Commit Graph

10685 Commits

Author SHA1 Message Date
Steven Rostedt
13b9b6e746 tracing: Fix module use of trace_bprintk()
On use of trace_printk() there's a macro that determines if the format
is static or a variable. If it is static, it defaults to __trace_bprintk()
otherwise it uses __trace_printk().

A while ago, Lai Jiangshan added __trace_bprintk(). In that patch, we
discussed a way to allow modules to use it. The difference between
__trace_bprintk() and __trace_printk() is that for faster processing,
just the format and args are stored in the trace instead of running
it through a sprintf function. In order to do this, the format used
by the __trace_bprintk() had to be persistent.

See commit 1ba28e02a1

The problem comes with trace_bprintk() where the module is unloaded.
The pointer left in the buffer is still pointing to the format.

To solve this issue, the formats in the module were copied into kernel
core. If the same format was used, they would use the same copy (to prevent
memory leak). This all worked well until we tried to merge everything.

At the time this was written, Lai Jiangshan, Frederic Weisbecker,
Ingo Molnar and myself were all touching the same code. When this was
merged, we lost the part of it that was in module.c. This kept out the
copying of the formats and unloading the module could cause bad pointers
left in the ring buffer.

This patch adds back (with updates required for current kernel) the
module code that sets up the necessary pointers.

Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-11-10 22:19:24 -05:00
Mark Brown
43e60861fe PM / OPP: Hide OPP configuration when SoCs do not provide an implementation
Since the OPP API is only useful with an appropraite SoC-specific
implementation there is no point in offering the ability to enable
the API on general systems. Provide an ARCH_HAS OPP Kconfig symbol
which masks out the option unless selected by an implementation.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Nishanth Menon <nm@ti.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-11-11 01:51:26 +01:00
Peter Zijlstra
2d46709082 sched: Fix runnable condition for stoptask
Heiko reported that the TASK_RUNNING check is not sufficient for
CONFIG_PREEMPT=y since we can get preempted with !TASK_RUNNING.

He suggested adding a ->se.on_rq test to the existing TASK_RUNNING
one, however TASK_RUNNING will always have ->se.on_rq, so we might as
well reduce that to a single test.

[ stop tasks should never get preempted, but its good to handle
  this case correctly should this ever happen ]

Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-10 23:13:58 +01:00
Suresh Siddha
aae6d3ddd8 sched: Use group weight, idle cpu metrics to fix imbalances during idle
Currently we consider a sched domain to be well balanced when the imbalance
is less than the domain's imablance_pct. As the number of cores and threads
are increasing, current values of imbalance_pct (for example 25% for a
NUMA domain) are not enough to detect imbalances like:

a) On a WSM-EP system (two sockets, each having 6 cores and 12 logical threads),
24 cpu-hogging tasks get scheduled as 13 on one socket and 11 on another
socket. Leading to an idle HT cpu.

b) On a hypothetial 2 socket NHM-EX system (each socket having 8 cores and
16 logical threads), 16 cpu-hogging tasks can get scheduled as 9 on one
socket and 7 on another socket. Leaving one core in a socket idle
whereas in another socket we have a core having both its HT siblings busy.

While this issue can be fixed by decreasing the domain's imbalance_pct
(by making it a function of number of logical cpus in the domain), it
can potentially cause more task migrations across sched groups in an
overloaded case.

Fix this by using imbalance_pct only during newly_idle and busy
load balancing. And during idle load balancing, check if there
is an imbalance in number of idle cpu's across the busiest and this
sched_group or if the busiest group has more tasks than its weight that
the idle cpu in this_group can pull.

Reported-by: Nikhil Rao <ncrao@google.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1284760952.2676.11.camel@sbsiddha-MOBL3.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-10 23:13:56 +01:00
Stephane Eranian
eed01528a4 perf_events: Fix time tracking in samples
This patch corrects time tracking in samples. Without this patch
both time_enabled and time_running are bogus when user asks for
PERF_SAMPLE_READ.

One uses PERF_SAMPLE_READ to sample the values of other counters
in each sample. Because of multiplexing, it is necessary to know
both time_enabled, time_running to be able to scale counts correctly.

In this second version of the patch, we maintain a shadow
copy of ctx->time which allows us to compute ctx->time without
calling update_context_time() from NMI context. We avoid the
issue that update_context_time() must always be called with
ctx->lock held.

We do not keep shadow copies of the other event timings
because if the lead event is overflowing then it is active
and thus it's been scheduled in via event_sched_in() in
which case neither tstamp_stopped, tstamp_running can be modified.

This timing logic only applies to samples when PERF_SAMPLE_READ
is used.

Note that this patch does not address timing issues related
to sampling inheritance between tasks. This will be addressed
in a future patch.

With this patch, the libpfm4 example task_smpl now reports
correct counts (shown on 2.4GHz Core 2):

$ task_smpl -p 2400000000 -e unhalted_core_cycles:u,instructions_retired:u,baclears  noploop 5
noploop for 5 seconds
IIP:0x000000004006d6 PID:5596 TID:5596 TIME:466,210,211,430 STREAM_ID:33 PERIOD:2,400,000,000 ENA=1,010,157,814 RUN=1,010,157,814 NR=3
	2,400,000,254 unhalted_core_cycles:u (33)
	2,399,273,744 instructions_retired:u (34)
	53,340 baclears (35)

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4cc6e14b.1e07e30a.256e.5190@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-10 22:58:39 +01:00
Christoph Hellwig
02e031cbc8 block: remove REQ_HARDBARRIER
REQ_HARDBARRIER is dead now, so remove the leftovers.  What's left
at this point is:

 - various checks inside the block layer.
 - sanity checks in bio based drivers.
 - now unused bio_empty_barrier helper.
 - Xen blockfront use of BLKIF_OP_WRITE_BARRIER - it's dead for a while,
   but Xen really needs to sort out it's barrier situaton.
 - setting of ordered tags in uas - dead code copied from old scsi
   drivers.
 - scsi different retry for barriers - it's dead and should have been
   removed when flushes were converted to FS requests.
 - blktrace handling of barriers - removed.  Someone who knows blktrace
   better should add support for REQ_FLUSH and REQ_FUA, though.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-11-10 14:54:09 +01:00
Darren Hart
4c115e951d futex: Address compiler warnings in exit_robust_list
Since commit 1dcc41bb (futex: Change 3rd arg of fetch_robust_entry()
to unsigned int*) some gcc versions decided to emit the following
warning:

kernel/futex.c: In function ‘exit_robust_list’:
kernel/futex.c:2492: warning: ‘next_pi’ may be used uninitialized in this function

The commit did not introduce the warning as gcc should have warned
before that commit as well. It's just gcc being silly.

The code path really can't result in next_pi being unitialized (or
should not), but let's keep the build clean. Annotate next_pi as an
uninitialized_var.

[ tglx: Addressed the same issue in futex_compat.c and massaged the
  	changelog ]

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Tested-by: Matt Fleming <matt@console-pimps.org>
Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <1288897200-13008-1-git-send-email-dvhart@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-11-10 13:27:50 +01:00
Sergey Senozhatsky
c0deae8c95 posix-cpu-timers: Rcu_read_lock/unlock protect find_task_by_vpid call
Commit 4221a9918e "Add RCU check for
find_task_by_vpid()" introduced rcu_lockdep_assert to find_task_by_pid_ns.
Add rcu_read_lock/rcu_read_unlock to call find_task_by_vpid.

Tetsuo Handa wrote:
| Quoting from one of posts in that thead
| http://kerneltrap.org/mailarchive/linux-kernel/2010/2/8/4536388
|
|| Usually tasklist gives enough protection, but if copy_process() fails
|| it calls free_pid() lockless and does call_rcu(delayed_put_pid().
|| This means, without rcu lock find_pid_ns() can't scan the hash table
|| safely.

Thomas Gleixner wrote:
| We can remove the tasklist_lock while at it. rcu_read_lock is enough.

Patch also replaces thread_group_leader with has_group_leader_pid
in accordance to comment by Oleg Nesterov:

| ... thread_group_leader() check is not relaible without 
| tasklist. If we race with de_thread() find_task_by_vpid() can find
| the new leader before it updates its ->group_leader.
|
| perhaps it makes sense to change posix_cpu_timer_create() to use 
| has_group_leader_pid() instead, just to make this code not look racy
| and avoid adding new problems.


Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
LKML-Reference: <20101103165256.GD30053@swordfish.minsk.epam.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-11-10 13:07:06 +01:00
Heiko Carstens
becf91f187 [S390] ftrace: build without frame pointers on s390
s390 doesn't need FRAME_POINTERS in order to have a working function tracer.
We don't need frame pointers in order to get strack traces since we always
have valid backchains by using the -mkernel-backchain gcc option.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-11-10 10:05:54 +01:00
David Daney
433039e97f watchdog: Fix section mismatch and potential undefined behavior.
Commit d9ca07a05c ("watchdog: Avoid kernel crash when disabling
watchdog") introduces a section mismatch.

Now that we reference no_watchdog from non-__init code it can no longer
be __initdata.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-05 17:45:35 -07:00
Oleg Nesterov
e0a7021710 posix-cpu-timers: workaround to suppress the problems with mt exec
posix-cpu-timers.c correctly assumes that the dying process does
posix_cpu_timers_exit_group() and removes all !CPUCLOCK_PERTHREAD
timers from signal->cpu_timers list.

But, it also assumes that timer->it.cpu.task is always the group
leader, and thus the dead ->task means the dead thread group.

This is obviously not true after de_thread() changes the leader.
After that almost every posix_cpu_timer_ method has problems.

It is not simple to fix this bug correctly. First of all, I think
that timer->it.cpu should use struct pid instead of task_struct.
Also, the locking should be reworked completely. In particular,
tasklist_lock should not be used at all. This all needs a lot of
nontrivial and hard-to-test changes.

Change __exit_signal() to do posix_cpu_timers_exit_group() when
the old leader dies during exec. This is not the fix, just the
temporary hack to hide the problem for 2.6.37 and stable. IOW,
this is obviously wrong but this is what we currently have anyway:
cpu timers do not work after mt exec.

In theory this change adds another race. The exiting leader can
detach the timers which were attached to the new leader. However,
the window between de_thread() and release_task() is small, we
can pretend that sys_timer_create() was called before de_thread().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-05 14:16:03 -07:00
Jesper Juhl
408af87a39 Clean up relay_alloc_page_array() slightly by using vzalloc rather than vmalloc and memset
We can optimize kernel/relay.c::relay_alloc_page_array() slightly by
using vzalloc.  The patch makes these changes:

 - use vzalloc instead of vmalloc+memset.
 - remove redundant local variable 'array'.
 - declare local 'pa_size' as const.

Cuts down nicely on both source and object-code size.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-05 08:21:34 -07:00
Linus Torvalds
82279e6bd7 Merge branches 'irq-core-for-linus' and 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  genirq: Fix up irq_node() for irq_data changes.
  genirq: Add single IRQ reservation helper
  genirq: Warn if enable_irq is called before irq is set up

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  semaphore: Remove mutex emulation
  staging: Final semaphore cleanup
  jbd2: Convert jbd2_slab_create_sem to mutex
  hpfs: Convert sbi->hpfs_creation_de to mutex

Fix up trivial change/delete conflicts with deleted 'dream' drivers
(drivers/staging/dream/camera/{mt9d112.c,mt9p012_fox.c,mt9t013.c,s5k3e2fx.c})
2010-10-31 20:40:24 -04:00
Linus Torvalds
f02a38d86a Merge branches 'perf-fixes-for-linus' and 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  jump label: Add work around to i386 gcc asm goto bug
  x86, ftrace: Use safe noops, drop trap test
  jump_label: Fix unaligned traps on sparc.
  jump label: Make arch_jump_label_text_poke_early() optional
  jump label: Fix error with preempt disable holding mutex
  oprofile: Remove deprecated use of flush_scheduled_work()
  oprofile: Fix the hang while taking the cpu offline
  jump label: Fix deadlock b/w jump_label_mutex vs. text_mutex
  jump label: Fix module __init section race

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Check irq_remapped instead of remapping_enabled in destroy_irq()
2010-10-30 11:43:26 -07:00
Al Viro
120a795da0 audit mmap
Normal syscall audit doesn't catch 5th argument of syscall.  It also
doesn't catch the contents of userland structures pointed to be
syscall argument, so for both old and new mmap(2) ABI it doesn't
record the descriptor we are mapping.  For old one it also misses
flags.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30 08:45:43 -04:00
Thomas Gleixner
ab263f47c9 audit: Use rcu for task lookup protection
Protect the task lookups in audit_receive_msg() with rcu_read_lock()
instead of tasklist_lock and use lock/unlock_sighand to protect
against the exit race.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30 08:45:42 -04:00
Thomas Gleixner
207032051a audit: Do not send uninitialized data for AUDIT_TTY_GET
audit_receive_msg() sends uninitialized data for AUDIT_TTY_GET when
the task was not found.

Send reply only when task was found.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30 08:45:42 -04:00
Thomas Gleixner
3c80fe4ac9 audit: Call tty_audit_push_task() outside preempt disabled
While auditing all tasklist_lock read_lock sites I stumbled over the
following call chain:

audit_prepare_user_tty()
  read_lock(&tasklist_lock);
  tty_audit_push_task();
     mutex_lock(&buf->mutex);

     --> buf->mutex is locked with preemption disabled.

Solve this by acquiring a reference to the task struct under
rcu_read_lock and call tty_audit_push_task outside of the preempt
disabled region.

Move all code which needs to be protected by sighand lock into
tty_audit_push_task() and use lock/unlock_sighand as we do not hold
tasklist_lock.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30 08:45:25 -04:00
Al Viro
f7a998a949 in untag_chunk() we need to do alloc_chunk() a bit earlier
... while we are not holding spinlocks.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30 02:18:32 -04:00
Stephen Hemminger
b8800aa5d9 audit: make functions static
I was doing some namespace checks and found some simple stuff in
audit that could be cleaned up. Make some functions static, and
put const on make_reply payload arg.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30 01:42:19 -04:00
Miloslav Trmac
d29be158a6 Audit: add support to match lsm labels on user audit messages
Add support for matching by security label (e.g. SELinux context) of
the sender of an user-space audit record.

The audit filter code already allows user space to configure such
filters, but they were ignored during evaluation.  This patch implements
evaluation of these filters.

For example, after application of this patch, PAM authentication logs
caused by cron can be disabled using
	auditctl -a user,never -F subj_type=crond_t

Signed-off-by: Miloslav Trmac <mitr@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30 01:41:57 -04:00
Linus Torvalds
1e431a9d64 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
  kgdb,ppc: Individual register get/set for ppc
  kgdbts: prevent re-entry to kgdbts before it unregisters
  debug_core,x86,blackfin: Clean up hw debug disable API
  kdb: Fix early debugging crash regression
  kgdb,arm: fix register dump
  kdb: fix per_cpu command to remove supress mask
  kdb: Add kdb kernel module sample
2010-10-29 11:49:38 -07:00
Dongdong Deng
d7ba979d45 debug_core,x86,blackfin: Clean up hw debug disable API
The kgdb_disable_hw_debug() was an architecture specific function for
disabling all hardware breakpoints on a per cpu basis when entering
the debug core.

This patch will remove the weak function kdbg_disable_hw_debug() and
change it into a call back which lives with the rest of hw breakpoint
call backs in struct kgdb_arch.

Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-29 13:14:41 -05:00
Jason Wessel
578bd4dfcd kdb: Fix early debugging crash regression
The kdb_current legally be equal to NULL in the early boot of the x86
arch.  The problem pcan be observed by booting with the kernel arguments:

    earlyprintk=vga ekgdboc=kbd kgdbwait

The kdb shell will oops on entry and recursively fault because it
cannot get past the final stage of shell initialization.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-29 13:14:41 -05:00
Jason Wessel
931ea24819 kdb: fix per_cpu command to remove supress mask
Rusty pointed out that the per_cpu command uses up lots of space on
the stack and the cpu supress mask is probably not needed.

This patch removes the need for the supress mask as well as fixing up
the following problems with the kdb per_cpu command:
  * The per_cpu command should allow an address as an argument
  * When you have more data than can be displayed on one screen allow
    the user to break out of the print loop.

Reported-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-29 13:14:40 -05:00
Steven Rostedt
95bcd683fb jump label: Make arch_jump_label_text_poke_early() optional
Some archs do not need to do anything special for jump labels on
startup (like MIPS).  This patch adds a weak function stub for
arch_jump_label_text_poke_early();

Cc: Jason Baron <jbaron@redhat.com>
Cc: David Miller <davem@davemloft.net>
Cc: David Daney <ddaney@caviumnetworks.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <1286218615-24011-2-git-send-email-ddaney@caviumnetworks.com>
LKML-Reference: <20101015201037.703989993@goodmis.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-29 12:56:13 -04:00
Steven Rostedt
de31c3ca81 jump label: Fix error with preempt disable holding mutex
Kprobes and jump label were having a race between mutexes that
was fixed by reordering the jump label. But this reordering
moved the jump label mutex into a preempt disable location.

This patch does a little fiddling to move the grabbing of
the jump label mutex from inside the preempt disable section
and still keep the order correct between the mutex and the
kprobes lock.

Reported-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Jason Baron <jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-29 12:55:55 -04:00
Linus Torvalds
53113b06e4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (29 commits)
  braino in internal.h
  convert simple cases of nfs-related ->get_sb() to ->mount()
  convert btrfs
  convert ceph
  convert gfs2
  convert afs
  convert ecryptfs
  convert sysfs
  convert cgroup and cpuset
  switch get_sb_ns() users
  switch procfs to ->mount()
  setting ->proc_mnt doesn't belong in proc_get_sb()
  convert cifs
  convert nilfs
  switch logfs to ->mount()
  logfs: fix a leak in get_sb
  logfs get_sb, part 3
  logfs get_sb, part 2
  logfs get_sb massage, part 1
  convert v9fs
  ...
2010-10-29 08:06:25 -07:00
Linus Torvalds
37542b6a7e Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched_stat: Update sched_info_queue/dequeue() code comments
  sched, cgroup: Fixup broken cgroup movement
2010-10-29 08:05:33 -07:00
Al Viro
f7e835710a convert cgroup and cpuset
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-29 04:17:06 -04:00
Linus Torvalds
e9f29c9a56 Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (27 commits)
  x86: allocate space within a region top-down
  x86: update iomem_resource end based on CPU physical address capabilities
  x86/PCI: allocate space from the end of a region, not the beginning
  PCI: allocate bus resources from the top down
  resources: support allocating space within a region from the top down
  resources: handle overflow when aligning start of available area
  resources: ensure callback doesn't allocate outside available space
  resources: factor out resource_clip() to simplify find_resource()
  resources: add a default alignf to simplify find_resource()
  x86/PCI: MMCONFIG: fix region end calculation
  PCI: Add support for polling PME state on suspended legacy PCI devices
  PCI: Export some PCI PM functionality
  PCI: fix message typo
  PCI: log vendor/device ID always
  PCI: update Intel chipset names and defines
  PCI: use new ccflags variable in Makefile
  PCI: add PCI_MSIX_TABLE/PBA defines
  PCI: add PCI vendor id for STmicroelectronics
  x86/PCI: irq and pci_ids patch for Intel Patsburg DeviceIDs
  PCI: OLPC: Only enable PCI configuration type override on XO-1
  ...
2010-10-28 11:59:52 -07:00
Jason Baron
91bad2f8d3 jump label: Fix deadlock b/w jump_label_mutex vs. text_mutex
register_kprobe() downs the 'text_mutex' and then calls
jump_label_text_reserved(), which downs the 'jump_label_mutex'.
However, the jump label code takes those mutexes in the reverse
order.

Fix by requiring the caller of jump_label_text_reserved() to do
the jump label locking via the newly added: jump_label_lock(),
jump_label_unlock(). Currently, kprobes is the only user
of jump_label_text_reserved().

Reported-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <759032c48d5e30c27f0bba003d09bffa8e9f28bb.1285965957.git.jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-28 09:17:40 -04:00
Jason Baron
b842f8faf6 jump label: Fix module __init section race
Jump label uses is_module_text_address() to ensure that the module
__init sections are valid before updating them. However, between the
check for a valid module __init section and the subsequent jump
label update, the module's __init section could be freed out from under
us.

We fix this potential race by adding a notifier callback to the
MODULE_STATE_LIVE state. This notifier is called *after* the __init
section has been run but before it is going to be freed. In the
callback, the jump label code zeros the key value for any __init jump
code within the module, and we add a check for a non-zero key value when
we update jump labels. In this way we require no additional data
structures.

Thanks to Mathieu Desnoyers for pointing out this race condition.

Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <c6f037b7598777668025ceedd9294212fd95fa34.1285965957.git.jbaron@redhat.com>

[ Renamed remove_module_init() to remove_jump_label_module_init()
  as suggested by Masami Hiramatsu. ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-28 09:17:02 -04:00
Linus Torvalds
bdab225015 Merge git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-mn10300
* git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-mn10300: (44 commits)
  MN10300: Save frame pointer in thread_info struct rather than global var
  MN10300: Change "Matsushita" to "Panasonic".
  MN10300: Create a defconfig for the ASB2364 board
  MN10300: Update the ASB2303 defconfig
  MN10300: ASB2364: Add support for SMSC911X and SMC911X
  MN10300: ASB2364: Handle the IRQ multiplexer in the FPGA
  MN10300: Generic time support
  MN10300: Specify an ELF HWCAP flag for MN10300 Atomic Operations Unit support
  MN10300: Map userspace atomic op regs as a vmalloc page
  MN10300: And Panasonic AM34 subarch and implement SMP
  MN10300: Delete idle_timestamp from irq_cpustat_t
  MN10300: Make various interrupt priority settings configurable
  MN10300: Optimise do_csum()
  MN10300: Implement atomic ops using atomic ops unit
  MN10300: Make the FPU operate in non-lazy mode under SMP
  MN10300: SMP TLB flushing
  MN10300: Use the [ID]PTEL2 registers rather than [ID]PTEL for TLB control
  MN10300: Make the use of PIDR to mark TLB entries controllable
  MN10300: Rename __flush_tlb*() to local_flush_tlb*()
  MN10300: AM34 erratum requires MMUCTR read and write on exception entry
  ...
2010-10-27 18:53:26 -07:00
Linus Torvalds
a042e26137 Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (50 commits)
  perf python scripting: Add futex-contention script
  perf python scripting: Fixup cut'n'paste error in sctop script
  perf scripting: Shut up 'perf record' final status
  perf record: Remove newline character from perror() argument
  perf python scripting: Support fedora 11 (audit 1.7.17)
  perf python scripting: Improve the syscalls-by-pid script
  perf python scripting: print the syscall name on sctop
  perf python scripting: Improve the syscalls-counts script
  perf python scripting: Improve the failed-syscalls-by-pid script
  kprobes: Remove redundant text_mutex lock in optimize
  x86/oprofile: Fix uninitialized variable use in debug printk
  tracing: Fix 'faild' -> 'failed' typo
  perf probe: Fix format specified for Dwarf_Off parameter
  perf trace: Fix detection of script extension
  perf trace: Use $PERF_EXEC_PATH in canned report scripts
  perf tools: Document event modifiers
  perf tools: Remove direct slang.h include
  perf_events: Fix for transaction recovery in group_sched_in()
  perf_events: Revert: Fix transaction recovery in group_sched_in()
  perf, x86: Use NUMA aware allocations for PEBS/BTS/DS allocations
  ...
2010-10-27 18:48:00 -07:00
Linus Torvalds
f66dd539fe Merge branch 'module' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* 'module' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  NULL-terminate all pci_device_id tables
  (trivial) Fix compiler warning in kernel/modules.c
2010-10-27 18:47:39 -07:00
Zimny Lech
61d8e11e51 Remove duplicate includes from many files
Signed-off-by: Zimny Lech <napohybelskurwysynom2010@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:18 -07:00
Huang Shijie
5de1cb2d0f kernel/resource.c: handle reinsertion of an already-inserted resource
If the same resource is inserted to the resource tree (maybe not on
purpose), a dead loop will be created.  In this situation, The kernel does
not report any warning or error :(

  The command below will show a endless print.
  #cat /proc/iomem

[akpm@linux-foundation.org: add WARN_ON()]
Signed-off-by: Huang Shijie <shijie8@gmail.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:18 -07:00
Michael Holzheu
d57af9b214 taskstats: use real microsecond granularity for CPU times
The taskstats interface uses microsecond granularity for the user and
system time values.  The conversion from cputime to the taskstats values
uses the cputime_to_msecs primitive which effectively limits the
granularity to milliseconds.  Add the cputime_to_usecs primitive for
architectures that have better, more precise CPU time values.  Remove
cputime_to_msecs primitive because there are no more users left.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Luck Tony <tony.luck@intel.com>
Cc: Shailabh Nagar <nagar1234@in.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Shailabh Nagar <nagar@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:17 -07:00
Michael Holzheu
3d9e0cf1fe taskstats: split fill_pid function
Separate the finding of a task_struct by pid or tgid from filling the
taskstats data. This makes the code more readable.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:17 -07:00
Michael Holzheu
9323312592 taskstats: separate taskstats commands
Move each taskstats command into a single function.  This makes the code
more readable and makes it easier to add new commands.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:17 -07:00
Jeff Mahoney
8589312069 delayacct: align to 8 byte boundary on 64-bit systems
prepare_reply() sets up an skb for the response.  The payload contains:

 +--------------------------------+
 | genlmsghdr - 4 bytes           |
 +--------------------------------+
 | NLA header - 4 bytes           | /* Aggregate header */
 +-+------------------------------+
 | | NLA header - 4 bytes         | /* PID header */
 | +------------------------------+
 | | pid/tgid   - 4 bytes         |
 | +------------------------------+
 | | NLA header - 4 bytes         | /* stats header */
 | + -----------------------------+ <- oops. aligned on 4 byte boundary
 | | struct taskstats - 328 bytes |
 +-+------------------------------+

The start of the taskstats struct must be 8 byte aligned on IA64 (and
other systems with 8 byte alignment rules for 64-bit types) or runtime
alignment warnings will be issued.

This patch pads the pid/tgid field out to sizeof(long), which forces the
alignment of taskstats.  The getdelays userspace code is ok with this
since it assumes 32-bit pid/tgid and then honors that header's length
field.

An array is used to avoid exposing kernel memory contents to userspace in
the response.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:17 -07:00
KAMEZAWA Hiroyuki
478735e388 /proc/stat: fix scalability of irq sum of all cpu
In /proc/stat, the number of per-IRQ event is shown by making a sum each
irq's events on all cpus.  But we can make use of kstat_irqs().

kstat_irqs() do the same calculation, If !CONFIG_GENERIC_HARDIRQ,
it's not a big cost. (Both of the number of cpus and irqs are small.)

If a system is very big and CONFIG_GENERIC_HARDIRQ, it does

	for_each_irq()
		for_each_cpu()
			- look up a radix tree
			- read desc->irq_stat[cpu]
This seems not efficient. This patch adds kstat_irqs() for
CONFIG_GENRIC_HARDIRQ and change the calculation as

	for_each_irq()
		look up radix tree
		for_each_cpu()
			- read desc->irq_stat[cpu]

This reduces cost.

A test on (4096cpusp, 256 nodes, 4592 irqs) host (by Jack Steiner)

%time cat /proc/stat > /dev/null

Before Patch:	 2.459 sec
After Patch :	  .561 sec

[akpm@linux-foundation.org: unexport kstat_irqs, coding-style tweaks]
[akpm@linux-foundation.org: fix unused variable 'per_irq_sum']
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: Jack Steiner <steiner@sgi.com>
Acked-by: Jack Steiner <steiner@sgi.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:13 -07:00
Namhyung Kim
d16e15f5b0 exit: add lock context annotation on find_new_reaper()
find_new_reaper() releases and regrabs tasklist_lock but was missing
proper annotations.  Add it.  This remove following sparse warning:

 warning: context imbalance in 'find_new_reaper' - unexpected unlock

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:13 -07:00
KOSAKI Motohiro
9b1bf12d5d signals: move cred_guard_mutex from task_struct to signal_struct
Oleg Nesterov pointed out we have to prevent multiple-threads-inside-exec
itself and we can reuse ->cred_guard_mutex for it.  Yes, concurrent
execve() has no worth.

Let's move ->cred_guard_mutex from task_struct to signal_struct.  It
naturally prevent multiple-threads-inside-exec.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:12 -07:00
Namhyung Kim
b840115083 signals: annotate lock context change on ptrace_stop()
ptrace_stop() releases and regrabs current->sighand->siglock but was
missing proper annotation.  Add it.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:12 -07:00
Namhyung Kim
b8ed374e20 signals: annotate lock_task_sighand()
lock_task_sighand() grabs sighand->siglock in case of returning non-NULL
but unlock_task_sighand() releases it unconditionally.  This leads sparse
to complain about the lock context imbalance.  Rename and wrap
lock_task_sighand() using __cond_lock() macro to make sparse happy.

Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:12 -07:00
Namhyung Kim
9fed81dc40 ptrace: cleanup ptrace_request()
Use new 'datavp' and 'datalp' variables to remove unnecesary castings.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:10 -07:00
Namhyung Kim
4abf986960 ptrace: change signature of sys_ptrace() and friends
Since userspace API of ptrace syscall defines @addr and @data as void
pointers, it would be more appropriate to define them as unsigned long in
kernel.  Therefore related functions are changed also.

'unsigned long' is typically used in other places in kernel as an opaque
data type and that using this helps cleaning up a lot of warnings from
sparse.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:10 -07:00
Namhyung Kim
c4b5ed250e ptrace: annotate lock context change on exit_ptrace()
exit_ptrace() releases and regrabs tasklist_lock but was missing proper
annotation.  Add it.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:10 -07:00
Daniel Lezcano
45531757b4 cgroup: notify ns_cgroup deprecated
The ns_cgroup will be removed very soon.  Let's warn, for this version,
ns_cgroup is deprecated.

Make ns_cgroup and clone_children exclusive.  If the clone_children is set
and the ns_cgroup is mounted, let's fail with EINVAL when the ns_cgroup
subsys is created (a printk will help the user to understand why the
creation fails).

Update the feature remove schedule file with the deprecated ns_cgroup.

Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:09 -07:00
Evgeny Kuznetsov
f4a2589fea cgroups: add check for strcpy destination string overflow
Function "strcpy" is used without check for maximum allowed source string
length and could cause destination string overflow.  Check for string
length is added before using "strcpy".  Function now is return error if
source string length is more than a maximum.

akpm: presently considered NotABug, but add the check for general
future-safeness and robustness.

Signed-off-by: Evgeny Kuznetsov <EXT-Eugeny.Kuznetsov@nokia.com>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:09 -07:00
Daniel Lezcano
32a8cf235e cgroup: make the mount options parsing more accurate
Current behavior:
=================

(1) When we mount a cgroup, we can specify the 'all' option which
    means to enable all the cgroup subsystems.  This is the default option
    when no option is specified.

(2) If we want to mount a cgroup with a subset of the supported cgroup
    subsystems, we have to specify a subsystems name list for the mount
    option.

(3) If we specify another option like 'noprefix' or 'release_agent',
    the actual code wants the 'all' or a subsystem name option specified
    also.  Not critical but a bit not friendly as we should assume (1) in
    this case.

(4) Logically, the 'all' option is mutually exclusive with a subsystem
    name, but this is not detected.

In other words:
 succeed : mount -t cgroup -o all,freezer cgroup /cgroup
	=> is it 'all' or 'freezer' ?
 fails : mount -t cgroup -o noprefix cgroup /cgroup
	=> succeed if we do '-o noprefix,all'

The following patches consolidate a bit the mount options check.

New behavior:
=============

(1) untouched
(2) untouched
(3) the 'all' option will be by default when specifying other than
    a subsystem name option
(4) raises an error

In other words:
 fails   : mount -t cgroup -o all,freezer cgroup /cgroup
 succeed : mount -t cgroup -o noprefix cgroup /cgroup

For the sake of lisibility, the if ... then ... else ... if ...
indentation when parsing the options has been changed to:
if ... then
	...
	continue
fi

Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: Paul Menage <menage@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jamal Hadi Salim <hadi@cyberus.ca>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:09 -07:00
Daniel Lezcano
97978e6d1f cgroup: add clone_children control file
The ns_cgroup is a control group interacting with the namespaces.  When a
new namespace is created, a corresponding cgroup is automatically created
too.  The cgroup name is the pid of the process who did 'unshare' or the
child of 'clone'.

This cgroup is tied with the namespace because it prevents a process to
escape the control group and use the post_clone callback, so the child
cgroup inherits the values of the parent cgroup.

Unfortunately, the more we use this cgroup and the more we are facing
problems with it:

(1) when a process unshares, the cgroup name may conflict with a
    previous cgroup with the same pid, so unshare or clone return -EEXIST

(2) the cgroup creation is out of control because there may have an
    application creating several namespaces where the system will
    automatically create several cgroups in his back and let them on the
    cgroupfs (eg.  a vrf based on the network namespace).

(3) the mix of (1) and (2) force an administrator to regularly check
    and clean these cgroups.

This patchset removes the ns_cgroup by adding a new flag to the cgroup and
the cgroupfs mount option.  It enables the copy of the parent cgroup when
a child cgroup is created.  We can then safely remove the ns_cgroup as
this flag brings a compatibility.  We have now to manually create and add
the task to a cgroup, which is consistent with the cgroup framework.

This patch:

Sent as an answer to a previous thread around the ns_cgroup.

https://lists.linux-foundation.org/pipermail/containers/2009-June/018627.html

It adds a control file 'clone_children' for a cgroup.  This control file
is a boolean specifying if the child cgroup should be a clone of the
parent cgroup or not.  The default value is 'false'.

This flag makes the child cgroup to call the post_clone callback of all
the subsystem, if it is available.

At present, the cpuset is the only one which had implemented the
post_clone callback.

The option can be set at mount time by specifying the 'clone_children'
mount option.

Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Paul Menage <menage@google.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Jamal Hadi Salim <hadi@cyberus.ca>
Cc: Matt Helsley <matthltc@us.ibm.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:09 -07:00
Tomasz Buchert
2d3cbf8bc8 cgroup_freezer: update_freezer_state() does incorrect state transitions
There are 4 state transitions possible for a freezer.  Only FREEZING ->
FROZEN transaction is done lazily.  This patch allows update_freezer_state
only to perform this transaction and renames the function to
update_if_frozen.

Moreover is_task_frozen_enough function is removed and its every occurence
is replaced with frozen().  Therefore for a group to become FROZEN every
task must be frozen.

The previous version could trigger a following bug: When cgroup is in the
process of freezing (but none of its tasks are frozen yet),
update_freezer_state() (called from freezer_read or freezer_write) would
incorrectly report that a group is 'THAWED' (because nfrozen = 0),
allowing the transaction FREEZING -> THAWED without writing anything to
'freezer.state'.  This is incorrect according to the documentation.  This
could result in a 'THAWED' cgroup with frozen tasks inside.

A code to reproduce this bug is available here:
http://pentium.hopto.org/~thinred/repos/linux-misc/freezer_bug2.c

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Tomasz Buchert <tomasz.buchert@inria.fr>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:08 -07:00
Tomasz Buchert
0bdba580ab cgroup_freezer: fix can_attach() to prohibit moving from/to freezing/frozen cgroups
It is possible to move a task from its cgroup even if this group is
'FREEZING'.  This results in a nasty bug - the moved task will become
frozen OUTSIDE its original cgroup and will remain in a permanent 'D'
state.

This patch allows to migrate the task only between THAWED cgroups.

This behavior was observed and easily reproduced on a single core laptop.
Notice that reproducibility depends highly on the machine used.  Program
and instructions how to reproduce the bug can be fetched from:
http://pentium.hopto.org/~thinred/repos/linux-misc/freezer_bug.c

Signed-off-by: Tomasz Buchert <tomasz.buchert@inria.fr>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:08 -07:00
Tomasz Buchert
d5de4ddb1b cgroup_freezer: unnecessary test in cgroup_freezing_or_frozen()
The root freezer_state is always CGROUP_THAWED so we can remove the
special case from the code.  The test itself can be handy and is extracted
to static function.

Signed-off-by: Tomasz Buchert <tomasz.buchert@inria.fr>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:08 -07:00
David Howells
3a5f65df5a Typedef SMP call function pointer
Typedef the pointer to the function to be called by smp_call_function() and
friends:

	typedef void (*smp_call_func_t)(void *info);

as it is used in a fair number of places.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-arch@vger.kernel.org
2010-10-27 17:28:36 +01:00
Michał Mirosław
abbce906d0 (trivial) Fix compiler warning in kernel/modules.c
Building with CONFIG_KALLSYMS=n gives following warning:

/mnt/src/linux-git/kernel/module.c: In function ‘post_relocation’:
/mnt/src/linux-git/kernel/module.c:2534:2: warning: passing argument 2 of ‘add_kallsyms’ discards qualifiers from pointer target type
/mnt/src/linux-git/kernel/module.c:2038:13: note: expected ‘struct load_info *’ but argument is of type ‘const struct load_info *’

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-10-27 20:33:05 +10:30
Linus Torvalds
426e1f5cec Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (52 commits)
  split invalidate_inodes()
  fs: skip I_FREEING inodes in writeback_sb_inodes
  fs: fold invalidate_list into invalidate_inodes
  fs: do not drop inode_lock in dispose_list
  fs: inode split IO and LRU lists
  fs: switch bdev inode bdi's correctly
  fs: fix buffer invalidation in invalidate_list
  fsnotify: use dget_parent
  smbfs: use dget_parent
  exportfs: use dget_parent
  fs: use RCU read side protection in d_validate
  fs: clean up dentry lru modification
  fs: split __shrink_dcache_sb
  fs: improve DCACHE_REFERENCED usage
  fs: use percpu counter for nr_dentry and nr_dentry_unused
  fs: simplify __d_free
  fs: take dcache_lock inside __d_path
  fs: do not assign default i_ino in new_inode
  fs: introduce a per-cpu last_ino allocator
  new helper: ihold()
  ...
2010-10-26 17:58:44 -07:00
Randy Dunlap
ee2f154a59 docbook: add more wait/wake/completion to device-drivers docbook
Add more wait, wake, and completion interfaces to the device-drivers
docbook.

Fix kernel-doc notation in the added files.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 17:32:41 -07:00
Namhyung Kim
f5d87d851d printk: declare printk_ratelimit_state in ratelimit.h
Adding declaration of printk_ratelimit_state in ratelimit.h removes
potential build breakage and following sparse warning:

 kernel/printk.c:1426:1: warning: symbol 'printk_ratelimit_state' was not declared. Should it be static?

[akpm@linux-foundation.org: remove unneeded ifdef]
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:16 -07:00
Namhyung Kim
674dff6507 printk: change type of 'boot_delay' to int *
get_option() takes its 2nd arg as int * so passing boot_delay to it
caused following warnings from sparse:

 kernel/printk.c:223:27: warning: incorrect type in argument 2 (different signedness)
 kernel/printk.c:223:27:    expected int *pint
 kernel/printk.c:223:27:    got unsigned int static [toplevel] *<noident>

Since boot_delay can't grow more than 10,000 changing it to 'int *'
will not produce any problem.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:16 -07:00
Namhyung Kim
8155c02a44 printk: add lock context annotation
acquire_console_semaphore_for_printk() releases logbuf_lock but
was missing proper annotation. Add it.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:16 -07:00
Namhyung Kim
6c095efd82 printk: fixup declaration of kmsg_reasons
Move redundant 'const' after '*' to make pointer itself const

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:16 -07:00
Akinobu Mita
4ce6494dbd stop_machine: convert cpu notifier to return encapsulate errno value
In commit e6bde73b07 ("cpu-hotplug: return
better errno on cpu hotplug failure"), the cpu notifier can return an
encapsulated errno value.

This converts the cpu notifier to return an encapsulated errno value for
stop_machine().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:15 -07:00
Rakib Mullick
ca51c5a763 kernel/stop_machine.c: fix unused variable warning
kernel/stop_machine.c: In function `cpu_stopper_thread':
kernel/stop_machine.c:265: warning: unused variable `ksym_buf'

ksym_buf[] is unused if WARN_ON() is a no-op.

Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:15 -07:00
Eric Dumazet
518de9b39e fs: allow for more than 2^31 files
Robin Holt tried to boot a 16TB system and found af_unix was overflowing
a 32bit value :

<quote>

We were seeing a failure which prevented boot.  The kernel was incapable
of creating either a named pipe or unix domain socket.  This comes down
to a common kernel function called unix_create1() which does:

        atomic_inc(&unix_nr_socks);
        if (atomic_read(&unix_nr_socks) > 2 * get_max_files())
                goto out;

The function get_max_files() is a simple return of files_stat.max_files.
files_stat.max_files is a signed integer and is computed in
fs/file_table.c's files_init().

        n = (mempages * (PAGE_SIZE / 1024)) / 10;
        files_stat.max_files = n;

In our case, mempages (total_ram_pages) is approx 3,758,096,384
(0xe0000000).  That leaves max_files at approximately 1,503,238,553.
This causes 2 * get_max_files() to integer overflow.

</quote>

Fix is to let /proc/sys/fs/file-nr & /proc/sys/fs/file-max use long
integers, and change af_unix to use an atomic_long_t instead of atomic_t.

get_max_files() is changed to return an unsigned long.  get_nr_files() is
changed to return a long.

unix_nr_socks is changed from atomic_t to atomic_long_t, while not
strictly needed to address Robin problem.

Before patch (on a 64bit kernel) :
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
-18446744071562067968

After patch:
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
2147483648
# cat /proc/sys/fs/file-nr
704     0       2147483648

Reported-by: Robin Holt <holt@sgi.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David Miller <davem@davemloft.net>
Reviewed-by: Robin Holt <holt@sgi.com>
Tested-by: Robin Holt <holt@sgi.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:15 -07:00
Namhyung Kim
571428be55 kernel/user.c: add lock release annotation on free_user()
free_user() releases uidhash_lock but was missing annotation.  Add it.
This removes following sparse warnings:

 include/linux/spinlock.h:339:9: warning: context imbalance in 'free_user' - unexpected unlock
 kernel/user.c:120:6: warning: context imbalance in 'free_uid' - wrong count at exit

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Dhaval Giani <dhaval.giani@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:15 -07:00
Andrew Morton
ca1cab37d9 workqueues: s/ON_STACK/ONSTACK/
Silly though it is, completions and wait_queue_heads use foo_ONSTACK
(COMPLETION_INITIALIZER_ONSTACK, DECLARE_COMPLETION_ONSTACK,
__WAIT_QUEUE_HEAD_INIT_ONSTACK and DECLARE_WAIT_QUEUE_HEAD_ONSTACK) so I
guess workqueues should do the same thing.

s/INIT_WORK_ON_STACK/INIT_WORK_ONSTACK/
s/INIT_DELAYED_WORK_ON_STACK/INIT_DELAYED_WORK_ONSTACK/

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:14 -07:00
Jan Beulich
3ecb01df32 use clear_page()/copy_page() in favor of memset()/memcpy() on whole pages
After all that's what they are intended for.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:13 -07:00
Peter Zijlstra
61ecdb801e mm: strictly nested kmap_atomic()
Ensure kmap_atomic() usage is strictly nested

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:08 -07:00
Ying Han
3d5992d2ac oom: add per-mm oom disable count
It's pointless to kill a task if another thread sharing its mm cannot be
killed to allow future memory freeing.  A subsequent patch will prevent
kills in such cases, but first it's necessary to have a way to flag a task
that shares memory with an OOM_DISABLE task that doesn't incur an
additional tasklist scan, which would make select_bad_process() an O(n^2)
function.

This patch adds an atomic counter to struct mm_struct that follows how
many threads attached to it have an oom_score_adj of OOM_SCORE_ADJ_MIN.
They cannot be killed by the kernel, so their memory cannot be freed in
oom conditions.

This only requires task_lock() on the task that we're operating on, it
does not require mm->mmap_sem since task_lock() pins the mm and the
operation is atomic.

[rientjes@google.com: changelog and sys_unshare() code]
[rientjes@google.com: protect oom_disable_count with task_lock in fork]
[rientjes@google.com: use old_mm for oom_disable_count in exec]
Signed-off-by: Ying Han <yinghan@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:05 -07:00
Bjorn Helgaas
e7f8567db9 resources: support allocating space within a region from the top down
Allocate space from the top of a region first, then work downward,
if an architecture desires this.

When we allocate space from a resource, we look for gaps between children
of the resource.  Previously, we always looked at gaps from the bottom up.
For example, given this:

    [mem 0xbff00000-0xf7ffffff] PCI Bus 0000:00
      [mem 0xbff00000-0xbfffffff] gap -- available
      [mem 0xc0000000-0xdfffffff] PCI Bus 0000:02
      [mem 0xe0000000-0xf7ffffff] gap -- available

we attempted to allocate from the [mem 0xbff00000-0xbfffffff] gap first,
then the [mem 0xe0000000-0xf7ffffff] gap.

With this patch an architecture can choose to allocate from the top gap
[mem 0xe0000000-0xf7ffffff] first.

We can't do this across the board because iomem_resource.end is initialized
to 0xffffffff_ffffffff on 64-bit architectures, and most machines can't
address the entire 64-bit physical address space.  Therefore, we only
allocate top-down if the arch requests it by clearing
"resource_alloc_from_bottom".

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-10-26 15:33:31 -07:00
Bjorn Helgaas
a1862e3107 resources: handle overflow when aligning start of available area
If tmp.start is near ~0, ALIGN(tmp.start) may overflow, which would
make us think there's more available space than there really is.  We
would likely return something that conflicts with a previous resource,
which would cause a failure when allocate_resource() requests the newly-
allocated region.

Reference: https://bugzilla.redhat.com/show_bug.cgi?id=646027
Reported-by: Fabrice Bellet <fabrice@bellet.info>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-10-26 15:33:28 -07:00
Bjorn Helgaas
6909ba14c2 resources: ensure callback doesn't allocate outside available space
The alignment callback returns a proposed location, which may have been
adjusted to avoid ISA aliases or for other architecture-specific reasons.

We already had a check ("tmp.start < tmp.end") to make sure the callback
doesn't return an area that extends past the available area.  This patch
reworks the check to make sure it doesn't return an area that extends
either below or above the available area.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-10-26 15:33:26 -07:00
Bjorn Helgaas
5d6b1fa301 resources: factor out resource_clip() to simplify find_resource()
This factors out the min/max clipping to simplify find_resource().
No functional change.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-10-26 15:33:24 -07:00
Bjorn Helgaas
a9cea01741 resources: add a default alignf to simplify find_resource()
This removes a test from find_resource(), which is getting cluttered.
No functional change.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-10-26 15:33:22 -07:00
Ingo Molnar
5c16d2c813 Merge branch 'tip/perf/ringbuffer-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent 2010-10-26 13:14:02 +02:00
Christoph Hellwig
312d3ca856 fs: use percpu counter for nr_dentry and nr_dentry_unused
The nr_dentry stat is a globally touched cacheline and atomic operation
twice over the lifetime of a dentry. It is used for the benfit of userspace
only. Turn it into a per-cpu counter and always decrement it in d_free instead
of doing various batching operations to reduce lock hold times in the callers.

Based on an earlier patch from Nick Piggin <npiggin@suse.de>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:12 -04:00
Christoph Hellwig
85fe4025c6 fs: do not assign default i_ino in new_inode
Instead of always assigning an increasing inode number in new_inode
move the call to assign it into those callers that actually need it.
For now callers that need it is estimated conservatively, that is
the call is added to all filesystems that do not assign an i_ino
by themselves.  For a few more filesystems we can avoid assigning
any inode number given that they aren't user visible, and for others
it could be done lazily when an inode number is actually needed,
but that's left for later patches.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:11 -04:00
Al Viro
7de9c6ee3e new helper: ihold()
Clones an existing reference to inode; caller must already hold one.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:11 -04:00
Dave Chinner
cffbc8aa33 fs: Convert nr_inodes and nr_unused to per-cpu counters
The number of inodes allocated does not need to be tied to the
addition or removal of an inode to/from a list. If we are not tied
to a list lock, we could update the counters when inodes are
initialised or destroyed, but to do that we need to convert the
counters to be per-cpu (i.e. independent of a lock). This means that
we have the freedom to change the list/locking implementation
without needing to care about the counters.

Based on a patch originally from Eric Dumazet.

[AV: cleaned up a bit, fixed build breakage on weird configs

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:09 -04:00
Eric Dumazet
7e360c38ab fs: allow for more than 2^31 files
Andrew,

Could you please review this patch, you probably are the right guy to
take it, because it crosses fs and net trees.

Note : /proc/sys/fs/file-nr is a read-only file, so this patch doesnt
depend on previous patch (sysctl: fix min/max handling in
__do_proc_doulongvec_minmax())

Thanks !

[PATCH V4] fs: allow for more than 2^31 files

Robin Holt tried to boot a 16TB system and found af_unix was overflowing
a 32bit value :

<quote>

We were seeing a failure which prevented boot.  The kernel was incapable
of creating either a named pipe or unix domain socket.  This comes down
to a common kernel function called unix_create1() which does:

        atomic_inc(&unix_nr_socks);
        if (atomic_read(&unix_nr_socks) > 2 * get_max_files())
                goto out;

The function get_max_files() is a simple return of files_stat.max_files.
files_stat.max_files is a signed integer and is computed in
fs/file_table.c's files_init().

        n = (mempages * (PAGE_SIZE / 1024)) / 10;
        files_stat.max_files = n;

In our case, mempages (total_ram_pages) is approx 3,758,096,384
(0xe0000000).  That leaves max_files at approximately 1,503,238,553.
This causes 2 * get_max_files() to integer overflow.

</quote>

Fix is to let /proc/sys/fs/file-nr & /proc/sys/fs/file-max use long
integers, and change af_unix to use an atomic_long_t instead of
atomic_t.

get_max_files() is changed to return an unsigned long.
get_nr_files() is changed to return a long.

unix_nr_socks is changed from atomic_t to atomic_long_t, while not
strictly needed to address Robin problem.

Before patch (on a 64bit kernel) :
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
-18446744071562067968

After patch:
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
2147483648
# cat /proc/sys/fs/file-nr
704     0       2147483648

Reported-by: Robin Holt <holt@sgi.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David Miller <davem@davemloft.net>
Reviewed-by: Robin Holt <holt@sgi.com>
Tested-by: Robin Holt <holt@sgi.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:18:20 -04:00
David Howells
5260562754 MN10300: Fix the PERCPU() alignment to allow for workqueues
In the MN10300 arch, we occasionally see an assertion being tripped in
alloc_cwqs() at the following line:

        /* just in case, make sure it's actually aligned */
  --->  BUG_ON(!IS_ALIGNED(wq->cpu_wq.v, align));
        return wq->cpu_wq.v ? 0 : -ENOMEM;

The values are:

        wa->cpu_wq.v => 0x902776e0
        align => 0x100

and align is calculated by the following:

        const size_t align = max_t(size_t, 1 << WORK_STRUCT_FLAG_BITS,
                                   __alignof__(unsigned long long));

This is because the pointer in question (wq->cpu_wq.v) loses some of its
lower bits to control flags, and so the object it points to must be
sufficiently aligned to avoid the need to use those bits for pointing to
things.

Currently, 4 control bits and 4 colour bits are used in normal
circumstances, plus a debugging bit if debugging is set.  This requires
the cpu_workqueue_struct struct to be at least 256 bytes aligned (or 512
bytes aligned with debugging).

PERCPU() alignment on MN13000, however, is only 32 bytes as set in
vmlinux.lds.S.  So we set this to PAGE_SIZE (4096) to match most other
arches and stick a comment in alloc_cwqs() for anyone else who triggers
the assertion.

Reported-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Mark Salter <msalter@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-25 16:24:06 -07:00
Masami Hiramatsu
43948f5027 kprobes: Remove redundant text_mutex lock in optimize
Remove text_mutex locking in optimize_all_kprobes, because
this function doesn't modify text. It simply queues probes on
optimization list for kprobe_optimizer worker thread.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101025131801.19160.70939.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-25 15:51:55 +02:00
Linus Torvalds
229aebb873 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  Update broken web addresses in arch directory.
  Update broken web addresses in the kernel.
  Revert "drivers/usb: Remove unnecessary return's from void functions" for musb gadget
  Revert "Fix typo: configuation => configuration" partially
  ida: document IDA_BITMAP_LONGS calculation
  ext2: fix a typo on comment in ext2/inode.c
  drivers/scsi: Remove unnecessary casts of private_data
  drivers/s390: Remove unnecessary casts of private_data
  net/sunrpc/rpc_pipe.c: Remove unnecessary casts of private_data
  drivers/infiniband: Remove unnecessary casts of private_data
  drivers/gpu/drm: Remove unnecessary casts of private_data
  kernel/pm_qos_params.c: Remove unnecessary casts of private_data
  fs/ecryptfs: Remove unnecessary casts of private_data
  fs/seq_file.c: Remove unnecessary casts of private_data
  arm: uengine.c: remove C99 comments
  arm: scoop.c: remove C99 comments
  Fix typo configue => configure in comments
  Fix typo: configuation => configuration
  Fix typo interrest[ing|ed] => interest[ing|ed]
  Fix various typos of valid in comments
  ...

Fix up trivial conflicts in:
	drivers/char/ipmi/ipmi_si_intf.c
	drivers/usb/gadget/rndis.c
	net/irda/irnet/irnet_ppp.c
2010-10-24 13:41:39 -07:00
Rakib Mullick
d4a6f3c32c sched_stat: Update sched_info_queue/dequeue() code comments
Remove some sched_info_queue(), sched_info_dequeue() code comment.
We no longer belongs to the era of O(1) and we don't use active or expired
array anymore.

Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <AANLkTi=REu0WzOp5N=nVT1=ZJ=ZA+MZFV+4CHSJ3Q-Yv@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-24 13:29:01 +02:00
Joe Perches
aa7b250c25 tracing: Fix 'faild' -> 'failed' typo
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Kosina <trivial@kernel.org>
LKML-Reference: <cd9855af60d7d90e9f55fc7afd0ed23fcdaa6f52.1287724261.git.joe@perches.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-23 20:06:38 +02:00
Ingo Molnar
b8ecad8b2f Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux-2.6 into perf/urgent 2010-10-23 20:05:43 +02:00
Linus Torvalds
02f36038c5 Merge branches 'softirq-for-linus', 'x86-debug-for-linus', 'x86-numa-for-linus', 'x86-quirks-for-linus', 'x86-setup-for-linus', 'x86-uv-for-linus' and 'x86-vm86-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'softirq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  softirqs: Make wakeup_softirqd static

* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, asm: Restore parentheses around one pushl_cfi argument
  x86, asm: Fix ancient-GAS workaround
  x86, asm: Fix CFI macro invocations to deal with shortcomings in gas

* 'x86-numa-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, numa: Assign CPUs to nodes in round-robin manner on fake NUMA

* 'x86-quirks-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: HPET force enable for CX700 / VIA Epia LT

* 'x86-setup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, setup: Use string copy operation to optimze copy in kernel compression

* 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, UV: Use allocated buffer in tlb_uv.c:tunables_read()

* 'x86-vm86-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, vm86: Fix preemption bug for int1 debug and int3 breakpoint handlers.
2010-10-23 08:25:36 -07:00
Linus Torvalds
8814011679 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
  kdb,debug_core: adjust master cpu switch logic against new debug_core locking
  debug_core: refactor locking for master/slave cpus
  x86,kgdb: remove unnecessary call to kgdb_correct_hw_break()
  debug_core: disable hw_breakpoints on all cores in kgdb_cpu_enter()
  kdb,kgdb: fix sparse fixups
  kdb: Fix oops in kdb_unregister
  kdb,ftdump: Remove reference to internal kdb include
  kdb: Allow kernel loadable modules to add kdb shell functions
  debug_core: stop rcu warnings on kernel resume
  debug_core: move all watch dog syncs to a single function
  x86,kgdb: fix debugger hw breakpoint test regression in 2.6.35
2010-10-22 20:35:12 -07:00
Linus Torvalds
91b745016c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: remove in_workqueue_context()
  workqueue: Clarify that schedule_on_each_cpu is synchronous
  memory_hotplug: drop spurious calls to flush_scheduled_work()
  shpchp: update workqueue usage
  pciehp: update workqueue usage
  isdn/eicon: don't call flush_scheduled_work() from diva_os_remove_soft_isr()
  workqueue: add and use WQ_MEM_RECLAIM flag
  workqueue: fix HIGHPRI handling in keep_working()
  workqueue: add queue_work and activate_work trace points
  workqueue: prepare for more tracepoints
  workqueue: implement flush[_delayed]_work_sync()
  workqueue: factor out start_flush_work()
  workqueue: cleanup flush/cancel functions
  workqueue: implement alloc_ordered_workqueue()

Fix up trivial conflict in fs/gfs2/main.c as per Tejun
2010-10-22 17:13:10 -07:00
Jason Wessel
495363d380 kdb,debug_core: adjust master cpu switch logic against new debug_core locking
The kdb shell needs to enforce switching back to the original CPU that
took the exception before restoring normal kernel execution.  Resuming
from a different CPU than what took the original exception will cause
problems with spin locks that are freed from the a different processor
than had taken the lock.

The special logic in dbg_cpu_switch() can go away entirely with
because the state of what cpus want to be masters or slaves will
remain unchanged between entry and exit of the debug_core exception
context.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-22 15:34:13 -05:00
Jason Wessel
dfee3a7b92 debug_core: refactor locking for master/slave cpus
For quite some time there have been problems with memory barriers and
various races with NMI on multi processor systems using the kernel
debugger.  The algorithm for entering the kernel debug core and
resuming kernel execution was racy and had several known edge case
problems with attempting to debug something on a heavily loaded system
using breakpoints that are hit repeatedly and quickly.

The prior "locking" design entry worked as follows:

  * The atomic counter kgdb_active was used with atomic exchange in
    order to elect a master cpu out of all the cpus that may have
    taken a debug exception.
  * The master cpu increments all elements of passive_cpu_wait[].
  * The master cpu issues the round up cpus message.
  * Each "slave cpu" that enters the debug core increments its own
    element in cpu_in_kgdb[].
  * Each "slave cpu" spins on passive_cpu_wait[] until it becomes 0.
  * The master cpu debugs the system.

The new scheme removes the two arrays of atomic counters and replaces
them with 2 single counters.  One counter is used to count the number
of cpus waiting to become a master cpu (because one or more hit an
exception). The second counter is use to indicate how many cpus have
entered as slave cpus.

The new entry logic works as follows:

  * One or more cpus enters via kgdb_handle_exception() and increments
    the masters_in_kgdb. Each cpu attempts to get the spin lock called
    dbg_master_lock.
  * The master cpu sets kgdb_active to the current cpu.
  * The master cpu takes the spinlock dbg_slave_lock.
  * The master cpu asks to round up all the other cpus.
  * Each slave cpu that is not already in kgdb_handle_exception()
    will enter and increment slaves_in_kgdb.  Each slave will now spin
    try_locking on dbg_slave_lock.
  * The master cpu waits for the sum of masters_in_kgdb and slaves_in_kgdb
    to be equal to the sum of the online cpus.
  * The master cpu debugs the system.

In the new design the kgdb_active can only be changed while holding
dbg_master_lock.  Stress testing has not turned up any further
entry/exit races that existed in the prior locking design.  The prior
locking design suffered from atomic variables not being truly atomic
(in the capacity as used by kgdb) along with memory barrier races.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Dongdong Deng <dongdong.deng@windriver.com>
2010-10-22 15:34:13 -05:00
Dongdong Deng
c1bb9a9c19 debug_core: disable hw_breakpoints on all cores in kgdb_cpu_enter()
The slave cpus do not have the hw breakpoints disabled upon entry to
the debug_core and as a result could cause unrecoverable recursive
faults on badly placed breakpoints, or get out of sync with the arch
specific hw breakpoint operations.

This patch addresses the problem by invoking kgdb_disable_hw_debug()
earlier in kgdb_enter_cpu for each cpu that enters the debug core.

The hw breakpoint dis/enable flow should be:

master_debug_cpu   slave_debug_cpu
         \              /
          kgdb_cpu_enter
                |
        kgdb_disable_hw_debug --> uninstall pre-enabled hw_breakpoint
                |
 do add/rm dis/enable operates to hw_breakpoints on master_debug_cpu..
                |
        correct_hw_break --> correct/install the enabled hw_breakpoint
                |
           leave_kgdb

Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-22 15:34:12 -05:00
Jason Wessel
91b152aa85 kdb,kgdb: fix sparse fixups
Fix the following sparse warnings:

kdb_main.c:328:5: warning: symbol 'kdbgetu64arg' was not declared. Should it be static?
kgdboc.c:246:12: warning: symbol 'kgdboc_early_init' was not declared. Should it be static?
kgdb.c:652:26: warning: incorrect type in argument 1 (different address spaces)
kgdb.c:652:26:    expected void const *ptr
kgdb.c:652:26:    got struct perf_event *[noderef] <asn:3>*pev

The one in kgdb.c required the (void * __force) because of the return
code from register_wide_hw_breakpoint looking like:

        return (void __percpu __force *)ERR_PTR(err);

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-22 15:34:12 -05:00
Jason Wessel
75d14edee5 kdb: Fix oops in kdb_unregister
Nothing should try to use kdb_commands directly as sometimes it is
null.  Instead, use the for_each_kdbcmd() iterator.

This particular problem dates back to the initial kdb merge (2.6.35),
but at that point nothing was dynamically unregistering commands from
the kdb shell.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-22 15:34:12 -05:00
Jason Wessel
e3bda3ac33 kdb,ftdump: Remove reference to internal kdb include
Now that include/linux/kdb.h properly exports all the functions
required to dynamically add a kdb shell command, the reference to the
private kdb header can be removed.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-22 15:34:11 -05:00
Jason Wessel
f7030bbc44 kdb: Allow kernel loadable modules to add kdb shell functions
In order to allow kernel modules to dynamically add a command to the
kdb shell the kdb_register, kdb_register_repeat, kdb_unregister, and
kdb_printf need to be exported as GPL symbols.

Any kernel module that adds a dynamic kdb shell function should only
need to include linux/kdb.h.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-22 15:34:11 -05:00