntp.c:877: warning: unused variable ‘flags’
commit a076b2146f ("ntp: Remove ntp_lock,
using the timekeeping locks to protect ntp state") removed its users,
but not the actual variable.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
The first one was reported by Mauro Carvalho Chehab, where if a poll()
is done against a trace buffer for a CPU that has never been online,
it will crash the kernel, as buffers are only created when a CPU comes
on line, but the trace files are for all possible CPUs.
This fix is to check if the buffer was allocated and if not return -EINVAL.
That was the simple fix, the real fix is a bit more complex and not for
a -rc release. We could have the files created when the CPUs come online.
That would require some design changes.
The second one was reported by Peter Zijlstra. If the kernel command line
has ftrace=nop, it will lock up the system on boot up. This is because
the new design for 3.10 has the nop tracer bootstrap the tracing subsystem.
When ftrace=<trace> is defined, when a that tracer is registered, it
starts the tracing, but uses the nop tracer to clear things out.
What happened here was that ftrace=nop caused the registering of nop
to start it and use nop before it was initialized.
The only thing nop needs to have done to initialize it is to have the
tracer point its current_tracer structure member to the nop tracer.
Doing that before registering the nop tracer makes everything work.
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Merge tag 'trace-fixes-v3.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"Two more fixes:
The first one was reported by Mauro Carvalho Chehab, where if a poll()
is done against a trace buffer for a CPU that has never been online,
it will crash the kernel, as buffers are only created when a CPU comes
on line, but the trace files are for all possible CPUs.
This fix is to check if the buffer was allocated and if not return
-EINVAL.
That was the simple fix, the real fix is a bit more complex and not
for a -rc release. We could have the files created when the CPUs come
online. That would require some design changes.
The second one was reported by Peter Zijlstra. If the kernel command
line has ftrace=nop, it will lock up the system on boot up. This is
because the new design for 3.10 has the nop tracer bootstrap the
tracing subsystem. When ftrace=<trace> is defined, when a that tracer
is registered, it starts the tracing, but uses the nop tracer to clear
things out. What happened here was that ftrace=nop caused the
registering of nop to start it and use nop before it was initialized.
The only thing nop needs to have done to initialize it is to have the
tracer point its current_tracer structure member to the nop tracer.
Doing that before registering the nop tracer makes everything work."
* tag 'trace-fixes-v3.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ring-buffer: Do not poll non allocated cpu buffers
tracing: Fix crash when ftrace=nop on the kernel command line
The tracing infrastructure sets up for possible CPUs, but it uses
the ring buffer polling, it is possible to call the ring buffer
polling code with a CPU that hasn't been allocated. This will cause
a kernel oops when it access a ring buffer cpu buffer that is part
of the possible cpus but hasn't been allocated yet as the CPU has never
been online.
Reported-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Tested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In old kernels, it's allowed to set softlockup_thresh to -1 or 0
to disable softlockup detection. However watchdog_thresh only
uses 0 to disable detection, and setting it to -1 just froze my
box and nothing I can do but reboot.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/r/51959668.9040106@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Vince reported a problem found by his perf specific trinity
fuzzer.
Al noticed 2 problems with perf's mmap():
- it has issues against fork() since we use vma->vm_mm for accounting.
- it has an rb refcount leak on double mmap().
We fix the issues against fork() by using VM_DONTCOPY; I don't
think there's code out there that uses this; we didn't hear
about weird accounting problems/crashes. If we do need this to
work, the previously proposed VM_PINNED could make this work.
Aside from the rb reference leak spotted by Al, Vince's example
prog was indeed doing a double mmap() through the use of
perf_event_set_output().
This exposes another problem, since we now have 2 events with
one buffer, the accounting gets screwy because we account per
event. Fix this by making the buffer responsible for its own
accounting.
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/20130528085548.GA12193@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Fix to free gone and unused optprobes. This bug will
cause a kernel panic if the user reuses the killed and
unused probe.
Reported at:
http://sourceware.org/ml/systemtap/2013-q2/msg00142.html
In the normal path, an optprobe on an init function is
unregistered when a module goes live.
unregister_kprobe(kp)
-> __unregister_kprobe_top
->__disable_kprobe
->disarm_kprobe(ap == op)
->__disarm_kprobe
->unoptimize_kprobe : the op is queued
on unoptimizing_list
and do nothing in __unregister_kprobe_bottom
After a while (usually wait 5 jiffies), kprobe_optimizer
runs to unoptimize and free optprobe.
kprobe_optimizer
->do_unoptimize_kprobes
->arch_unoptimize_kprobes : moved to free_list
->do_free_cleaned_kprobes
->hlist_del: the op is removed
->free_aggr_kprobe
->arch_remove_optimized_kprobe
->arch_remove_kprobe
->kfree: the op is freed
Here, if kprobes_module_callback is called and the delayed
unoptimizing probe is picked BEFORE kprobe_optimizer runs,
kprobes_module_callback
->kill_kprobe
->kill_optimized_kprobe : dequeued from unoptimizing_list <=!!!
->arch_remove_optimized_kprobe
->arch_remove_kprobe
(but op is not freed, and on the kprobe hash table)
This doesn't happen if the probe unregistration is done AFTER
kprobes_module_callback is called (because at that time the op
is gone), and kprobe-tracer does it.
To fix this bug, this patch changes kprobes_module_callback to
enqueue the op to freeing_list at kill_optimized_kprobe only
if the op is unused. The unused probes on freeing_list will
be freed in do_free_cleaned_kprobes.
Note that this calls arch_remove_*kprobe twice on the
same probe. Thus those functions have to check the double free.
Fortunately, most of arch codes already checked that except
for mips. This will be fixed in the next patch.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Timo Juhani Lindfors <timo.lindfors@iki.fi>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: systemtap@sourceware.org
Cc: yrl.pp-manager.tt@hitachi.com
Cc: David S. Miller <davem@davemloft.net>
Cc: "David S. Miller" <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20130522093409.9084.63554.stgit@mhiramat-M0-7522
[ Minor edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Read the runqueue clock through an accessor. This
prepares for adding a debugging infrastructure to
detect missing or redundant calls to update_rq_clock()
between a scheduler's entry and exit point.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Turner <pjt@google.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1365724262-20142-6-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In this function we are making use of rq->clock right before the
update of the rq clock, let's just call update_rq_clock() just
before that to avoid using a stale rq clock value.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Turner <pjt@google.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1365724262-20142-5-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
check_preempt_curr() of fair class needs an uptodate sched clock
value to update runtime stats of the current task of the target's rq.
When a task is woken up, activate_task() is usually called right before
ttwu_do_wakeup() unless the task is still in the runqueue. In the latter
case we need to update the rq clock explicitly because activate_task()
isn't here to do the job for us.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Turner <pjt@google.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1365724262-20142-4-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Because we may update the execution time in
sched_group_set_shares()->update_cfs_shares()->reweight_entity()->update_curr()
before reweighting the entity while setting the group shares and this requires
an uptodate version of the runqueue clock.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Turner <pjt@google.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1365724262-20142-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Because the sched_class::put_prev_task() callback of rt and fair
classes are referring to the rq clock to update their runtime
statistics. There is a missing rq clock update from the CPU
hotplug notifier's entry point of the scheduler.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Turner <pjt@google.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1365724262-20142-2-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
migration_call() will do all the things that update_runtime() does.
So let's remove it.
Furthermore, there is potential risk that the current code will catch
BUG_ON at line 689 of rt.c when do cpu hotplug while there are realtime
threads running because of enabling runtime twice while the rt_runtime
may already changed.
Signed-off-by: Neil Zhang <zhangwm@marvell.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1365685499-26515-1-git-send-email-zhangwm@marvell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In autogroup_create(), a tg is allocated and added to the task_groups
list. If CONFIG_RT_GROUP_SCHED is set, this tg is then modified while on
the list, without locking. This can race with someone walking the list,
like __enable_runtime() during CPU unplug, and result in a use-after-free
bug.
To fix this, move sched_online_group(), which adds the tg to the list,
to the end of the autogroup_create() function after the modification.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1369411669-46971-2-git-send-email-gerald.schaefer@de.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
commit 26517f3e (tick: Avoid programming the local cpu timer if
broadcast pending) added a warning if the cpu enters broadcast mode
again while the pending bit is still set. Meelis reported that the
warning triggers. There are two corner cases which have been not
considered:
1) cpuidle calls clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER)
twice. That can result in the following scenario
CPU0 CPU1
cpuidle_idle_call()
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER)
set cpu in tick_broadcast_oneshot_mask
broadcast interrupt
event expired for cpu1
set pending bit
acpi_idle_enter_simple()
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER)
WARN_ON(pending bit)
Move the WARN_ON into the section where we enter broadcast mode so
it wont provide false positives on the second call.
2) safe_halt() enables interrupts, so a broadcast interrupt can be
delivered befor the broadcast mode is disabled. That sets the
pending bit for the CPU which receives the broadcast
interrupt. Though the interrupt is delivered right away from the
broadcast handler and leaves the pending bit stale.
Clear the pending bit for the current cpu in the broadcast handler.
Reported-and-tested-by: Meelis Roos <mroos@linux.ee>
Cc: Len Brown <lenb@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1305271841130.4220@ionos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Parameters and usage of rt_mutex_adjust_prio_chain() are already
documented in Documentation/rt-mutex-design.txt. However, since this
function is called from several paths with different semantics (related
to the arguments), it is handy to have a quick reference directly in
the code.
Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1368608650-7935-1-git-send-email-juri.lelli@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch moves commit 7cc23cd to the generic code:
perf/x86/intel/lbr: Demand proper privileges for PERF_SAMPLE_BRANCH_KERNEL
The check is now implemented in generic code instead of x86 specific
code. That way we do not have to repeat the test in each arch
supporting branch sampling.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lkml.kernel.org/r/20130521105337.GA2879@quad
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch adds /sys/device/xxx/perf_event_mux_interval_ms to ajust
the multiplexing interval per PMU. The unit is milliseconds. Value has
to be >= 1.
In the 4th version, we renamed the sysfs file to be more consistent
with the other /proc/sys/kernel entries for perf_events.
In the 5th version, we handle the reprogramming of the hrtimer using
hrtimer_forward_now(). That way, we sync up to new timer value quickly
(suggested by Jiri Olsa).
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lkml.kernel.org/r/1364991694-5876-3-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The current scheme of using the timer tick was fine for per-thread
events. However, it was causing bias issues in system-wide mode
(including for uncore PMUs). Event groups would not get their fair
share of runtime on the PMU. With tickless kernels, if a core is idle
there is no timer tick, and thus no event rotation (multiplexing).
However, there are events (especially uncore events) which do count
even though cores are asleep.
This patch changes the timer source for multiplexing. It introduces a
per-PMU per-cpu hrtimer. The advantage is that even when a core goes
idle, it will come back to service the hrtimer, thus multiplexing on
system-wide events works much better.
The per-PMU implementation (suggested by PeterZ) enables adjusting the
multiplexing interval per PMU. The preferred interval is stashed into
the struct pmu. If not set, it will be forced to the default interval
value.
In order to minimize the impact of the hrtimer, it is turned on and
off on demand. When the PMU on a CPU is overcommited, the hrtimer is
activated. It is stopped when the PMU is not overcommitted.
In order for this to work properly, we had to change the order of
initialization in start_kernel() such that hrtimer_init() is run
before perf_event_init().
The default interval in milliseconds is set to a timer tick just like
with the old code. We will provide a sysctl to tune this in another
patch.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lkml.kernel.org/r/1364991694-5876-2-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The hw breakpoint pmu 'add' function is missing the
period_left update needed for SW events.
The perf HW breakpoint events use the SW events framework
to process the overflow, so it needs to be properly initialized
in the PMU 'add' method.
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1367421944-19082-5-git-send-email-jolsa@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The Kconfig symbols ARCH_INLINE_READ_UNLOCK_IRQ,
ARCH_INLINE_SPIN_UNLOCK_IRQ, and ARCH_INLINE_WRITE_UNLOCK_IRQ were added
in v2.6.33, but have never actually been used. Ingo Molnar spotted that
this is caused by three identical copy/paste erros. Eg, the Kconfig
entry for
INLINE_READ_UNLOCK_IRQ
has an (optional) dependency on:
ARCH_INLINE_READ_UNLOCK_BH
were it apparently should depend on:
ARCH_INLINE_READ_UNLOCK_IRQ
instead. Likewise for the Kconfig entries for INLINE_SPIN_UNLOCK_IRQ and
INLINE_WRITE_UNLOCK_IRQ. Fix these three errors.
This never really caused any real problems as these symbols are set (or
unset) in a group - but it's worth fixing it nevertheless.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1368780693.1350.228.camel@x61.thuisdomein
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Fix kernel-doc warnings in kernel/auditfilter.c:
Warning(kernel/auditfilter.c:1029): Excess function parameter 'loginuid' description in 'audit_receive_filter'
Warning(kernel/auditfilter.c:1029): Excess function parameter 'sessionid' description in 'audit_receive_filter'
Warning(kernel/auditfilter.c:1029): Excess function parameter 'sid' description in 'audit_receive_filter'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
result in event_enable_func(). After checking the return status
of try_module_get(), it returned the status of try_module_get(). But
try_module_get() returns 0 on failure, which is success for
event_enable_func().
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Merge tag 'trace-fixes-v3.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"Masami Hiramatsu fixed another bug. This time returning a proper
result in event_enable_func(). After checking the return status of
try_module_get(), it returned the status of try_module_get().
But try_module_get() returns 0 on failure, which is success for
event_enable_func()"
* tag 'trace-fixes-v3.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Return -EBUSY when event_enable_func() fails to get module
This patch converts cgroup_for_each_child(),
cgroup_next_descendant_pre/post() and thus
cgroup_for_each_descendant_pre/post() to use cgroup_next_sibling()
instead of manually dereferencing ->sibling.next.
The only reason the iterators couldn't allow dropping RCU read lock
while iteration is in progress was because they couldn't determine the
next sibling safely once RCU read lock is dropped. Using
cgroup_next_sibling() removes that problem and enables all iterators
to allow dropping RCU read lock in the middle. Comments are updated
accordingly.
This makes the iterators easier to use and will simplify controllers.
Note that @cgroup argument is renamed to @cgrp in
cgroup_for_each_child() because it conflicts with "struct cgroup" used
in the new macro body.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Currently, there's no easy way to find out the next sibling cgroup
unless it's known that the current cgroup is accessed from the
parent's children list in a single RCU critical section. This in turn
forces all iterators to require whole iteration to be enclosed in a
single RCU critical section, which sometimes is too restrictive. This
patch implements cgroup_next_sibling() which can reliably determine
the next sibling regardless of the state of the current cgroup as long
as it's accessible.
It currently is impossible to determine the next sibling after
dropping RCU read lock because the cgroup being iterated could be
removed anytime and if RCU read lock is dropped, nothing guarantess
its ->sibling.next pointer is accessible. A removed cgroup would
continue to point to its next sibling for RCU accesses but stop
receiving updates from the sibling. IOW, the next sibling could be
removed and then complete its grace period while RCU read lock is
dropped, making it unsafe to dereference ->sibling.next after dropping
and re-acquiring RCU read lock.
This can be solved by adding a way to traverse to the next sibling
without dereferencing ->sibling.next. This patch adds a monotonically
increasing cgroup serial number, cgroup->serial_nr, which guarantees
that all cgroup->children lists are kept in increasing serial_nr
order. A new function, cgroup_next_sibling(), is implemented, which,
if CGRP_REMOVED is not set on the current cgroup, follows
->sibling.next; otherwise, traverses the parent's ->children list
until it sees a sibling with higher ->serial_nr.
This allows the function to always return the next sibling regardless
of the state of the current cgroup without adding overhead in the fast
path.
Further patches will update the iterators to use cgroup_next_sibling()
so that they allow dropping RCU read lock and blocking while iteration
is in progress which in turn will be used to simplify controllers.
v2: Typo fix as per Serge.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
cgroup_is_removed() no longer has external users and it shouldn't grow
any - controllers should deal with cgroup_subsys_state on/offline
state instead of cgroup removal state. Make it static.
While at it, make it return bool.
Signed-off-by: Tejun Heo <tj@kernel.org>
Merging to receive 7805d000db ("cgroup: fix a subtle bug in descendant
pre-order walk") so that further iterator updates can build upon it.
Signed-off-by: Tejun Heo <tj@kernel.org>
When cgroup_next_descendant_pre() initiates a walk, it checks whether
the subtree root doesn't have any children and if not returns NULL.
Later code assumes that the subtree isn't empty. This is broken
because the subtree may become empty inbetween, which can lead to the
traversal escaping the subtree by walking to the sibling of the
subtree root.
There's no reason to have the early exit path. Remove it along with
the later assumption that the subtree isn't empty. This simplifies
the code a bit and fixes the subtle bug.
While at it, fix the comment of cgroup_for_each_descendant_pre() which
was incorrectly referring to ->css_offline() instead of
->css_online().
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: stable@vger.kernel.org
If ftrace=<tracer> is on the kernel command line, when that tracer is
registered, it will be initiated by tracing_set_tracer() to execute that
tracer.
The nop tracer is just a stub tracer that is used to have no tracer
enabled. It is assigned at early bootup as it is the default tracer.
But if ftrace=nop is on the kernel command line, the registering of the
nop tracer will call tracing_set_tracer() which will try to execute
the nop tracer. But it expects tr->current_trace to be assigned something
as it usually is assigned to the nop tracer. As it hasn't been assigned
to anything yet, it causes the system to crash.
The simple fix is to move the tr->current_trace = nop before registering
the nop tracer. The functionality is still the same as the nop tracer
doesn't do anything anyway.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
to avoid false positives (previously it was only scanning specific
sections and missing .ref.data).
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Merge tag 'kmemleak-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64
Pull kmemleak patches from Catalin Marinas:
"Kmemleak now scans all the writable and non-executable module sections
to avoid false positives (previously it was only scanning specific
sections and missing .ref.data)."
* tag 'kmemleak-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-aarch64:
kmemleak: No need for scanning specific module sections
kmemleak: Scan all allocated, writeable and not executable module sections
Christian found v3.9 does not work with E350 with EFI is enabled.
[ 1.658832] Trying to unpack rootfs image as initramfs...
[ 1.679935] BUG: unable to handle kernel paging request at ffff88006e3fd000
[ 1.686940] IP: [<ffffffff813661df>] memset+0x1f/0xb0
[ 1.692010] PGD 1f77067 PUD 1f7a067 PMD 61420067 PTE 0
but early memtest report all memory could be accessed without problem.
early page table is set in following sequence:
[ 0.000000] init_memory_mapping: [mem 0x00000000-0x000fffff]
[ 0.000000] init_memory_mapping: [mem 0x6e600000-0x6e7fffff]
[ 0.000000] init_memory_mapping: [mem 0x6c000000-0x6e5fffff]
[ 0.000000] init_memory_mapping: [mem 0x00100000-0x6bffffff]
[ 0.000000] init_memory_mapping: [mem 0x6e800000-0x6ea07fff]
but later efi_enter_virtual_mode try set mapping again wrongly.
[ 0.010644] pid_max: default: 32768 minimum: 301
[ 0.015302] init_memory_mapping: [mem 0x640c5000-0x6e3fcfff]
that means it fails with pfn_range_is_mapped.
It turns out that we have a bug in add_range_with_merge and it does not
merge range properly when new add one fill the hole between two exsiting
ranges. In the case when [mem 0x00100000-0x6bffffff] is the hole between
[mem 0x00000000-0x000fffff] and [mem 0x6c000000-0x6e7fffff].
Fix the add_range_with_merge by calling itself recursively.
Reported-by: "Christian König" <christian.koenig@amd.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/CAE9FiQVofGoSk7q5-0irjkBxemqK729cND4hov-1QCBJDhxpgQ@mail.gmail.com
Cc: <stable@vger.kernel.org> v3.9
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
As kmemleak now scans all module sections that are allocated, writable
and non executable, there's no need to scan individual sections that
might reference data.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Instead of just picking data sections by name (names that start
with .data, .bss or .ref.data), use the section flags and scan all
sections that are allocated, writable and not executable. Which should
cover all sections of a module that might reference data.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
[catalin.marinas@arm.com: removed unused 'name' variable]
[catalin.marinas@arm.com: collapsed 'if' blocks]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Pull workqueue fixes from Tejun Heo:
"Three more workqueue regression fixes.
- Fix unbalanced unlock in trylock failure path of manage_workers().
This shouldn't happen often in the wild but is possible.
- While making schedule_work() and friends inline, they become
unavailable to !GPL modules. Allow !GPL modules to access basic
stuff - system_wq and queue_*work_on() - so that schedule_work()
and friends can be used.
- During boot, the unbound NUMA support code allocates a cpumask for
each possible node using alloc_cpumask_var_node(), which ends up
trying to allocate node-specific memory even for offline nodes
triggering BUG in the memory alloc code. Use NUMA_NO_NODE for
offline nodes."
* 'for-3.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: don't perform NUMA-aware allocations on offline nodes in wq_numa_init()
workqueue: Make schedule_work() available again to non GPL modules
workqueue: correct handling of the pool spin_lock
Pull RCU fixes from Paul McKenney:
"A couple of fixes for RCU regressions:
- A boneheaded boolean-logic bug that resulted in excessive delays on
boot, hibernation and suspend that was reported by Borislav Petkov,
Bjørn Mork, and Joerg Roedel. The fix inserts a single "!".
- A fix for a boot-time splat due to allocating from bootmem too late
in boot, fix courtesy of Sasha Levin with additional help from
Yinghai Lu."
* 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
rcu: Don't allocate bootmem from rcu_init()
rcu: Fix comparison sense in rcu_needs_cpu()
argv_split(empty_or_all_spaces) happily succeeds, it simply returns
argc == 0 and argv[0] == NULL. Change call_usermodehelper_exec() to
check sub_info->path != NULL to avoid the crash.
This is the minimal fix, todo:
- perhaps we should change argv_split() to return NULL or change the
callers.
- kill or justify ->path[0] check
- narrow the scope of helper_lock()
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-By: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since try_module_get() returns false( = 0) when it fails to
pindown a module, event_enable_func() returns 0 which means
"succeed". This can cause a kernel panic when the entry
is removed, because the event is already released.
This fixes the bug by returning -EBUSY, because the reason
why it fails is that the module is being removed at that time.
Link: http://lkml.kernel.org/r/20130516114848.13508.97899.stgit@mhiramat-M0-7522
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Also, Masami Hiramatsu fixed up some minor bugs that were discovered
by sparse.
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Merge tag 'trace-fixes-v3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"This includes a fix to a memory leak when adding filters to traces.
Also, Masami Hiramatsu fixed up some minor bugs that were discovered
by sparse."
* tag 'trace-fixes-v3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/kprobes: Make print_*probe_event static
tracing/kprobes: Fix a sparse warning for incorrect type in assignment
tracing/kprobes: Use rcu_dereference_raw for tp->files
tracing: Fix leaks of filter preds
Pull perf fixes from Thomas Gleixner:
- Fix for a task exit cleanup race caused by a missing a preempt
disable
- Cleanup of the event notification functions with a massive reduction
of duplicated code
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Factor out auxiliary events notification
perf: Fix EXIT event notification
Pull timer fixes from Thomas Gleixner:
- Cure for not using zalloc in the first place, which leads to random
crashes with CPUMASK_OFF_STACK.
- Revert a user space visible change which broke udev
- Add a missing cpu_online early return introduced by the new full
dyntick conversions
- Plug a long standing race in the timer wheel cpu hotplug code.
Sigh...
- Cleanup NOHZ per cpu data on cpu down to prevent stale data on cpu
up.
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
time: Revert ALWAYS_USE_PERSISTENT_CLOCK compile time optimizaitons
timer: Don't reinitialize the cpu base lock during CPU_UP_PREPARE
tick: Don't invoke tick_nohz_stop_sched_tick() if the cpu is offline
tick: Cleanup NOHZ per cpu data on cpu down
tick: Use zalloc_cpumask_var for allocating offstack cpumasks
Pull core fixes from Thomas Gleixner:
- Two fixlets for the fallout of the generic idle task conversion
- Documentation update
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rcu/idle: Wrap cpu-idle poll mode within rcu_idle_enter/exit
idle: Fix hlt/nohlt command-line handling in new generic idle
kthread: Document ways of reducing OS jitter due to per-CPU kthreads
According to sparse warning, print_*probe_event static because
those functions are not directly called from outside.
Link: http://lkml.kernel.org/r/20130513115839.6545.83067.stgit@mhiramat-M0-7522
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Use rcu_dereference_raw() for accessing tp->files. Because the
write-side uses rcu_assign_pointer() for memory barrier,
the read-side also has to use rcu_dereference_raw() with
read memory barrier.
Link: http://lkml.kernel.org/r/20130513115834.6545.17022.stgit@mhiramat-M0-7522
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Special preds are created when folding a series of preds that
can be done in serial. These are allocated in an ops field of
the pred structure. But they were never freed, causing memory
leaks.
This was discovered using the kmemleak checker:
unreferenced object 0xffff8800797fd5e0 (size 32):
comm "swapper/0", pid 1, jiffies 4294690605 (age 104.608s)
hex dump (first 32 bytes):
00 00 01 00 03 00 05 00 07 00 09 00 0b 00 0d 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff814b52af>] kmemleak_alloc+0x73/0x98
[<ffffffff8111ff84>] kmemleak_alloc_recursive.constprop.42+0x16/0x18
[<ffffffff81120e68>] __kmalloc+0xd7/0x125
[<ffffffff810d47eb>] kcalloc.constprop.24+0x2d/0x2f
[<ffffffff810d4896>] fold_pred_tree_cb+0xa9/0xf4
[<ffffffff810d3781>] walk_pred_tree+0x47/0xcc
[<ffffffff810d5030>] replace_preds.isra.20+0x6f8/0x72f
[<ffffffff810d50b5>] create_filter+0x4e/0x8b
[<ffffffff81b1c30d>] ftrace_test_event_filter+0x5a/0x155
[<ffffffff8100028d>] do_one_initcall+0xa0/0x137
[<ffffffff81afbedf>] kernel_init_freeable+0x14d/0x1dc
[<ffffffff814b24b7>] kernel_init+0xe/0xdb
[<ffffffff814d539c>] ret_from_fork+0x7c/0xb0
[<ffffffffffffffff>] 0xffffffffffffffff
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: stable@vger.kernel.org # 2.6.39+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When rcu_init() is called we already have slab working, allocating
bootmem at that point results in warnings and an allocation from
slab. This commit therefore changes alloc_bootmem_cpumask_var() to
alloc_cpumask_var() in rcu_bootup_announce_oddness(), which is called
from rcu_init().
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Tested-by: Robin Holt <holt@sgi.com>
[paulmck: convert to zalloc_cpumask_var(), as suggested by Yinghai Lu.]
Add wait_on_atomic_t() and wake_up_atomic_t() to indicate became-zero events on
atomic_t types. This uses the bit-wake waitqueue table. The key is set to a
value outside of the number of bits in a long so that wait_on_bit() won't be
woken up accidentally.
What I'm using this for is: in a following patch I add a counter to struct
fscache_cookie to count the number of outstanding operations that need access
to netfs data. The way this works is:
(1) When a cookie is allocated, the counter is initialised to 1.
(2) When an operation wants to access netfs data, it calls atomic_inc_unless()
to increment the counter before it does so. If it was 0, then the counter
isn't incremented, the operation isn't permitted to access the netfs data
(which might by this point no longer exist) and the operation aborts in
some appropriate manner.
(3) When an operation finishes with the netfs data, it decrements the counter
and if it reaches 0, calls wake_up_atomic_t() on it - the assumption being
that it was the last blocker.
(4) When a cookie is released, the counter is decremented and the releaser
uses wait_on_atomic_t() to wait for the counter to become 0 - which should
indicate no one is using the netfs data any longer. The netfs data can
then be destroyed.
There are some alternatives that I have thought of and that have been suggested
by Tejun Heo:
(A) Using wait_on_bit() to wait on a bit in the counter. This doesn't work
because if that bit happens to be 0 then the wait won't happen - even if
the counter is non-zero.
(B) Using wait_on_bit() to wait on a flag elsewhere which is cleared when the
counter reaches 0. Such a flag would be redundant and would add
complexity.
(C) Adding a waitqueue to fscache_cookie - this would expand that struct by
several words for an event that happens just once in each cookie's
lifetime. Further, cookies are generally per-file so there are likely to
be a lot of them.
(D) Similar to (C), but add a pointer to a waitqueue in the cookie instead of
a waitqueue. This would add single word per cookie and so would be less
of an expansion - but still an expansion.
(E) Adding a static waitqueue to the fscache module. Generally this would be
fine, but under certain circumstances many cookies will all get added at
the same time (eg. NFS umount, cache withdrawal) thereby presenting
scaling issues. Note that the wait may be significant as disk I/O may be
in progress.
So, I think reusing the wait_on_bit() waitqueue set is reasonable. I don't
make much use of the waitqueue I need on a per-cookie basis, but sometimes I
have a huge flood of the cookies to deal with.
I also don't want to add a whole new set of global waitqueue tables
specifically for the dec-to-0 event if I can reuse the bit tables.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-By: Milosz Tanski <milosz@adfin.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Kay Sievers noted that the ALWAYS_USE_PERSISTENT_CLOCK config,
which enables some minor compile time optimization to avoid
uncessary code in mostly the suspend/resume path could cause
problems for userland.
In particular, the dependency for RTC_HCTOSYS on
!ALWAYS_USE_PERSISTENT_CLOCK, which avoids setting the time
twice and simplifies suspend/resume, has the side effect
of causing the /sys/class/rtc/rtcN/hctosys flag to always be
zero, and this flag is commonly used by udev to setup the
/dev/rtc symlink to /dev/rtcN, which can cause pain for
older applications.
While the udev rules could use some work to be less fragile,
breaking userland should strongly be avoided. Additionally
the compile time optimizations are fairly minor, and the code
being optimized is likely to be reworked in the future, so
lets revert this change.
Reported-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: stable <stable@vger.kernel.org> #3.9
Cc: Feng Tang <feng.tang@intel.com>
Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Link: http://lkml.kernel.org/r/1366828376-18124-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Commit 8425e3d5bd ("workqueue: inline trivial wrappers") changed
schedule_work() and schedule_delayed_work() to inline wrappers,
but these rely on some symbols that are EXPORT_SYMBOL_GPL, while
the original functions were EXPORT_SYMBOL. This has the effect of
changing the licensing requirement for these functions and making
them unavailable to non GPL modules.
Make them available again by removing the restriction on the
required symbols.
Signed-off-by: Marc Dionne <marc.dionne@your-file-system.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
When we fail to mutex_trylock(), we release the pool spin_lock and do
mutex_lock(). After that, we should regrab the pool spin_lock, but,
regrabbing is missed in current code. So correct it.
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
kdbus folks want a sane way to determine the cgroup path that a given
task belongs to on a given hierarchy, which is a reasonble thing to
expect from cgroup core.
Implement task_cgroup_path_from_hierarchy().
v2: Dropped unnecessary NULL check on the return value of
task_cgroup_from_root() as suggested by Li Zefan.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <greg@kroah.com>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Daniel Mack <daniel@zonque.org>
We want to be able to lookup a hierarchy from its id and cyclic
allocation is a whole lot simpler with idr. Convert to idr and use
idr_alloc_cyclc().
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Now that hierarchy_id alloc / free are protected by the cgroup
mutexes, there's no need for this separate lock. Drop it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
We're planning to converting hierarchy_ida to an idr and use it to
look up hierarchy from its id. As we want the mapping to happen
atomically with cgroupfs_root registration, this patch refactors
hierarchy_id init / exit so that ida operations happen inside
cgroup_[root_]mutex.
* s/init_root_id()/cgroup_init_root_id()/ and make it return 0 or
-errno like a normal function.
* Move hierarchy_id initialization from cgroup_root_from_opts() into
cgroup_mount() block where the root is confirmed to be used and
being registered while holding both mutexes.
* Split cgroup_drop_id() into cgroup_exit_root_id() and
cgroup_free_root(), so that ID release can happen before dropping
the mutexes in cgroup_kill_sb(). The latter expects hierarchy_id to
be exited before being invoked.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Commit c0f4dfd4f (rcu: Make RCU_FAST_NO_HZ take advantage of numbered
callbacks) introduced a bug that can result in excessively long grace
periods. This bug reverse the senes of the "if" statement checking
for lazy callbacks, so that RCU takes a lazy approach when there are
in fact non-lazy callbacks. This can result in excessive boot, suspend,
and resume times.
This commit therefore fixes the sense of this "if" statement.
Reported-by: Borislav Petkov <bp@alien8.de>
Reported-by: Bjørn Mork <bjorn@mork.no>
Reported-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Bjørn Mork <bjorn@mork.no>
Tested-by: Joerg Roedel <joro@8bytes.org>
This patch adds system wide workqueues aligned towards power saving. This is
done by allocating them with WQ_UNBOUND flag if 'wq_power_efficient' is set to
'true'.
tj: updated comments a bit.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Workqueues can be performance or power-oriented. Currently, most workqueues are
bound to the CPU they were created on. This gives good performance (due to cache
effects) at the cost of potentially waking up otherwise idle cores (Idle from
scheduler's perspective. Which may or may not be physically idle) just to
process some work. To save power, we can allow the work to be rescheduled on a
core that is already awake.
Workqueues created with the WQ_UNBOUND flag will allow some power savings.
However, we don't change the default behaviour of the system. To enable
power-saving behaviour, a new config option CONFIG_WQ_POWER_EFFICIENT needs to
be turned on. This option can also be overridden by the
workqueue.power_efficient boot parameter.
tj: Updated config description and comments. Renamed
CONFIG_WQ_POWER_EFFICIENT to CONFIG_WQ_POWER_EFFICIENT_DEFAULT.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Pull workqueue fix from Tejun Heo:
"A fix for a workqueue_congested() regression that broke fscache"
* 'for-3.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: workqueue_congested() shouldn't translate WORK_CPU_UNBOUND into node number
An inactive timer's base can refer to a offline cpu's base.
In the current code, cpu_base's lock is blindly reinitialized each
time a CPU is brought up. If a CPU is brought online during the period
that another thread is trying to modify an inactive timer on that CPU
with holding its timer base lock, then the lock will be reinitialized
under its feet. This leads to following SPIN_BUG().
<0> BUG: spinlock already unlocked on CPU#3, kworker/u:3/1466
<0> lock: 0xe3ebe000, .magic: dead4ead, .owner: kworker/u:3/1466, .owner_cpu: 1
<4> [<c0013dc4>] (unwind_backtrace+0x0/0x11c) from [<c026e794>] (do_raw_spin_unlock+0x40/0xcc)
<4> [<c026e794>] (do_raw_spin_unlock+0x40/0xcc) from [<c076c160>] (_raw_spin_unlock+0x8/0x30)
<4> [<c076c160>] (_raw_spin_unlock+0x8/0x30) from [<c009b858>] (mod_timer+0x294/0x310)
<4> [<c009b858>] (mod_timer+0x294/0x310) from [<c00a5e04>] (queue_delayed_work_on+0x104/0x120)
<4> [<c00a5e04>] (queue_delayed_work_on+0x104/0x120) from [<c04eae00>] (sdhci_msm_bus_voting+0x88/0x9c)
<4> [<c04eae00>] (sdhci_msm_bus_voting+0x88/0x9c) from [<c04d8780>] (sdhci_disable+0x40/0x48)
<4> [<c04d8780>] (sdhci_disable+0x40/0x48) from [<c04bf300>] (mmc_release_host+0x4c/0xb0)
<4> [<c04bf300>] (mmc_release_host+0x4c/0xb0) from [<c04c7aac>] (mmc_sd_detect+0x90/0xfc)
<4> [<c04c7aac>] (mmc_sd_detect+0x90/0xfc) from [<c04c2504>] (mmc_rescan+0x7c/0x2c4)
<4> [<c04c2504>] (mmc_rescan+0x7c/0x2c4) from [<c00a6a7c>] (process_one_work+0x27c/0x484)
<4> [<c00a6a7c>] (process_one_work+0x27c/0x484) from [<c00a6e94>] (worker_thread+0x210/0x3b0)
<4> [<c00a6e94>] (worker_thread+0x210/0x3b0) from [<c00aad9c>] (kthread+0x80/0x8c)
<4> [<c00aad9c>] (kthread+0x80/0x8c) from [<c000ea80>] (kernel_thread_exit+0x0/0x8)
As an example, this particular crash occurred when CPU #3 is executing
mod_timer() on an inactive timer whose base is refered to offlined CPU
#2. The code locked the timer_base corresponding to CPU #2. Before it
could proceed, CPU #2 came online and reinitialized the spinlock
corresponding to its base. Thus now CPU #3 held a lock which was
reinitialized. When CPU #3 finally ended up unlocking the old cpu_base
corresponding to CPU #2, we hit the above SPIN_BUG().
CPU #0 CPU #3 CPU #2
------ ------- -------
..... ...... <Offline>
mod_timer()
lock_timer_base
spin_lock_irqsave(&base->lock)
cpu_up(2) ..... ......
init_timers_cpu()
.... ..... spin_lock_init(&base->lock)
..... spin_unlock_irqrestore(&base->lock) ......
<spin_bug>
Allocation of per_cpu timer vector bases is done only once under
"tvec_base_done[]" check. In the current code, spinlock_initialization
of base->lock isn't under this check. When a CPU is up each time the
base lock is reinitialized. Move base spinlock initialization under
the check.
Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1368520142-4136-1-git-send-email-tirupath@codeaurora.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Bjørn Mork reported the following warning when running powertop.
[ 49.289034] ------------[ cut here ]------------
[ 49.289055] WARNING: at kernel/rcutree.c:502 rcu_eqs_exit_common.isra.48+0x3d/0x125()
[ 49.289244] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.10.0-bisect-rcu-warn+ #107
[ 49.289251] ffffffff8157d8c8 ffffffff81801e28 ffffffff8137e4e3 ffffffff81801e68
[ 49.289260] ffffffff8103094f ffffffff81801e68 0000000000000000 ffff88023afcd9b0
[ 49.289268] 0000000000000000 0140000000000000 ffff88023bee7700 ffffffff81801e78
[ 49.289276] Call Trace:
[ 49.289285] [<ffffffff8137e4e3>] dump_stack+0x19/0x1b
[ 49.289293] [<ffffffff8103094f>] warn_slowpath_common+0x62/0x7b
[ 49.289300] [<ffffffff8103097d>] warn_slowpath_null+0x15/0x17
[ 49.289306] [<ffffffff810a9006>] rcu_eqs_exit_common.isra.48+0x3d/0x125
[ 49.289314] [<ffffffff81079b49>] ? trace_hardirqs_off_caller+0x37/0xa6
[ 49.289320] [<ffffffff810a9692>] rcu_idle_exit+0x85/0xa8
[ 49.289327] [<ffffffff8107076e>] trace_cpu_idle_rcuidle+0xae/0xff
[ 49.289334] [<ffffffff810708b1>] cpu_startup_entry+0x72/0x115
[ 49.289341] [<ffffffff813689e5>] rest_init+0x149/0x150
[ 49.289347] [<ffffffff8136889c>] ? csum_partial_copy_generic+0x16c/0x16c
[ 49.289355] [<ffffffff81a82d34>] start_kernel+0x3f0/0x3fd
[ 49.289362] [<ffffffff81a8274c>] ? repair_env_string+0x5a/0x5a
[ 49.289368] [<ffffffff81a82481>] x86_64_start_reservations+0x2a/0x2c
[ 49.289375] [<ffffffff81a82550>] x86_64_start_kernel+0xcd/0xd1
[ 49.289379] ---[ end trace 07a1cc95e29e9036 ]---
The warning is that 'rdtp->dynticks' has an unexpected value, which roughly
translates to - the calls to rcu_idle_enter() and rcu_idle_exit() were not
made in the correct order, or otherwise messed up.
And Bjørn's painstaking debugging indicated that this happens when the idle
loop enters the poll mode. Looking at the poll function cpu_idle_poll(), and
the implementation of trace_cpu_idle_rcuidle(), the problem becomes very clear:
cpu_idle_poll() lacks calls to rcu_idle_enter/exit(), and trace_cpu_idle_rcuidle()
calls them in the reverse order - first rcu_idle_exit(), and then rcu_idle_enter().
Hence the even/odd alternative sequencing of rdtp->dynticks goes for a toss.
And powertop readily triggers this because powertop uses the idle-tracing
infrastructure extensively.
So, to fix this, wrap the code in cpu_idle_poll() within rcu_idle_enter/exit(),
so that it blends properly with the calls inside trace_cpu_idle_rcuidle() and
thus get the function ordering right.
Reported-and-tested-by: Bjørn Mork <bjorn@mork.no>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/519169BF.4080208@linux.vnet.ibm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
commit 5b39939a4 (nohz: Move ts->idle_calls incrementation into strict
idle logic) moved code out of tick_nohz_stop_sched_tick() and missed
to bail out when the cpu is offline. That's causing subsequent
failures as an offline CPU is supposed to die and not to fiddle with
nohz magic.
Return false in can_stop_idle_tick() if the cpu is offline.
Reported-and-tested-by: Jiri Kosina <jkosina@suse.cz>
Reported-and-tested-by: Prarit Bhargava <prarit@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1305132138160.2863@ionos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
cgroup_create_file() calls d_instantiate(), which may decide to look
at the xattrs on the file. Smack always does this and SELinux can be
configured to do so.
But cgroup_add_file() didn't initialize xattrs before calling
cgroup_create_file(), which finally leads to dereferencing NULL
dentry->d_fsdata.
This bug has been there since cgroup xattr was introduced.
Cc: <stable@vger.kernel.org> # 3.8.x
Reported-by: Ivan Bulatovic <combuster@archlinux.us>
Reported-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Avoid waking up every thread sleeping in a sigtimedwait call during
suspend and resume by calling a freezable blocking call. Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.
This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Avoid waking up every thread sleeping in a nanosleep call during
suspend and resume by calling a freezable blocking call. Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.
This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Avoid waking up every thread sleeping in a futex_wait call during
suspend and resume by calling a freezable blocking call. Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.
This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Android goes through suspend/resume very often (every few seconds when
on a busy wifi network with the screen off), and a significant portion
of the energy used to go in and out of suspend is spent in the
freezer. If a task has called freezer_do_not_count(), don't bother
waking it up. If it happens to wake up later it will call
freezer_count() and immediately enter the refrigerator.
Combined with patches to convert freezable helpers to use
freezer_do_not_count() and convert common sites where idle userspace
tasks are blocked to use the freezable helpers, this reduces the
time and energy required to suspend and resume.
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
All tasks can easily be frozen in under 10 ms, switch to using
an initial 1 ms sleep followed by exponential backoff until
8 ms. Also convert the printed time to ms instead of centiseconds.
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The only existing caller to debug_check_no_locks_held calls it
with 'current' as the task, and the freezer needs to call
debug_check_no_locks_held but doesn't already have a current
task pointer, so remove the argument. It is already assuming
that the current task is relevant by dumping the current stack
trace as part of the warning.
This was originally part of 6aa9707099 (lockdep: check that
no locks held at freeze time) which was reverted in
dbf520a9d7.
Original-author: Mandeep Singh Baines <msb@chromium.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Prarit reported a crash on CPU offline/online. The reason is that on
CPU down the NOHZ related per cpu data of the dead cpu is not cleaned
up. If at cpu online an interrupt happens before the per cpu tick
device is registered the irq_enter() check potentially sees stale data
and dereferences a NULL pointer.
Cleanup the data after the cpu is dead.
Reported-by: Prarit Bhargava <prarit@redhat.com>
Cc: stable@vger.kernel.org
Cc: Mike Galbraith <bitbucket@online.de>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1305031451561.2886@ionos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
kprobes up to par with the latest changes to ftrace (multi buffering
and the new function probes).
He also discovered and fixed some bugs in doing so. When pulling in his
patches, I also found a few minor bugs as well and fixed them.
This also includes a compile fix for some archs that select the ring buffer
but not tracing.
I based this off of the last patch you took from me that fixed the merge
conflict error, as that was the commit that had all the changes I needed
for this set of changes.
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Merge tag 'trace-fixes-v3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing/kprobes update from Steven Rostedt:
"The majority of these changes are from Masami Hiramatsu bringing
kprobes up to par with the latest changes to ftrace (multi buffering
and the new function probes).
He also discovered and fixed some bugs in doing so. When pulling in
his patches, I also found a few minor bugs as well and fixed them.
This also includes a compile fix for some archs that select the ring
buffer but not tracing.
I based this off of the last patch you took from me that fixed the
merge conflict error, as that was the commit that had all the changes
I needed for this set of changes."
* tag 'trace-fixes-v3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/kprobes: Support soft-mode disabling
tracing/kprobes: Support ftrace_event_file base multibuffer
tracing/kprobes: Pass trace_probe directly from dispatcher
tracing/kprobes: Increment probe hit-count even if it is used by perf
tracing/kprobes: Use bool for retprobe checker
ftrace: Fix function probe when more than one probe is added
ftrace: Fix the output of enabled_functions debug file
ftrace: Fix locking in register_ftrace_function_probe()
tracing: Add helper function trace_create_new_event() to remove duplicate code
tracing: Modify soft-mode only if there's no other referrer
tracing: Indicate enabled soft-mode in enable file
tracing/kprobes: Fix to increment return event probe hit-count
ftrace: Cleanup regex_lock and ftrace_lock around hash updating
ftrace, kprobes: Fix a deadlock on ftrace_regex_lock
ftrace: Have ftrace_regex_write() return either read or error
tracing: Return error if register_ftrace_function_probe() fails for event_enable_func()
tracing: Don't succeed if event_enable_func did not register anything
ring-buffer: Select IRQ_WORK
Pull audit changes from Eric Paris:
"Al used to send pull requests every couple of years but he told me to
just start pushing them to you directly.
Our touching outside of core audit code is pretty straight forward. A
couple of interface changes which hit net/. A simple argument bug
calling audit functions in namei.c and the removal of some assembly
branch prediction code on ppc"
* git://git.infradead.org/users/eparis/audit: (31 commits)
audit: fix message spacing printing auid
Revert "audit: move kaudit thread start from auditd registration to kaudit init"
audit: vfs: fix audit_inode call in O_CREAT case of do_last
audit: Make testing for a valid loginuid explicit.
audit: fix event coverage of AUDIT_ANOM_LINK
audit: use spin_lock in audit_receive_msg to process tty logging
audit: do not needlessly take a lock in tty_audit_exit
audit: do not needlessly take a spinlock in copy_signal
audit: add an option to control logging of passwords with pam_tty_audit
audit: use spin_lock_irqsave/restore in audit tty code
helper for some session id stuff
audit: use a consistent audit helper to log lsm information
audit: push loginuid and sessionid processing down
audit: stop pushing loginid, uid, sessionid as arguments
audit: remove the old depricated kernel interface
audit: make validity checking generic
audit: allow checking the type of audit message in the user filter
audit: fix build break when AUDIT_DEBUG == 2
audit: remove duplicate export of audit_enabled
Audit: do not print error when LSMs disabled
...
Pull stray syscall bits from Al Viro:
"Several syscall-related commits that were missing from the original"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
switch compat_sys_sysctl to COMPAT_SYSCALL_DEFINE
unicore32: just use mmap_pgoff()...
unify compat fanotify_mark(2), switch to COMPAT_SYSCALL_DEFINE
x86, vm86: fix VM86 syscalls: use SYSCALL_DEFINEx(...)
- Two krealloc() abuse fixes
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Merge tag 'for-linus-20130509' of git://git.infradead.org/~dwmw2/random-2.6
Pull misc fixes from David Woodhouse:
"This is some miscellaneous cleanups that don't really belong anywhere
else (or were ignored), that have been sitting in linux-next for some
time. Two of them are fixes resulting from my audit of krealloc()
usage that don't seem to have elicited any response when I posted
them, and the other three are patches from Artem removing dead code."
* tag 'for-linus-20130509' of git://git.infradead.org/~dwmw2/random-2.6:
pcmcia: remove RPX board stuff
m68k: remove rpxlite stuff
pcmcia: remove Motorola MBX860 support
params: Fix potential memory leak in add_sysfs_param()
dell-laptop: Fix krealloc() misuse in parse_da_table()
It is a few instructions more efficent to and slightly more
readable to use this_rq()-> instead of cpu_rq(smp_processor_id())-> .
Size comparison of kernel/sched/fair.o:
text data bss dec hex filename
27972 122 26 28120 6dd8 fair.o.before
27956 122 26 28104 6dc8 fair.o.after
Signed-off-by: Nathan Zimmer <nzimmer@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1368116643-87971-1-git-send-email-nzimmer@sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Support soft-mode disabling on kprobe-based dynamic events.
Soft-disabling is just ignoring recording if the soft disabled
flag is set.
Link: http://lkml.kernel.org/r/20130509054454.30398.7237.stgit@mhiramat-M0-7522
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Increment probe hit-count for profiling even if it is used
by perf tool. Same thing has already done in trace_uprobe.
Link: http://lkml.kernel.org/r/20130509054436.30398.21133.stgit@mhiramat-M0-7522
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The enabled_functions debugfs file was created to be able to see
what functions have been modified from nops to calling a tracer.
The current method uses the counter in the function record.
As when a ftrace_ops is registered to a function, its count
increases. But that doesn't mean that the function is actively
being traced. /proc/sys/kernel/ftrace_enabled can be set to zero
which would disable it, as well as something can go wrong and
we can think its enabled when only the counter is set.
The record's FTRACE_FL_ENABLED flag is set or cleared when its
function is modified. That is a much more accurate way of knowing
what function is enabled or not.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The iteration of the ftrace function list and the call to
ftrace_match_record() need to be protected by the ftrace_lock.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Both __trace_add_new_event() and __trace_early_add_new_event() do
basically the same thing, except that __trace_add_new_event() does
a little more.
Instead of having duplicate code between the two functions, add
a helper function trace_create_new_event() that both can use.
This will help against having bugs fixed in one function but not
the other.
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Modify soft-mode flag only if no other soft-mode referrer
(currently only the ftrace triggers) by using a reference
counter in each ftrace_event_file.
Without this fix, adding and removing several different
enable/disable_event triggers on the same event clear
soft-mode bit from the ftrace_event_file. This also
happens with a typo of glob on setting triggers.
e.g.
# echo vfs_symlink:enable_event:net:netif_rx > set_ftrace_filter
# cat events/net/netif_rx/enable
0*
# echo typo_func:enable_event:net:netif_rx > set_ftrace_filter
# cat events/net/netif_rx/enable
0
# cat set_ftrace_filter
#### all functions enabled ####
vfs_symlink:enable_event:net:netif_rx:unlimited
As above, we still have a trigger, but soft-mode is gone.
Link: http://lkml.kernel.org/r/20130509054429.30398.7464.stgit@mhiramat-M0-7522
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: David Sharp <dhsharp@google.com>
Cc: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Indicate enabled soft-mode event as "1*" in "enable" file
for each event, because it can be soft-disabled when disable_event
trigger is hit.
Link: http://lkml.kernel.org/r/20130509054426.30398.28202.stgit@mhiramat-M0-7522
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cleanup regex_lock and ftrace_lock locking points around
ftrace_ops hash update code.
The new rule is that regex_lock protects ops->*_hash
read-update-write code for each ftrace_ops. Usually,
hash update is done by following sequence.
1. allocate a new local hash and copy the original hash.
2. update the local hash.
3. move(actually, copy) back the local hash to ftrace_ops.
4. update ftrace entries if needed.
5. release the local hash.
This makes regex_lock protect #1-#4, and ftrace_lock
to protect #3, #4 and adding and removing ftrace_ops from the
ftrace_ops_list. The ftrace_lock protects #3 as well because
the move functions update the entries too.
Link: http://lkml.kernel.org/r/20130509054421.30398.83411.stgit@mhiramat-M0-7522
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Fix a deadlock on ftrace_regex_lock which happens when setting
an enable_event trigger on dynamic kprobe event as below.
----
sh-2.05b# echo p vfs_symlink > kprobe_events
sh-2.05b# echo vfs_symlink:enable_event:kprobes:p_vfs_symlink_0 > set_ftrace_filter
=============================================
[ INFO: possible recursive locking detected ]
3.9.0+ #35 Not tainted
---------------------------------------------
sh/72 is trying to acquire lock:
(ftrace_regex_lock){+.+.+.}, at: [<ffffffff810ba6c1>] ftrace_set_hash+0x81/0x1f0
but task is already holding lock:
(ftrace_regex_lock){+.+.+.}, at: [<ffffffff810b7cbd>] ftrace_regex_write.isra.29.part.30+0x3d/0x220
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(ftrace_regex_lock);
lock(ftrace_regex_lock);
*** DEADLOCK ***
----
To fix that, this introduces a finer regex_lock for each ftrace_ops.
ftrace_regex_lock is too big of a lock which protects all
filter/notrace_hash operations, but it doesn't need to be a global
lock after supporting multiple ftrace_ops because each ftrace_ops
has its own filter/notrace_hash.
Link: http://lkml.kernel.org/r/20130509054417.30398.84254.stgit@mhiramat-M0-7522
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
[ Added initialization flag and automate mutex initialization for
non ftrace.c ftrace_probes. ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
As ftrace_regex_write() reads the result of ftrace_process_regex()
which can sometimes return a positive number, only consider a
failure if the return is negative. Otherwise, it will skip possible
other registered probes and by returning a positive number that
wasn't read, it will confuse the user processes doing the writing.
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
register_ftrace_function_probe() returns the number of functions
it registered, which can be zero, it can also return a negative number
if something went wrong. But event_enable_func() only checks for
the case that it didn't register anything, it needs to also check
for the case that something went wrong and return that error code
as well.
Added some comments about the code as well, to make it more
understandable.
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Return 0 instead of the number of activated ftrace function probes if
event_enable_func succeeded and return an error code if it failed or
did not register any functions. But it currently returns the number
of registered functions and if it didn't register anything, it returns 0,
but that is considered success.
This also fixes the return value. As if it succeeds, it returns the
number of functions that were enabled, which is returned back to
the user in ftrace_regex_write (the write() return code). If only
one function is enabled, then the return code of the write is one,
and this can confuse the user program in thinking it only wrote 1
byte.
Link: http://lkml.kernel.org/r/20130509054413.30398.55650.stgit@mhiramat-M0-7522
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
[ Rewrote change log to reflect that this fixes two bugs - SR ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull block driver updates from Jens Axboe:
"It might look big in volume, but when categorized, not a lot of
drivers are touched. The pull request contains:
- mtip32xx fixes from Micron.
- A slew of drbd updates, this time in a nicer series.
- bcache, a flash/ssd caching framework from Kent.
- Fixes for cciss"
* 'for-3.10/drivers' of git://git.kernel.dk/linux-block: (66 commits)
bcache: Use bd_link_disk_holder()
bcache: Allocator cleanup/fixes
cciss: bug fix to prevent cciss from loading in kdump crash kernel
cciss: add cciss_allow_hpsa module parameter
drivers/block/mg_disk.c: add CONFIG_PM_SLEEP to suspend/resume functions
mtip32xx: Workaround for unaligned writes
bcache: Make sure blocksize isn't smaller than device blocksize
bcache: Fix merge_bvec_fn usage for when it modifies the bvm
bcache: Correctly check against BIO_MAX_PAGES
bcache: Hack around stuff that clones up to bi_max_vecs
bcache: Set ra_pages based on backing device's ra_pages
bcache: Take data offset from the bdev superblock.
mtip32xx: mtip32xx: Disable TRIM support
mtip32xx: fix a smatch warning
bcache: Disable broken btree fuzz tester
bcache: Fix a format string overflow
bcache: Fix a minor memory leak on device teardown
bcache: Documentation updates
bcache: Use WARN_ONCE() instead of __WARN()
bcache: Add missing #include <linux/prefetch.h>
...
Pull block core updates from Jens Axboe:
- Major bit is Kents prep work for immutable bio vecs.
- Stable candidate fix for a scheduling-while-atomic in the queue
bypass operation.
- Fix for the hang on exceeded rq->datalen 32-bit unsigned when merging
discard bios.
- Tejuns changes to convert the writeback thread pool to the generic
workqueue mechanism.
- Runtime PM framework, SCSI patches exists on top of these in James'
tree.
- A few random fixes.
* 'for-3.10/core' of git://git.kernel.dk/linux-block: (40 commits)
relay: move remove_buf_file inside relay_close_buf
partitions/efi.c: replace useless kzalloc's by kmalloc's
fs/block_dev.c: fix iov_shorten() criteria in blkdev_aio_read()
block: fix max discard sectors limit
blkcg: fix "scheduling while atomic" in blk_queue_bypass_start
Documentation: cfq-iosched: update documentation help for cfq tunables
writeback: expose the bdi_wq workqueue
writeback: replace custom worker pool implementation with unbound workqueue
writeback: remove unused bdi_pending_list
aoe: Fix unitialized var usage
bio-integrity: Add explicit field for owner of bip_buf
block: Add an explicit bio flag for bios that own their bvec
block: Add bio_alloc_pages()
block: Convert some code to bio_for_each_segment_all()
block: Add bio_for_each_segment_all()
bounce: Refactor __blk_queue_bounce to not use bi_io_vec
raid1: use bio_copy_data()
pktcdvd: Use bio_reset() in disabled code to kill bi_idx usage
pktcdvd: use bio_copy_data()
block: Add bio_copy_data()
...
The helper function didn't include a leading space, so it was jammed
against the previous text in the audit record.
Signed-off-by: Eric Paris <eparis@redhat.com>
Merge more incoming from Andrew Morton:
- Various fixes which were stalled or which I picked up recently
- A large rotorooting of the AIO code. Allegedly to improve
performance but I don't really have good performance numbers (I might
have lost the email) and I can't raise Kent today. I held this out
of 3.9 and we could give it another cycle if it's all too late/scary.
I ended up taking only the first two thirds of the AIO rotorooting. I
left the percpu parts and the batch completion for later. - Linus
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (33 commits)
aio: don't include aio.h in sched.h
aio: kill ki_retry
aio: kill ki_key
aio: give shared kioctx fields their own cachelines
aio: kill struct aio_ring_info
aio: kill batch allocation
aio: change reqs_active to include unreaped completions
aio: use cancellation list lazily
aio: use flush_dcache_page()
aio: make aio_read_evt() more efficient, convert to hrtimers
wait: add wait_event_hrtimeout()
aio: refcounting cleanup
aio: make aio_put_req() lockless
aio: do fget() after aio_get_req()
aio: dprintk() -> pr_debug()
aio: move private stuff out of aio.h
aio: add kiocb_cancel()
aio: kill return value of aio_complete()
char: add aio_{read,write} to /dev/{null,zero}
aio: remove retry-based AIO
...
This reverts commit 6ff5e45985.
Conflicts:
kernel/audit.c
This patch was starting a kthread for all the time. Since the follow on
patches that required it didn't get finished in 3.10 time, we shouldn't
ship this change in 3.10.
Signed-off-by: Eric Paris <eparis@redhat.com>
audit rule additions containing "-F auid!=4294967295" were failing
with EINVAL because of a regression caused by e1760bd.
Apparently some userland audit rule sets want to know if loginuid uid
has been set and are using a test for auid != 4294967295 to determine
that.
In practice that is a horrible way to ask if a value has been set,
because it relies on subtle implementation details and will break
every time the uid implementation in the kernel changes.
So add a clean way to test if the audit loginuid has been set, and
silently convert the old idiom to the cleaner and more comprehensible
new idiom.
Cc: <stable@vger.kernel.org> # 3.7
Reported-By: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Tested-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Add perf_event_aux() function to send out all types of
auxiliary events - mmap, task, comm events. For each type
there's match and output functions defined and used as
callbacks during perf_event_aux processing.
This way we can centralize the pmu/context iterating and
event matching logic. Also since lot of the code was
duplicated, this patch reduces the .text size about 2kB
on my setup:
snipped output from 'objdump -x kernel/events/core.o'
before:
Idx Name Size
0 .text 0000d313
after:
Idx Name Size
0 .text 0000cad3
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/1367857638-27631-3-git-send-email-jolsa@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The perf_event_task_ctx() function needs to be called with
preemption disabled, since it's checking for currently
scheduled cpu against event cpu.
We disable preemption for task related perf event context
if there's one defined, leaving up to the chance which cpu
it gets scheduled in.
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/1367857638-27631-2-git-send-email-jolsa@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
These inlines are only used by kernel/sched/fair.c so they do
not need to be present in the main kernel/sched/sched.h file.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1366398650-31599-3-git-send-email-paul.gortmaker@windriver.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This large chunk of load calculation code can be easily divorced
from the main core.c scheduler file, with only a couple
prototypes and externs added to a kernel/sched header.
Some recent commits expanded the code and the documentation of
it, making it large enough to warrant separation. For example,
see:
556061b, "sched/nohz: Fix rq->cpu_load[] calculations"
5aaa0b7, "sched/nohz: Fix rq->cpu_load calculations some more"
5167e8d, "sched/nohz: Rewrite and fix load-avg computation -- again"
More importantly, it helps reduce the size of the main
sched/core.c by yet another significant amount (~600 lines).
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1366398650-31599-2-git-send-email-paul.gortmaker@windriver.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Some interrupt controllers refuse to map interrupts marked as
"protected" by firwmare. Since we try to map everyting in the
device-tree on some platforms, we end up with a lot of nasty
WARN's in the boot log for what is a normal situation on those
machines.
This defines a specific return code (-EPERM) from the host map()
callback which cause irqdomain to fail silently.
MPIC is updated to return this when hitting a protected source
printing only a single line message for diagnostic purposes.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Pull 'full dynticks' support from Ingo Molnar:
"This tree from Frederic Weisbecker adds a new, (exciting! :-) core
kernel feature to the timer and scheduler subsystems: 'full dynticks',
or CONFIG_NO_HZ_FULL=y.
This feature extends the nohz variable-size timer tick feature from
idle to busy CPUs (running at most one task) as well, potentially
reducing the number of timer interrupts significantly.
This feature got motivated by real-time folks and the -rt tree, but
the general utility and motivation of full-dynticks runs wider than
that:
- HPC workloads get faster: CPUs running a single task should be able
to utilize a maximum amount of CPU power. A periodic timer tick at
HZ=1000 can cause a constant overhead of up to 1.0%. This feature
removes that overhead - and speeds up the system by 0.5%-1.0% on
typical distro configs even on modern systems.
- Real-time workload latency reduction: CPUs running critical tasks
should experience as little jitter as possible. The last remaining
source of kernel-related jitter was the periodic timer tick.
- A single task executing on a CPU is a pretty common situation,
especially with an increasing number of cores/CPUs, so this feature
helps desktop and mobile workloads as well.
The cost of the feature is mainly related to increased timer
reprogramming overhead when a CPU switches its tick period, and thus
slightly longer to-idle and from-idle latency.
Configuration-wise a third mode of operation is added to the existing
two NOHZ kconfig modes:
- CONFIG_HZ_PERIODIC: [formerly !CONFIG_NO_HZ], now explicitly named
as a config option. This is the traditional Linux periodic tick
design: there's a HZ tick going on all the time, regardless of
whether a CPU is idle or not.
- CONFIG_NO_HZ_IDLE: [formerly CONFIG_NO_HZ=y], this turns off the
periodic tick when a CPU enters idle mode.
- CONFIG_NO_HZ_FULL: this new mode, in addition to turning off the
tick when a CPU is idle, also slows the tick down to 1 Hz (one
timer interrupt per second) when only a single task is running on a
CPU.
The .config behavior is compatible: existing !CONFIG_NO_HZ and
CONFIG_NO_HZ=y settings get translated to the new values, without the
user having to configure anything. CONFIG_NO_HZ_FULL is turned off by
default.
This feature is based on a lot of infrastructure work that has been
steadily going upstream in the last 2-3 cycles: related RCU support
and non-periodic cputime support in particular is upstream already.
This tree adds the final pieces and activates the feature. The pull
request is marked RFC because:
- it's marked 64-bit only at the moment - the 32-bit support patch is
small but did not get ready in time.
- it has a number of fresh commits that came in after the merge
window. The overwhelming majority of commits are from before the
merge window, but still some aspects of the tree are fresh and so I
marked it RFC.
- it's a pretty wide-reaching feature with lots of effects - and
while the components have been in testing for some time, the full
combination is still not very widely used. That it's default-off
should reduce its regression abilities and obviously there are no
known regressions with CONFIG_NO_HZ_FULL=y enabled either.
- the feature is not completely idempotent: there is no 100%
equivalent replacement for a periodic scheduler/timer tick. In
particular there's ongoing work to map out and reduce its effects
on scheduler load-balancing and statistics. This should not impact
correctness though, there are no known regressions related to this
feature at this point.
- it's a pretty ambitious feature that with time will likely be
enabled by most Linux distros, and we'd like you to make input on
its design/implementation, if you dislike some aspect we missed.
Without flaming us to crisp! :-)
Future plans:
- there's ongoing work to reduce 1Hz to 0Hz, to essentially shut off
the periodic tick altogether when there's a single busy task on a
CPU. We'd first like 1 Hz to be exposed more widely before we go
for the 0 Hz target though.
- once we reach 0 Hz we can remove the periodic tick assumption from
nr_running>=2 as well, by essentially interrupting busy tasks only
as frequently as the sched_latency constraints require us to do -
once every 4-40 msecs, depending on nr_running.
I am personally leaning towards biting the bullet and doing this in
v3.10, like the -rt tree this effort has been going on for too long -
but the final word is up to you as usual.
More technical details can be found in Documentation/timers/NO_HZ.txt"
* 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (39 commits)
sched: Keep at least 1 tick per second for active dynticks tasks
rcu: Fix full dynticks' dependency on wide RCU nocb mode
nohz: Protect smp_processor_id() in tick_nohz_task_switch()
nohz_full: Add documentation.
cputime_nsecs: use math64.h for nsec resolution conversion helpers
nohz: Select VIRT_CPU_ACCOUNTING_GEN from full dynticks config
nohz: Reduce overhead under high-freq idling patterns
nohz: Remove full dynticks' superfluous dependency on RCU tree
nohz: Fix unavailable tick_stop tracepoint in dynticks idle
nohz: Add basic tracing
nohz: Select wide RCU nocb for full dynticks
nohz: Disable the tick when irq resume in full dynticks CPU
nohz: Re-evaluate the tick for the new task after a context switch
nohz: Prepare to stop the tick on irq exit
nohz: Implement full dynticks kick
nohz: Re-evaluate the tick from the scheduler IPI
sched: New helper to prevent from stopping the tick in full dynticks
sched: Kick full dynticks CPU that have more than one task enqueued.
perf: New helper to prevent full dynticks CPUs from stopping tick
perf: Kick full dynticks CPU if events rotation is needed
...
Pull perf fixes from Ingo Molnar:
"Misc fixes plus a small hw-enablement patch for Intel IB model 58
uncore events"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel/lbr: Demand proper privileges for PERF_SAMPLE_BRANCH_KERNEL
perf/x86/intel/lbr: Fix LBR filter
perf/x86: Blacklist all MEM_*_RETIRED events for Ivy Bridge
perf: Fix vmalloc ring buffer pages handling
perf/x86/intel: Fix unintended variable name reuse
perf/x86/intel: Add support for IvyBridge model 58 Uncore
perf/x86/intel: Fix typo in perf_event_intel_uncore.c
x86: Eliminate irq_mis_count counted in arch_irq_stat
fix a remove/insert race which Never Happens, and (my favorite) handle the
case when we have too many modules for a single commandline. Seriously,
the kernel is full, please go away!
Cheers,
Rusty.
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Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull mudule updates from Rusty Russell:
"We get rid of the general module prefix confusion with a binary config
option, fix a remove/insert race which Never Happens, and (my
favorite) handle the case when we have too many modules for a single
commandline. Seriously, the kernel is full, please go away!"
* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
modpost: fix unwanted VMLINUX_SYMBOL_STR expansion
X.509: Support parse long form of length octets in Authority Key Identifier
module: don't unlink the module until we've removed all exposure.
kernel: kallsyms: memory override issue, need check destination buffer length
MODSIGN: do not send garbage to stderr when enabling modules signature
modpost: handle huge numbers of modules.
modpost: add -T option to read module names from file/stdin.
modpost: minor cleanup.
genksyms: pass symbol-prefix instead of arch
module: fix symbol versioning with symbol prefixes
CONFIG_SYMBOL_PREFIX: cleanup.
commit b352bc1cbc (tick: Convert broadcast cpu bitmaps to
cpumask_var_t) broke CONFIG_CPUMASK_OFFSTACK in a very subtle way.
Instead of allocating the cpumasks with zalloc_cpumask_var it uses
alloc_cpumask_var, so we can get random data there, which of course
confuses the logic completely and causes random failures.
Reported-and-tested-by: Dave Jones <davej@redhat.com>
Reported-and-tested-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1305032015060.2990@ionos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull second round of VFS updates from Al Viro:
"Assorted fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
xtensa simdisk: fix braino in "xtensa simdisk: switch to proc_create_data()"
hostfs: use kmalloc instead of kzalloc
hostfs: move HOSTFS_SUPER_MAGIC to <linux/magic.h>
hostfs: remove "will unlock" comment
vfs: use list_move instead of list_del/list_add
proc_devtree: Replace include linux/module.h with linux/export.h
create_mnt_ns: unidiomatic use of list_add()
fs: remove dentry_lru_prune()
Removed unused typedef to avoid "unused local typedef" warnings.
kill fs/read_write.h
fs: Fix hang with BSD accounting on frozen filesystem
sun3_scsi: add ->show_info()
nubus: Kill nubus_proc_detach_device()
more mode_t whack-a-mole...
do_coredump(): don't wait for thaw if coredump has already been interrupted
do_mount(): fix a leak introduced in 3.9 ("mount: consolidate permission checks")
When BSD process accounting is enabled and logs information to a
filesystem which gets frozen, system easily becomes unusable because
each attempt to account process information blocks. Thus e.g. every task
gets blocked in exit.
It seems better to drop accounting information (which can already happen
when filesystem is running out of space) instead of locking system up.
So we just skip the write if the filesystem is frozen.
Reported-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
