Commit Graph

278 Commits

Author SHA1 Message Date
Rafael J. Wysocki
e00e56dfd3 cpufreq: Use syscore_ops for boot CPU suspend/resume (v2)
The cpufreq subsystem uses sysdev suspend and resume for
executing cpufreq_suspend() and cpufreq_resume(), respectively,
during system suspend, after interrupts have been switched off on the
boot CPU, and during system resume, while interrupts are still off on
the boot CPU.  In both cases the other CPUs are off-line at the
relevant point (either they have been switched off via CPU hotplug
during suspend, or they haven't been switched on yet during resume).
For this reason, although it may seem that cpufreq_suspend() and
cpufreq_resume() are executed for all CPUs in the system, they are
only called for the boot CPU in fact, which is quite confusing.

To remove the confusion and to prepare for elimiating sysdev
suspend and resume operations from the kernel enirely, convernt
cpufreq to using a struct syscore_ops object for the boot CPU
suspend and resume and rename the callbacks so that their names
reflect their purpose.  In addition, put some explanatory remarks
into their kerneldoc comments.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-23 22:16:32 +01:00
Rafael J. Wysocki
7ca64e2d28 [CPUFREQ] Remove the pm_message_t argument from driver suspend
None of the existing cpufreq drivers uses the second argument of
its .suspend() callback (which isn't useful anyway), so remove it.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Dave Jones <davej@redhat.com>
2011-03-16 17:54:33 -04:00
Thomas Renninger
326c86deae [CPUFREQ] Remove unneeded locks
There cannot be any concurrent access to these through
different cpu sysfs files anymore, because these tunables
are now all global (not per cpu).

I still have some doubts whether some of these locks
were needed at all. Anyway, let's get rid of them.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
CC: cpufreq@vger.kernel.org
2011-03-16 17:54:32 -04:00
Thomas Renninger
e8951251b8 [CPUFREQ] Remove old, deprecated per cpu ondemand/conservative sysfs files
Marked deprecated for quite a whilte now...

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
CC: cpufreq@vger.kernel.org
2011-03-16 17:54:32 -04:00
Thomas Renninger
ef598549b2 [CPUFREQ] Remove deprecated sysfs file sampling_rate_max
Marked deprecated for quite a while now...

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
CC: cpufreq@vger.kernel.org
2011-03-16 17:54:32 -04:00
Vincent Guittot
5cb2c3bd0c [CPUFREQ] calculate delay after dbs_check_cpu
calculate ondemand delay after dbs_check_cpu call because it can
modify rate_mult value

use freq_lo_jiffies value for the sub sample period of powersave_bias mode

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Dave Jones <davej@redhat.com>
2011-03-16 17:54:31 -04:00
Joe Perches
2feb690c20 [CPUFREQ] drivers/cpufreq: Remove unnecessary semicolons
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2011-03-16 17:54:31 -04:00
Linus Torvalds
bd2895eead Merge branch 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
* 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: fix build failure introduced by s/freezeable/freezable/
  workqueue: add system_freezeable_wq
  rds/ib: use system_wq instead of rds_ib_fmr_wq
  net/9p: replace p9_poll_task with a work
  net/9p: use system_wq instead of p9_mux_wq
  xfs: convert to alloc_workqueue()
  reiserfs: make commit_wq use the default concurrency level
  ocfs2: use system_wq instead of ocfs2_quota_wq
  ext4: convert to alloc_workqueue()
  scsi/scsi_tgt_lib: scsi_tgtd isn't used in memory reclaim path
  scsi/be2iscsi,qla2xxx: convert to alloc_workqueue()
  misc/iwmc3200top: use system_wq instead of dedicated workqueues
  i2o: use alloc_workqueue() instead of create_workqueue()
  acpi: kacpi*_wq don't need WQ_MEM_RECLAIM
  fs/aio: aio_wq isn't used in memory reclaim path
  input/tps6507x-ts: use system_wq instead of dedicated workqueue
  cpufreq: use system_wq instead of dedicated workqueues
  wireless/ipw2x00: use system_wq instead of dedicated workqueues
  arm/omap: use system_wq in mailbox
  workqueue: use WQ_MEM_RECLAIM instead of WQ_RESCUER
2011-03-16 08:20:19 -07:00
Jiri Slaby
8f5bc2abfd [CPUFREQ] fix BUG on cpufreq policy init failure
cpufreq_register_driver sets cpufreq_driver to a structure owned (and
placed) in the caller's memory. If cpufreq policy fails in its ->init
function, sysdev_driver_register returns nonzero in
cpufreq_register_driver. Now, cpufreq_register_driver returns an error
without setting cpufreq_driver back to NULL.

Usually cpufreq policy modules are unloaded because they propagate the
error to the module init function and return that.

So a later access to any member of cpufreq_driver causes bugs like:
BUG: unable to handle kernel paging request at ffffffffa00270a0
IP: [<ffffffff8145eca3>] cpufreq_cpu_get+0x53/0xe0
PGD 1805067 PUD 1809063 PMD 1c3f90067 PTE 0
Oops: 0000 [#1] SMP
last sysfs file: /sys/devices/virtual/net/tun0/statistics/collisions
CPU 0
Modules linked in: ...
Pid: 5677, comm: thunderbird-bin Tainted: G        W   2.6.38-rc4-mm1_64+ #1389 To be filled by O.E.M./To Be Filled By O.E.M.
RIP: 0010:[<ffffffff8145eca3>]  [<ffffffff8145eca3>] cpufreq_cpu_get+0x53/0xe0
RSP: 0018:ffff8801aec37d98  EFLAGS: 00010086
RAX: 0000000000000202 RBX: 0000000000000000 RCX: 0000000000000001
RDX: ffffffffa00270a0 RSI: 0000000000001000 RDI: ffffffff8199ece8
...
Call Trace:
 [<ffffffff8145f490>] cpufreq_quick_get+0x10/0x30
 [<ffffffff8103f12b>] show_cpuinfo+0x2ab/0x300
 [<ffffffff81136292>] seq_read+0xf2/0x3f0
 [<ffffffff8126c5d3>] ? __strncpy_from_user+0x33/0x60
 [<ffffffff8116850d>] proc_reg_read+0x6d/0xa0
 [<ffffffff81116e53>] vfs_read+0xc3/0x180
 [<ffffffff81116f5c>] sys_read+0x4c/0x90
 [<ffffffff81030dbb>] system_call_fastpath+0x16/0x1b
...

It's all cause by weird fail path handling in cpufreq_register_driver.
To fix that, shuffle the code to do proper handling with gotos.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Dave Jones <davej@redhat.com>
2011-03-01 18:49:44 -05:00
Tejun Heo
57df5573a5 cpufreq: use system_wq instead of dedicated workqueues
With cmwq, there's no reason for cpufreq drivers to use separate
workqueues.  Remove the dedicated workqueues from cpufreq_conservative
and cpufreq_ondemand and use system_wq instead.  The work items are
already sync canceled on stop, so it's already guaranteed that no work
is running on module exit.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Dave Jones <davej@redhat.com>
Cc: cpufreq@vger.kernel.org
2011-01-26 12:12:50 +01:00
David Rientjes
6a108a14fa kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT
The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option
is used to configure any non-standard kernel with a much larger scope than
only small devices.

This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes
references to the option throughout the kernel.  A new CONFIG_EMBEDDED
option is added that automatically selects CONFIG_EXPERT when enabled and
can be used in the future to isolate options that should only be
considered for embedded systems (RISC architectures, SLOB, etc).

Calling the option "EXPERT" more accurately represents its intention: only
expert users who understand the impact of the configuration changes they
are making should enable it.

Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: David Woodhouse <david.woodhouse@intel.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Greg KH <gregkh@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Robin Holt <holt@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-20 17:02:05 -08:00
Thomas Renninger
25e41933b5 perf: Clean up power events by introducing new, more generic ones
Add these new power trace events:

 power:cpu_idle
 power:cpu_frequency
 power:machine_suspend

The old C-state/idle accounting events:
  power:power_start
  power:power_end

Have now a replacement (but we are still keeping the old
tracepoints for compatibility):

  power:cpu_idle

and
  power:power_frequency

is replaced with:
  power:cpu_frequency

power:machine_suspend is newly introduced.

Jean Pihet has a patch integrated into the generic layer
(kernel/power/suspend.c) which will make use of it.

the type= field got removed from both, it was never
used and the type is differed by the event type itself.

perf timechart userspace tool gets adjusted in a separate patch.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Jean Pihet <jean.pihet@newoldbits.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: rjw@sisk.pl
LKML-Reference: <1294073445-14812-3-git-send-email-trenn@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <1290072314-31155-2-git-send-email-trenn@suse.de>
2011-01-04 08:16:54 +01:00
David C Niemi
3f78a9f7fc [CPUFREQ] add sampling_down_factor tunable to improve ondemand performance
Adds a new global tunable, sampling_down_factor.  Set to 1 it makes no
changes from existing behavior, but set to greater than 1 (e.g. 100)
it acts as a multiplier for the scheduling interval for reevaluating
load when the CPU is at its top speed due to high load.  This improves
performance by reducing the overhead of load evaluation and helping
the CPU stay at its top speed when truly busy, rather than shifting
back and forth in speed.  This tunable has no effect on behavior at
lower speeds/lower CPU loads.

This patch is against 2.6.36-rc6.

This patch should help solve kernel bug 19672 "ondemand is slow".

Signed-off-by: David Niemi <dniemi@verisign.com>
Acked-by: Venkatesh Pallipadi <venki@google.com>
CC: Daniel Hollocher <danielhollocher@gmail.com>
CC: <cpufreq-list@vger.kernel.org>
CC: <linux-kernel@vger.kernel.org>
Signed-off-by: Dave Jones <davej@redhat.com>
2010-10-22 11:44:47 -04:00
Julia Lawall
bec037aa6c [CPUFREQ] drivers/cpufreq: Adjust confusing if indentation
Indent the body of for_each_cpu.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r disable braces4@
position p1,p2;
statement S1,S2;
@@

(
if (...) { ... }
|
if (...) S1@p1 S2@p2
)

@script:python@
p1 << r.p1;
p2 << r.p2;
@@

if (p1[0].column == p2[0].column):
  cocci.print_main("branch",p1)
  cocci.print_secs("after",p2)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Dave Jones <davej@redhat.com>
2010-10-22 11:44:47 -04:00
Neal Buckendahl
9c36f746d7 [CPUFREQ] fix brace coding style issue.
This patch fixes up a brace warning found by the checkpatch.pl tool

Signed-off-by: Neal Buckendahl <nealb001@tbcnet.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2010-08-03 13:47:05 -04:00
Thomas Renninger
6f4f2723d0 [CPUFREQ] x86 cpufreq: Make trace_power_frequency cpufreq driver independent
and fix the broken case if a core's frequency depends on others.

trace_power_frequency was only implemented in a rather ungeneric way
in acpi-cpufreq driver's target() function only.
-> Move the call to trace_power_frequency to
   cpufreq.c:cpufreq_notify_transition() where CPUFREQ_POSTCHANGE
   notifier is triggered.
   This will support power frequency tracing by all cpufreq drivers

trace_power_frequency did not trace frequency changes correctly when
the userspace governor was used or when CPU cores' frequency depend
on each other.
-> Moving this into the CPUFREQ_POSTCHANGE notifier and pass the cpu
   which gets switched automatically fixes this.

Robert Schoene provided some important fixes on top of my initial
quick shot version which are integrated in this patch:
- Forgot some changes in power_end trace (TP_printk/variable names)
- Variable dummy in power_end must now be cpu_id
- Use static 64 bit variable instead of unsigned int for cpu_id

Signed-off-by: Thomas Renninger <trenn@suse.de>
CC: davej@redhat.com
CC: arjan@infradead.org
CC: linux-kernel@vger.kernel.org
CC: robert.schoene@tu-dresden.de
Tested-by: robert.schoene@tu-dresden.de
Signed-off-by: Dave Jones <davej@redhat.com>
2010-08-03 13:47:05 -04:00
Jocelyn Falempe
a665df9d51 [CPUFREQ] ondemand: don't synchronize sample rate unless multiple cpus present
For UP systems this is not required, and results in a more consistent
sample interval.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jocelyn Falempe <jocelyn.falempe@motorola.com>
Signed-off-by: Mike Chan <mike@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Jones <davej@redhat.com>
2010-08-03 13:47:04 -04:00
Amerigo Wang
226528c610 [CPUFREQ] unexport (un)lock_policy_rwsem* functions
lock_policy_rwsem_* and unlock_policy_rwsem_* functions are scheduled
to be unexported when 2.6.33. Now there are no other callers of them
out of cpufreq.c, unexport them and make them static.

Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2010-08-03 13:47:04 -04:00
Mike Chan
00e299fff3 [CPUFREQ] ondemand: Refactor frequency increase code
Make simpler to read and call.

*** v3 - Always call when powersave_bias is enabled.

Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Mike Chan <mike@android.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2010-08-03 13:47:04 -04:00
Xiaotian Feng
cad70a6ae5 [CPUFREQ] fix memory leak in cpufreq_add_dev
We didn't free policy->related_cpus in error path err_unlock_policy.
This is catched by following kmemleak report:

unreferenced object 0xffff88022a0b96d0 (size 512):
  comm "modprobe", pid 886, jiffies 4294689177 (age 780.694s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff8111ebe5>] create_object+0x186/0x281
    [<ffffffff814fad4f>] kmemleak_alloc+0x60/0xa7
    [<ffffffff8111127a>] kmem_cache_alloc_node_notrace+0x120/0x142
    [<ffffffff81262e4f>] alloc_cpumask_var_node+0x2c/0xd7
    [<ffffffff81262f0b>] alloc_cpumask_var+0x11/0x13
    [<ffffffff81262f1c>] zalloc_cpumask_var+0xf/0x11
    [<ffffffff8140fac0>] cpufreq_add_dev+0x11f/0x547
    [<ffffffff81334bda>] sysdev_driver_register+0xc2/0x11d
    [<ffffffff8140e334>] cpufreq_register_driver+0xcb/0x1b8
    [<ffffffffa032e040>] 0xffffffffa032e040
    [<ffffffff810021ba>] do_one_initcall+0x5e/0x15c
    [<ffffffff81087f94>] sys_init_module+0xa6/0x1e6
    [<ffffffff81009bc2>] system_call_fastpath+0x16/0x1b
    [<ffffffffffffffff>] 0xffffffffffffffff

Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Cc: Thomas Renninger <trenn@suse.de>
Cc: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2010-08-03 13:47:02 -04:00
Andrej Gelenberg
ffe6275f90 [CPUFREQ] revert "[CPUFREQ] remove rwsem lock from CPUFREQ_GOV_STOP call (second call site)"
395913d0b1 ("[CPUFREQ] remove rwsem lock
from CPUFREQ_GOV_STOP call (second call site)") is not needed, because
there is no rwsem lock in cpufreq_ondemand and cpufreq_conservative
anymore.  Lock should not be released until the work done.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=1594

Signed-off-by: Andrej Gelenberg <andrej.gelenberg@udo.edu>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2010-08-03 13:47:01 -04:00
Linus Torvalds
07d77759c9 Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, hypervisor: add missing <linux/module.h>
  Modify the VMware balloon driver for the new x86_hyper API
  x86, hypervisor: Export the x86_hyper* symbols
  x86: Clean up the hypervisor layer
  x86, HyperV: fix up the license to mshyperv.c
  x86: Detect running on a Microsoft HyperV system
  x86, cpu: Make APERF/MPERF a normal table-driven flag
  x86, k8: Fix build error when K8_NB is disabled
  x86, cacheinfo: Disable index in all four subcaches
  x86, cacheinfo: Make L3 cache info per node
  x86, cacheinfo: Reorganize AMD L3 cache structure
  x86, cacheinfo: Turn off L3 cache index disable feature in virtualized environments
  x86, cacheinfo: Unify AMD L3 cache index disable checking
  cpufreq: Unify sysfs attribute definition macros
  powernow-k8: Fix frequency reporting
  x86, cpufreq: Add APERF/MPERF support for AMD processors
  x86: Unify APERF/MPERF support
  powernow-k8: Add core performance boost support
  x86, cpu: Add AMD core boosting feature flag to /proc/cpuinfo

Fix up trivial conflicts in arch/x86/kernel/cpu/intel_cacheinfo.c and
drivers/cpufreq/cpufreq_ondemand.c
2010-05-18 08:49:13 -07:00
Arjan van de Ven
19379b1181 ondemand: Make the iowait-is-busy time a sysfs tunable
Pavel Machek pointed out that not all CPUs have an efficient
idle at high frequency. Specifically, older Intel and various
AMD cpus would get a higher powerusage when copying files from
USB.

Mike Chan pointed out that the same is true for various ARM
chips as well.

Thomas Renninger suggested to make this a sysfs tunable with a
reasonable default.

This patch adds a sysfs tunable for the new behavior, and uses
a very simple function to determine a reasonable default,
depending on the CPU vendor/type.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: davej@redhat.com
LKML-Reference: <20100509082651.46914d04@infradead.org>
[ minor tidyup ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-09 19:35:27 +02:00
Arjan van de Ven
6b8fcd9029 ondemand: Solve a big performance issue by counting IOWAIT time as busy
The ondemand cpufreq governor uses CPU busy time (e.g. not-idle
time) as a measure for scaling the CPU frequency up or down.
If the CPU is busy, the CPU frequency scales up, if it's idle,
the CPU frequency scales down. Effectively, it uses the CPU busy
time as proxy variable for the more nebulous "how critical is
performance right now" question.

This algorithm falls flat on its face in the light of workloads
where you're alternatingly disk and CPU bound, such as the ever
popular "git grep", but also things like startup of programs and
maildir using email clients... much to the chagarin of Andrew
Morton.

This patch changes the ondemand algorithm to count iowait time
as busy, not idle, time. As shown in the breakdown cases above,
iowait is performance critical often, and by counting iowait,
the proxy variable becomes a more accurate representation of the
"how critical is performance" question.

The problem and fix are both verified with the "perf timechar"
tool.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Jones <davej@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100509082606.3d9f00d0@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-09 19:35:27 +02:00
H. Peter Anvin
d7be0ce6af Merge commit 'v2.6.34-rc6' into x86/cpu 2010-05-08 14:59:58 -07:00
Linus Torvalds
ddc9b34c3b Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
  [CPUFREQ] use max load in conservative governor
  [CPUFREQ] fix a lockdep warning
2010-04-24 11:35:21 -07:00
Borislav Petkov
6dad2a2964 cpufreq: Unify sysfs attribute definition macros
Multiple modules used to define those which are with identical
functionality and were needlessly replicated among the different cpufreq
drivers. Push them into the header and remove duplication.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <1270065406-1814-7-git-send-email-bp@amd64.org>
Reviewed-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-04-09 14:07:56 -07:00
Dominik Brodowski
fd187aaf98 [CPUFREQ] use max load in conservative governor
Instead of using the load of the last CPU in a package, use the
maximum load of all CPUs in a package.

Reported-by: Jean-Christian Goussard <jeanchristian.goussard@sfr.fr>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Dave Jones <davej@redhat.com>
2010-03-31 12:00:22 -04:00
Amerigo Wang
499bca9b6d [CPUFREQ] fix a lockdep warning
There is no need to do sysfs_remove_link() or kobject_put() etc.
when policy_rwsem_write is held, move them after releasing the lock.

This fixes the lockdep warning:

halt/4071 is trying to acquire lock:
 (s_active){++++.+}, at: [<c0000000001ef868>] .sysfs_addrm_finish+0x58/0xc0

but task is already holding lock:
 (&per_cpu(cpu_policy_rwsem, cpu)){+.+.+.}, at: [<c0000000004cd6ac>] .lock_policy_rwsem_write+0x84/0xf4

Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2010-03-31 12:00:21 -04:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Emese Revfy
52cf25d0ab Driver core: Constify struct sysfs_ops in struct kobj_type
Constify struct sysfs_ops.

This is part of the ops structure constification
effort started by Arjan van de Ven et al.

Benefits of this constification:

 * prevents modification of data that is shared
   (referenced) by many other structure instances
   at runtime

 * detects/prevents accidental (but not intentional)
   modification attempts on archs that enforce
   read-only kernel data at runtime

 * potentially better optimized code as the compiler
   can assume that the const data cannot be changed

 * the compiler/linker move const data into .rodata
   and therefore exclude them from false sharing

Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: David Teigland <teigland@redhat.com>
Acked-by: Matt Domsch <Matt_Domsch@dell.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Hans J. Koch <hjk@linutronix.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07 17:04:49 -08:00
Nagananda.Chumbalkar@hp.com
1dbf58881f [CPUFREQ] Fix ondemand to not request targets outside policy limits
Dominik said:
target_freq cannot be below policy->min or above policy->max.
If it were, the whole cpufreq subsystem is broken.

But (answer):
I think the "ondemand" governor can ask for a target frequency that is
below policy->min.
...
A patch such as below may be needed to sanitize the target frequency
requested by "ondemand". The "conservative" governor already has this check:

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>

# diff -bur x/drivers/cpufreq/cpufreq_ondemand.c.orig y/drivers/cpufreq/cpufreq_ondemand.c
2010-01-13 10:55:16 -05:00
Linus Torvalds
d0316554d3 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (34 commits)
  m68k: rename global variable vmalloc_end to m68k_vmalloc_end
  percpu: add missing per_cpu_ptr_to_phys() definition for UP
  percpu: Fix kdump failure if booted with percpu_alloc=page
  percpu: make misc percpu symbols unique
  percpu: make percpu symbols in ia64 unique
  percpu: make percpu symbols in powerpc unique
  percpu: make percpu symbols in x86 unique
  percpu: make percpu symbols in xen unique
  percpu: make percpu symbols in cpufreq unique
  percpu: make percpu symbols in oprofile unique
  percpu: make percpu symbols in tracer unique
  percpu: make percpu symbols under kernel/ and mm/ unique
  percpu: remove some sparse warnings
  percpu: make alloc_percpu() handle array types
  vmalloc: fix use of non-existent percpu variable in put_cpu_var()
  this_cpu: Use this_cpu_xx in trace_functions_graph.c
  this_cpu: Use this_cpu_xx for ftrace
  this_cpu: Use this_cpu_xx in nmi handling
  this_cpu: Use this_cpu operations in RCU
  this_cpu: Use this_cpu ops for VM statistics
  ...

Fix up trivial (famous last words) global per-cpu naming conflicts in
	arch/x86/kvm/svm.c
	mm/slab.c
2009-12-14 09:58:24 -08:00
Thomas Renninger
e2f74f355e [ACPI/CPUFREQ] Introduce bios_limit per cpu cpufreq sysfs interface
This interface is mainly intended (and implemented) for ACPI _PPC BIOS
frequency limitations, but other cpufreq drivers can also use it for
similar use-cases.

Why is this needed:

Currently it's not obvious why cpufreq got limited.
People see cpufreq/scaling_max_freq reduced, but this could have
happened by:
  - any userspace prog writing to scaling_max_freq
  - thermal limitations
  - hardware (_PPC in ACPI case) limitiations

Therefore export bios_limit (in kHz) to:
  - Point the user that it's the BIOS (broken or intended) which limits
    frequency
  - Export it as a sysfs interface for userspace progs.
    While this was a rarely used feature on laptops, there will appear
    more and more server implemenations providing "Green IT" features like
    allowing the service processor to limit the frequency. People want
    to know about HW/BIOS frequency limitations.

All ACPI P-state driven cpufreq drivers are covered with this patch:
  - powernow-k8
  - powernow-k7
  - acpi-cpufreq

Tested with a patched DSDT which limits the first two cores (_PPC returns 1)
via _PPC, exposed by bios_limit:
# echo 2200000 >cpu2/cpufreq/scaling_max_freq
# cat cpu*/cpufreq/scaling_max_freq
2600000
2600000
2200000
2200000
# #scaling_max_freq shows general user/thermal/BIOS limitations

# cat cpu*/cpufreq/bios_limit
2600000
2600000
2800000
2800000
# #bios_limit only shows the HW/BIOS limitation

CC: Pallipadi Venkatesh <venkatesh.pallipadi@intel.com>
CC: Len Brown <lenb@kernel.org>
CC: davej@codemonkey.org.uk
CC: linux@dominikbrodowski.net

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
2009-11-24 13:33:34 -05:00
Alex Chiang
cf3289d0e7 [CPUFREQ] make internal cpufreq_add_dev_* static
No need to export these symbols; make them static.

	cpufreq_add_dev_policy
	cpufreq_add_dev_symlink
	cpufreq_add_dev_interface

Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2009-11-24 13:33:34 -05:00
Thomas Renninger
49b015ce38 [CPUFREQ] Use global sysfs cpufreq structure for conservative governor tunings
Same adustments that have been added to the ondemand recently.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
2009-11-24 13:33:34 -05:00
Prarit Bhargava
90e41bac10 [CPUFREQ] Fix stale cpufreq_cpu_governor pointer
Dave,

Attached is an update of my patch against the cpufreq fixes branch.

Before applying the patch I compiled and booted the tree to see if the panic
was still there -- to my surprise it was not.  This is because of the conversion
of cpufreq_cpu_governor to a char[].

While the panic is kaput, the problem of stale data continues and my patch is
still valid.  It is possible to end up with the wrong governor after hotplug
events because CPUFREQ_DEFAULT_GOVERNOR is statically linked to a default,
while the cpu siblings may have had a different governor assigned by a user.

ie) the patch is still needed in order to keep the governors assigned
properly when hotplugging devices

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2009-11-17 23:15:04 -05:00
Pallipadi, Venkatesh
54c9a35d9f [CPUFREQ] Resolve time unit thinko in ondemand/conservative govs
ondemand and conservative governors are messing up time units in the
code path where NO_HZ is not enabled and ignore_nice is set. The walltime
idletime stored is in jiffies and nice time calculation is happening in
microseconds.

The problem was reported and diagnosed by Alexander here.
http://marc.info/?l=linux-kernel&m=125752550404513&w=2

The patch below fixes this thinko.

Reported-by: Alexander Miller <Miller@fmi.uni-stuttgart.de>
Tested-by: Alexander Miller <Miller@fmi.uni-stuttgart.de>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2009-11-17 23:15:04 -05:00
Dmitry Monakhov
e77b89f13a [CPUFREQ] Fix use after free on governor restore
Currently on governer backup/restore path we storing governor's pointer.
This is wrong because one may unload governor's module after cpu goes
offline. As result use-after-free will take place on restored cpu.
It is not easy to exploit this bug, but still we have to close this
issue ASAP. Issue was introduced by following commit
084f349394

##TESTCASE##
#!/bin/sh -x
modprobe acpi_cpufreq
# Any non default governor, in may case it is "ondemand"
modprobe cpufreq_ondemand
echo ondemand > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
rmmod acpi_cpufreq
rmmod cpufreq_ondemand
modprobe acpi_cpufreq  # << use-after-free here.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Dave Jones <davej@redhat.com>
2009-11-17 23:15:04 -05:00
Tejun Heo
f16250669d percpu: make percpu symbols in cpufreq unique
This patch updates percpu related symbols in cpufreq such that percpu
symbols are unique and don't clash with local symbols.  This serves
two purposes of decreasing the possibility of global percpu symbol
collision and allowing dropping per_cpu__ prefix from percpu symbols.

* drivers/cpufreq/cpufreq.c: s/policy_cpu/cpufreq_policy_cpu/
* drivers/cpufreq/freq_table.c: s/show_table/cpufreq_show_table/
* arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c: s/drv_data/acfreq_data/
  					      s/old_perf/acfreq_old_perf/

Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
2009-10-29 22:34:13 +09:00
Linus Torvalds
714af06938 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
  [CPUFREQ] Fix NULL ptr regression in powernow-k8
  [CPUFREQ] Create a blacklist for processors that should not load the acpi-cpufreq module.
  [CPUFREQ] Powernow-k8: Enable more than 2 low P-states
  [CPUFREQ] remove rwsem lock from CPUFREQ_GOV_STOP call (second call site)
  [CPUFREQ] ondemand - Use global sysfs dir for tuning settings
  [CPUFREQ] Introduce global, not per core: /sys/devices/system/cpu/cpufreq
  [CPUFREQ] Bail out of cpufreq_add_dev if the link for a managed CPU got created
  [CPUFREQ] Factor out policy setting from cpufreq_add_dev
  [CPUFREQ] Factor out interface creation from cpufreq_add_dev
  [CPUFREQ] Factor out symlink creation from cpufreq_add_dev
  [CPUFREQ] cleanup up -ENOMEM handling in cpufreq_add_dev
  [CPUFREQ] Reduce scope of cpu_sys_dev in cpufreq_add_dev
  [CPUFREQ] update Doc for cpuinfo_cur_freq and scaling_cur_freq
2009-09-18 09:16:57 -07:00
Linus Torvalds
ada3fa1505 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (46 commits)
  powerpc64: convert to dynamic percpu allocator
  sparc64: use embedding percpu first chunk allocator
  percpu: kill lpage first chunk allocator
  x86,percpu: use embedding for 64bit NUMA and page for 32bit NUMA
  percpu: update embedding first chunk allocator to handle sparse units
  percpu: use group information to allocate vmap areas sparsely
  vmalloc: implement pcpu_get_vm_areas()
  vmalloc: separate out insert_vmalloc_vm()
  percpu: add chunk->base_addr
  percpu: add pcpu_unit_offsets[]
  percpu: introduce pcpu_alloc_info and pcpu_group_info
  percpu: move pcpu_lpage_build_unit_map() and pcpul_lpage_dump_cfg() upward
  percpu: add @align to pcpu_fc_alloc_fn_t
  percpu: make @dyn_size mandatory for pcpu_setup_first_chunk()
  percpu: drop @static_size from first chunk allocators
  percpu: generalize first chunk allocator selection
  percpu: build first chunk allocators selectively
  percpu: rename 4k first chunk allocator to page
  percpu: improve boot messages
  percpu: fix pcpu_reclaim() locking
  ...

Fix trivial conflict as by Tejun Heo in kernel/sched.c
2009-09-15 09:39:44 -07:00
Mathieu Desnoyers
395913d0b1 [CPUFREQ] remove rwsem lock from CPUFREQ_GOV_STOP call (second call site)
remove rwsem lock from CPUFREQ_GOV_STOP call (second call site)

commit	42a06f2166

Missed a call site for CPUFREQ_GOV_STOP to remove the rwlock taken around the
teardown. To make a long story short, the rwlock write-lock causes a circular
dependency with cancel_delayed_work_sync(), because the timer handler takes the
read lock.

Note that all callers to __cpufreq_set_policy are taking the rwsem. All sysfs
callers (writers) hold the write rwsem at the earliest sysfs calling stage.

However, the rwlock write-lock is not needed upon governor stop.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
CC: rjw@sisk.pl
CC: mingo@elte.hu
CC: Shaohua Li <shaohua.li@intel.com>
CC: Pekka Enberg <penberg@cs.helsinki.fi>
CC: Dave Young <hidave.darkstar@gmail.com>
CC: "Rafael J. Wysocki" <rjw@sisk.pl>
CC: Rusty Russell <rusty@rustcorp.com.au>
CC: trenn@suse.de
CC: sven.wegener@stealer.net
CC: cpufreq@vger.kernel.org
Signed-off-by: Dave Jones <davej@redhat.com>
2009-09-01 12:45:18 -04:00
Thomas Renninger
0e625ac153 [CPUFREQ] ondemand - Use global sysfs dir for tuning settings
Ondemand has only global variables for userspace tunings via sysfs.
But they were exposed per CPU which wrongly implies to the user that
his settings are applied per cpu. Also locking sysfs against concurrent
access won't be necessary anymore after deprecation time.

This means the ondemand config dir is moved:
/sys/devices/system/cpu/cpu*/cpufreq/ondemand ->
     /sys/devices/system/cpu/cpufreq/ondemand

The old files will still exist, but reading or writing to them will
result in one (printk_once) deprecation msg to syslog per file.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
2009-09-01 12:45:18 -04:00
Thomas Renninger
8aa84ad8d6 [CPUFREQ] Introduce global, not per core: /sys/devices/system/cpu/cpufreq
Currently everything in the cpufreq layer is per core based.
This does not reflect reality, for example ondemand on conservative
governors have global sysfs variables.

Introduce a global cpufreq directory and add the kobject to the governor
struct, so that governors can easily access it.
The directory is initialized in the cpufreq_core_init initcall and thus will
always be created if cpufreq is compiled in, even if no cpufreq driver is
active later.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
2009-09-01 12:45:14 -04:00
Thomas Renninger
4bfa042cd3 [CPUFREQ] Bail out of cpufreq_add_dev if the link for a managed CPU got created
Doing:
echo 0 >cpu1/online
echo 1 >cpu1/online

on a managed CPU will result in:
Jul 22 15:15:37 linux kernel: [   80.013864] WARNING: at fs/sysfs/dir.c:487 sysfs_add_one+0xcf/0xe6()
Jul 22 15:15:37 linux kernel: [   80.013866] Hardware name: To Be Filled By O.E.M.
Jul 22 15:15:37 linux kernel: [   80.013868] sysfs: cannot create duplicate filename '/devices/system/cpu/cpu1/cpufreq'
Jul 22 15:15:37 linux kernel: [   80.013870] Modules linked in: powernow_k8
Jul 22 15:15:37 linux kernel: [   80.013874] Pid: 5750, comm: bash Not tainted 2.6.31-rc2 #40
Jul 22 15:15:37 linux kernel: [   80.013876] Call Trace:
Jul 22 15:15:37 linux kernel: [   80.013879]  [<ffffffff8112ebda>] ? sysfs_add_one+0xcf/0xe6
Jul 22 15:15:37 linux kernel: [   80.013884]  [<ffffffff81041926>] warn_slowpath_common+0x77/0xa4
Jul 22 15:15:37 linux kernel: [   80.013888]  [<ffffffff810419a0>] warn_slowpath_fmt+0x3c/0x3e
Jul 22 15:15:37 linux kernel: [   80.013891]  [<ffffffff8112ebda>] sysfs_add_one+0xcf/0xe6
Jul 22 15:15:37 linux kernel: [   80.013894]  [<ffffffff8112f213>] create_dir+0x58/0x87
Jul 22 15:15:37 linux kernel: [   80.013898]  [<ffffffff8112f27a>] sysfs_create_dir+0x38/0x4f
Jul 22 15:15:37 linux kernel: [   80.013902]  [<ffffffff811ffb8a>] kobject_add_internal+0x11f/0x1de
Jul 22 15:15:37 linux kernel: [   80.013905]  [<ffffffff811ffd21>] kobject_add_varg+0x41/0x4e
Jul 22 15:15:37 linux kernel: [   80.013908]  [<ffffffff811ffd7a>] kobject_init_and_add+0x4c/0x57
Jul 22 15:15:37 linux kernel: [   80.013913]  [<ffffffff810667bc>] ? mark_lock+0x22/0x228
Jul 22 15:15:37 linux kernel: [   80.013918]  [<ffffffff813e8a3b>] cpufreq_add_dev_interface+0x40/0x1e4
...

This bug slipped in by git commit:
150b06f7f223cfd0f808737a5243cceca8ea47fa

When splitting up cpufreq_add_dev, the whole cpufreq_add_dev function
is not left anymore, only cpufreq_add_dev_policy.
This patch should reconstruct the identical functionality again as it
was before the split.

CC: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
2009-09-01 12:45:14 -04:00
Dave Jones
ecf7e4611c [CPUFREQ] Factor out policy setting from cpufreq_add_dev
Signed-off-by: Dave Jones <davej@redhat.com>
2009-09-01 12:45:14 -04:00
Dave Jones
909a694e33 [CPUFREQ] Factor out interface creation from cpufreq_add_dev
Signed-off-by: Dave Jones <davej@redhat.com>
2009-09-01 12:45:13 -04:00
Dave Jones
19d6f7ec3e [CPUFREQ] Factor out symlink creation from cpufreq_add_dev
Signed-off-by: Dave Jones <davej@redhat.com>
2009-09-01 12:45:12 -04:00
Dave Jones
059019a3c3 [CPUFREQ] cleanup up -ENOMEM handling in cpufreq_add_dev
Signed-off-by: Dave Jones <davej@redhat.com>
2009-09-01 12:45:09 -04:00