summaryrefslogtreecommitdiff
path: root/drivers/cpufreq/cpufreq.c
AgeCommit message (Collapse)Author
2009-11-18[CPUFREQ] Fix stale cpufreq_cpu_governor pointerPrarit Bhargava
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>
2009-11-18[CPUFREQ] Fix use after free on governor restoreDmitry Monakhov
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 084f34939424161669467c19280dbcf637730314 ##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>
2009-09-01[CPUFREQ] remove rwsem lock from CPUFREQ_GOV_STOP call (second call site)Mathieu Desnoyers
remove rwsem lock from CPUFREQ_GOV_STOP call (second call site) commit 42a06f2166f2f6f7bf04f32b4e823eacdceafdc9 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[CPUFREQ] Introduce global, not per core: /sys/devices/system/cpu/cpufreqThomas Renninger
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[CPUFREQ] Bail out of cpufreq_add_dev if the link for a managed CPU got createdThomas Renninger
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[CPUFREQ] Factor out policy setting from cpufreq_add_devDave Jones
Signed-off-by: Dave Jones <davej@redhat.com>
2009-09-01[CPUFREQ] Factor out interface creation from cpufreq_add_devDave Jones
Signed-off-by: Dave Jones <davej@redhat.com>
2009-09-01[CPUFREQ] Factor out symlink creation from cpufreq_add_devDave Jones
Signed-off-by: Dave Jones <davej@redhat.com>
2009-09-01[CPUFREQ] cleanup up -ENOMEM handling in cpufreq_add_devDave Jones
Signed-off-by: Dave Jones <davej@redhat.com>
2009-09-01[CPUFREQ] Reduce scope of cpu_sys_dev in cpufreq_add_devDave Jones
Signed-off-by: Dave Jones <davej@redhat.com>
2009-09-01[CPUFREQ] Re-enable cpufreq suspend and resume codeDominik Brodowski
Commit 4bc5d3413503 is broken and causes regressions: (1) cpufreq_driver->resume() and ->suspend() were only called on __powerpc__, but you could set them on all architectures. In fact, ->resume() was defined and used before the PPC-related commit 42d4dc3f4e1e complained about in 4bc5d3413503. (2) Therfore, the resume functions in acpi_cpufreq and speedstep-smi would never be called. (3) This means speedstep-smi would be unusuable after suspend or resume. The _real_ problem was calling cpufreq_driver->get() with interrupts off, but it re-enabling interrupts on some platforms. Why is ->get() necessary? Some systems like to change the CPU frequency behind our back, especially during BIOS-intensive operations like suspend or resume. If such systems also use a CPU frequency-dependant timing loop, delays might be off by large factors. Therefore, we need to ascertain as soon as possible that the CPU frequency is indeed at the speed we think it is. You can do this two ways: either setting it anew, or trying to get it. The latter is what was done, the former also has the same IRQ issue. So, let's try something different: defer the checking to after interrupts are re-enabled, by calling cpufreq_update_policy() (via schedule_work()). Timings may be off until this later stage, so let's watch out for resume regressions caused by the deferred handling of frequency changes behind the kernel's back. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Dave Jones <davej@redhat.com>
2009-08-04[CPUFREQ] Make cpufreq suspend code conditional on powerpc.Dave Jones
The suspend code runs with interrupts disabled, and the powerpc workaround we do in the cpufreq suspend hook calls the drivers ->get method. powernow-k8's ->get does an smp_call_function_single which needs interrupts enabled cpufreq's suspend/resume code was added in 42d4dc3f4e1e to work around a hardware problem on ppc powerbooks. If we make all this code conditional on powerpc, we avoid the issue above. Signed-off-by: Dave Jones <davej@redhat.com>
2009-08-04[CPUFREQ] Fix a kobject reference bug related to managed CPUsThomas Renninger
The first offline/online cycle is successful, the second not. Doing: echo 0 >cpu1/online echo 1 >cpu1/online echo 0 >cpu1/online The last command will trigger: Jul 22 14:39:50 linux kernel: [ 593.210125] ------------[ cut here ]------------ Jul 22 14:39:50 linux kernel: [ 593.210139] WARNING: at lib/kref.c:43 kref_get+0x23/0x2b() Jul 22 14:39:50 linux kernel: [ 593.210144] Hardware name: To Be Filled By O.E.M. Jul 22 14:39:50 linux kernel: [ 593.210148] Modules linked in: powernow_k8 Jul 22 14:39:50 linux kernel: [ 593.210158] Pid: 378, comm: kondemand/2 Tainted: G W 2.6.31-rc2 #38 Jul 22 14:39:50 linux kernel: [ 593.210163] Call Trace: Jul 22 14:39:50 linux kernel: [ 593.210171] [<ffffffff812008e8>] ? kref_get+0x23/0x2b Jul 22 14:39:50 linux kernel: [ 593.210181] [<ffffffff81041926>] warn_slowpath_common+0x77/0xa4 Jul 22 14:39:50 linux kernel: [ 593.210190] [<ffffffff81041962>] warn_slowpath_null+0xf/0x11 Jul 22 14:39:50 linux kernel: [ 593.210198] [<ffffffff812008e8>] kref_get+0x23/0x2b Jul 22 14:39:50 linux kernel: [ 593.210206] [<ffffffff811ffa19>] kobject_get+0x1a/0x22 Jul 22 14:39:50 linux kernel: [ 593.210214] [<ffffffff813e815d>] cpufreq_cpu_get+0x8a/0xcb Jul 22 14:39:50 linux kernel: [ 593.210222] [<ffffffff813e87d1>] __cpufreq_driver_getavg+0x1d/0x67 Jul 22 14:39:50 linux kernel: [ 593.210231] [<ffffffff813ea18f>] do_dbs_timer+0x158/0x27f Jul 22 14:39:50 linux kernel: [ 593.210240] [<ffffffff810529ea>] worker_thread+0x200/0x313 ... The output continues on every do_dbs_timer ondemand freq checking poll. This regression was introduced by git commit: 3f4a782b5ce2698b1870b5a7b573cd721d4fce33 The policy is released when the cpufreq device is removed in: __cpufreq_remove_dev(): /* if this isn't the CPU which is the parent of the kobj, we * only need to unlink, put and exit */ Not creating the symlink is not sever at all. As long as: sysfs_remove_link(&sys_dev->kobj, "cpufreq"); handles it gracefully that the symlink did not exist. Possibly no error should be returned at all, because ondemand governor would still provide the same functionality. Userspace in userspace gov case might be confused if the link is missing. Resolves http://bugzilla.kernel.org/show_bug.cgi?id=13903 CC: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> CC: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com>
2009-08-04[CPUFREQ] Do not set policy for offline cpusPrarit Bhargava
Suspend/Resume fails on multi socket, multi core systems because the cpufreq code erroneously sets the per_cpu policy_cpu value when a logical cpu is offline. This most notably results in missing sysfs files that are used to set the cpu frequencies of the various cpus. Signed-off-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Dave Jones <davej@redhat.com>
2009-07-08[CPUFREQ] Fix compile failure in cpufreq.cDave Jones
managed_policy is out of scope for the non-smp case. Declare it locally where used (twice) Signed-off-by: Dave Jones <davej@redhat.com>
2009-07-07[CPUFREQ] fix (utter) cpufreq_add_dev messMathieu Desnoyers
OK, I've tried to clean it up the best I could, but please test this with concurrent cpu hotplug and cpufreq add/remove in loops. I'm sure we will make other interesting findings. This is step one of fixing the overall locking dependency mess in cpufreq. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> CC: 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: sven.wegener@stealer.net CC: cpufreq@vger.kernel.org CC: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com>
2009-07-07[CPUFREQ] Eliminate the recent lockdep warnings in cpufreqvenkatesh.pallipadi@intel.com
Commit b14893a62c73af0eca414cfed505b8c09efc613c although it was very much needed to properly cleanup ondemand timer, opened-up a can of worms related to locking dependencies in cpufreq. Patch here defines the need for dbs_mutex and cleans up its usage in ondemand governor. This also resolves the lockdep warnings reported here http://lkml.indiana.edu/hypermail/linux/kernel/0906.1/01925.html http://lkml.indiana.edu/hypermail/linux/kernel/0907.0/00820.html and few others.. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
2009-06-09cpumask: alloc zeroed cpumask for static cpumask_var_tsYinghai Lu
These are defined as static cpumask_var_t so if MAXSMP is not used, they are cleared already. Avoid surprises when MAXSMP is enabled. Signed-off-by: Yinghai Lu <yinghai.lu@kernel.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-05-26[CPUFREQ] remove rwsem lock from CPUFREQ_GOV_STOP callMathieu Desnoyers
* Rafael J. Wysocki (rjw@sisk.pl) wrote: > This message has been generated automatically as a part of a report > of regressions introduced between 2.6.28 and 2.6.29. > > The following bug entry is on the current list of known regressions > introduced between 2.6.28 and 2.6.29. Please verify if it still should > be listed and let me know (either way). > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=13186 > Subject : cpufreq timer teardown problem > Submitter : Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> > Date : 2009-04-23 14:00 (24 days old) > References : http://marc.info/?l=linux-kernel&m=124049523515036&w=4 > Handled-By : Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> > Patch : http://patchwork.kernel.org/patch/19754/ > http://patchwork.kernel.org/patch/19753/ The patches linked above depend on the following patch to remove circular locking dependency : cpufreq: remove rwsem lock from CPUFREQ_GOV_STOP call (the following issue was faced when using cancel_delayed_work_sync() in the timer teardown (which fixes a race). * KOSAKI Motohiro (kosaki.motohiro@jp.fujitsu.com) wrote: > Hi > > my box output following warnings. > it seems regression by commit 7ccc7608b836e58fbacf65ee4f8eefa288e86fac. > > A: work -> do_dbs_timer() -> cpu_policy_rwsem > B: store() -> cpu_policy_rwsem -> cpufreq_governor_dbs() -> work > > Hrm, I think it must be due to my attempt to fix the timer teardown race in ondemand governor mixed with new locking behavior in 2.6.30-rc. The rwlock seems to be taken around the whole call to cpufreq_governor_dbs(), when it should be only taken around accesses to the locked data, and especially *not* around the call to dbs_timer_exit(). Reverting my fix attempt would put the teardown race back in place (replacing the cancel_delayed_work_sync by cancel_delayed_work). Instead, a proper fix would imply modifying this critical section : cpufreq.c: __cpufreq_remove_dev() ... if (cpufreq_driver->target) __cpufreq_governor(data, CPUFREQ_GOV_STOP); unlock_policy_rwsem_write(cpu); To make sure the __cpufreq_governor() callback is not called with rwsem held. This would allow execution of cancel_delayed_work_sync() without being nested within the rwsem. Applies on top of the 2.6.30-rc5 tree. Required to remove circular dep in teardown of both conservative and ondemande governors so they can use cancel_delayed_work_sync(). CPUFREQ_GOV_STOP does not modify the policy, therefore this locking seemed unneeded. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Greg KH <greg@kroah.com> CC: Ingo Molnar <mingo@elte.hu> CC: "Rafael J. Wysocki" <rjw@sisk.pl> CC: Ben Slusky <sluskyb@paranoiacs.org> CC: Chris Wright <chrisw@sous-sol.org> CC: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Jones <davej@redhat.com>
2009-03-26Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq: (35 commits) [CPUFREQ] Prevent p4-clockmod from auto-binding to the ondemand governor. [CPUFREQ] Make cpufreq-nforce2 less obnoxious [CPUFREQ] p4-clockmod reports wrong frequency. [CPUFREQ] powernow-k8: Use a common exit path. [CPUFREQ] Change link order of x86 cpufreq modules [CPUFREQ] conservative: remove 10x from def_sampling_rate [CPUFREQ] conservative: fixup governor to function more like ondemand logic [CPUFREQ] conservative: fix dbs_cpufreq_notifier so freq is not locked [CPUFREQ] conservative: amend author's email address [CPUFREQ] Use swap() in longhaul.c [CPUFREQ] checkpatch cleanups for acpi-cpufreq [CPUFREQ] powernow-k8: Only print error message once, not per core. [CPUFREQ] ondemand/conservative: sanitize sampling_rate restrictions [CPUFREQ] ondemand/conservative: deprecate sampling_rate{min,max} [CPUFREQ] powernow-k8: Always compile powernow-k8 driver with ACPI support [CPUFREQ] Introduce /sys/devices/system/cpu/cpu*/cpufreq/cpuinfo_transition_latency [CPUFREQ] checkpatch cleanups for powernow-k8 [CPUFREQ] checkpatch cleanups for ondemand governor. [CPUFREQ] checkpatch cleanups for powernow-k7 [CPUFREQ] checkpatch cleanups for speedstep related drivers. ...
2009-03-09Revert "[CPUFREQ] Disable sysfs ui for p4-clockmod."Dave Jones
This reverts commit e088e4c9cdb618675874becb91b2fd581ee707e6. Removing the sysfs interface for p4-clockmod was flagged as a regression in bug 12826. Course of action: - Find out the remaining causes of overheating, and fix them if possible. ACPI should be doing the right thing automatically. If it isn't, we need to fix that. - mark p4-clockmod ui as deprecated - try again with the removal in six months. It's not really feasible to printk about the deprecation, because it needs to happen at all the sysfs entry points, which means adding a lot of strcmp("p4-clockmod".. calls to the core, which.. bleuch. Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-25[CPUFREQ] Introduce ↵Thomas Renninger
/sys/devices/system/cpu/cpu*/cpufreq/cpuinfo_transition_latency It's not only useful for the ondemand and conservative governors, but also for userspace daemons to know about the HW transition latency of the CPU. It is especially useful for userspace to know about this value when the ondemand or conservative governors are run. The sampling rate control value depends on it and for userspace being able to set sane tuning values there it has to know about the transition latency. Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-25[CPUFREQ] checkpatch cleanups for cpufreq coreDave Jones
Signed-off-by: Dave Jones <davej@redhat.com>
2009-01-06cpumask: convert struct cpufreq_policy to cpumask_var_tRusty Russell
Impact: use new cpumask API to reduce memory usage This is part of an effort to reduce structure sizes for machines configured with large NR_CPUS. cpumask_t gets replaced by cpumask_var_t, which is either struct cpumask[1] (small NR_CPUS) or struct cpumask * (large NR_CPUS). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Mike Travis <travis@sgi.com> Acked-by: Dave Jones <davej@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-05[CPUFREQ] Fix on resume, now preserves user policy min/max.Mike Chan
Previously driver resume would always set the current policy min/max with the cpuinfo min/max, defined by user_policy.min/max. Resulting in a reset of policy settings when policy.min/max != cpuinfo.min/max when coming out of suspend. Now user_policy is saved as the policy instead of cpuinfo to preserve what the user actually set. Signed-off-by: Mike Chan <mike@android.com> Signed-off-by: Dave Jones <davej@redhat.com>
2008-12-05[CPUFREQ] Disable sysfs ui for p4-clockmod.Matthew Garrett
p4-clockmod has a long history of abuse. It pretends to be a CPU frequency scaling driver, even though it doesn't actually change the CPU frequency, but instead just modulates the frequency with wait-states. The biggest misconception is that when running at the lower 'frequency' p4-clockmod is saving power. This isn't the case, as workloads running slower take longer to complete, preventing the CPU from entering deep C states. However p4-clockmod does have a purpose. It can prevent overheating. Having it hooked up to the cpufreq interfaces is the wrong way to achieve cooling however. It should instead be hooked up to ACPI. This diff introduces a means for a cpufreq driver to register with the cpufreq core, but not present a sysfs interface. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Dave Jones <davej@redhat.com>
2008-10-09[CPUFREQ][1/6] cpufreq: Add cpu number parameter to __cpufreq_driver_getavg()venkatesh.pallipadi@intel.com
Add a cpu parameter to __cpufreq_driver_getavg(). This is needed for software cpufreq coordination where policy->cpu may not be same as the CPU on which we want to getavg frequency. A follow-on patch will use this parameter to getavg freq from all cpus in policy->cpus. Change since last patch. Fix the offline/online and suspend/resume oops reported by Youquan Song <youquan.song@intel.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
2008-10-09[CPUFREQ] drivers/cpufreq/cpufreq.c: Adjust error handling code involving ↵Julia Lawall
cpufreq_cpu_put After calling cpufreq_cpu_get, error handling code should call cpufreq_cpu_put. The semantic match that finds this problem is as follows: (http://www.emn.fr/x-info/coccinelle/) // <smpl> @r@ expression x,E; statement S; position p1,p2,p3; @@ ( if ((x = cpufreq_cpu_get@p1(...)) == NULL || ...) S | x = cpufreq_cpu_get@p1(...) ... when != x if (x == NULL || ...) S ) <... if@p3 (...) { ... when != cpufreq_cpu_put(x) when != if (x) { ... cpufreq_cpu_put(x); ...} return@p2 ...; } ...> ( return x; | return 0; | x = E | E = x | cpufreq_cpu_put(x) ) @exists@ position r.p1,r.p2,r.p3; expression x; int ret != 0; statement S; @@ * x = cpufreq_cpu_get@p1(...) <... * if@p3 (...) S ...> * return@p2 \(NULL\|ret\); // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Dave Jones <davej@redhat.com>
2008-07-30cpufreq acpi: only call _PPC after cpufreq ACPI init funcs got called alreadyThomas Renninger
Ingo Molnar provided a fix to not call _PPC at processor driver initialization time in "[PATCH] ACPI: fix cpufreq regression" (git commit e4233dec749a3519069d9390561b5636a75c7579) But it can still happen that _PPC is called at processor driver initialization time. This patch should make sure that this is not possible anymore. Signed-off-by: Thomas Renninger <trenn@suse.de> Cc: Andi Kleen <andi@firstfloor.org> Cc: Len Brown <lenb@kernel.org> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Ingo Molnar <mingo@elte.hu> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24Merge branch 'cpus4096-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'cpus4096-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (31 commits) NR_CPUS: Replace NR_CPUS in speedstep-centrino.c cpumask: Provide a generic set of CPUMASK_ALLOC macros, FIXUP NR_CPUS: Replace NR_CPUS in cpufreq userspace routines NR_CPUS: Replace per_cpu(..., smp_processor_id()) with __get_cpu_var NR_CPUS: Replace NR_CPUS in arch/x86/kernel/genapic_flat_64.c NR_CPUS: Replace NR_CPUS in arch/x86/kernel/genx2apic_uv_x.c NR_CPUS: Replace NR_CPUS in arch/x86/kernel/cpu/proc.c NR_CPUS: Replace NR_CPUS in arch/x86/kernel/cpu/mcheck/mce_64.c cpumask: Optimize cpumask_of_cpu in lib/smp_processor_id.c, fix cpumask: Use optimized CPUMASK_ALLOC macros in the centrino_target cpumask: Provide a generic set of CPUMASK_ALLOC macros cpumask: Optimize cpumask_of_cpu in lib/smp_processor_id.c cpumask: Optimize cpumask_of_cpu in kernel/time/tick-common.c cpumask: Optimize cpumask_of_cpu in drivers/misc/sgi-xp/xpc_main.c cpumask: Optimize cpumask_of_cpu in arch/x86/kernel/ldt.c cpumask: Optimize cpumask_of_cpu in arch/x86/kernel/io_apic_64.c cpumask: Replace cpumask_of_cpu with cpumask_of_cpu_ptr Revert "cpumask: introduce new APIs" cpumask: make for_each_cpu_mask a bit smaller net: Pass reference to cpumask variable in net/sunrpc/svc.c ... Fix up trivial conflicts in drivers/cpufreq/cpufreq.c manually
2008-07-21Merge branch 'next' of ↵Linus Torvalds
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] cpufreq: remove CVS keywords [CPUFREQ] change cpu freq arrays to per_cpu variables
2008-07-06Merge commit 'v2.6.26-rc9' into cpus4096Ingo Molnar
2008-06-09Merge branch 'fixes' of ↵Linus Torvalds
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] Fix format string bug.
2008-06-09[CPUFREQ] Fix format string bug.Chris Wright
Format string bug. Not exploitable, as this is only writable by root, but worth fixing all the same. Spotted-by: Ilja van Sprundel <ilja@netric.org> Signed-off-by: Dave Jones <davej@redhat.com>
2008-06-06cpufreq: fix null object access on Transmeta CPUCHIKAMA masaki
If cpu specific cpufreq driver(i.e. longrun) has "setpolicy" function, governor object isn't set into cpufreq_policy object at "__cpufreq_set_policy" function in driver/cpufreq/cpufreq.c . This causes a null object access at "store_scaling_setspeed" and "show_scaling_setspeed" function in driver/cpufreq/cpufreq.c when reading or writing through /sys interface (ex. cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed) Addresses: http://bugzilla.kernel.org/show_bug.cgi?id=10654 https://bugzilla.redhat.com/show_bug.cgi?id=443354 Signed-off-by: CHIKAMA Masaki <masaki.chikama@gmail.com> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Chuck Ebbert <cebbert@redhat.com> Acked-by: Dominik Brodowski <linux@dominikbrodowski.net> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-29[CPUFREQ] fix double unlock of cpu_policy_rwsem in drivers/cpufreq/cpufreq.cLothar Waßmann
In drivers/cpufreq/cpufreq.c the function cpufreq_add_dev() takes the error exit 'err_out_unregister' from different places once with the 'cpu_policy_rwsem' lock held, once with the lock released: | if (ret) | goto err_out_unregister; | } | | policy->governor = NULL; /* to assure that the starting sequence is | * run in cpufreq_set_policy */ | | /* set default policy */ | ret = __cpufreq_set_policy(policy, &new_policy); | policy->user_policy.policy = policy->policy; | policy->user_policy.governor = policy->governor; | | unlock_policy_rwsem_write(cpu); | | if (ret) { | dprintk("setting policy failed\n"); | goto err_out_unregister; | } This leads to the following error message in case of a failing __cpufreq_set_policy() call: ===================================== [ BUG: bad unlock balance detected! ] ------------------------------------- swapper/1 is trying to release lock (&per_cpu(cpu_policy_rwsem, cpu)) at: [<c01b4564>] unlock_policy_rwsem_write+0x30/0x40 but there are no more locks to release! other info that might help us debug this: 1 lock held by swapper/1: #0: (sysdev_drivers_lock){--..}, at: [<c018fd18>] sysdev_driver_register+0x74/0x130 stack backtrace: [<c002f588>] (dump_stack+0x0/0x14) from [<c00692fc>] (print_unlock_inbalance_bug+0xc8/0x104) [<c0069234>] (print_unlock_inbalance_bug+0x0/0x104) from [<c006b7ac>] (lock_release_non_nested+0xc4/0x19c) r6:00000028 r5:c3c1ab80 r4:c01b4564 [<c006b6e8>] (lock_release_non_nested+0x0/0x19c) from [<c006b9e0>] (lock_release+0x15c/0x18c) r8:60000013 r7:00000001 r6:c01b4564 r5:c0541bb4 r4:c3c1ab80 [<c006b884>] (lock_release+0x0/0x18c) from [<c0061ba0>] (up_write+0x24/0x30) r8:c0541b80 r7:00000000 r6:ffffffea r5:c3c34828 r4:c0541b8c [<c0061b7c>] (up_write+0x0/0x30) from [<c01b4564>] (unlock_policy_rwsem_write+0x30/0x40) r4:c3c34884 [<c01b4534>] (unlock_policy_rwsem_write+0x0/0x40) from [<c01b4c40>] (cpufreq_add_dev+0x324/0x398) [<c01b491c>] (cpufreq_add_dev+0x0/0x398) from [<c018fd64>] (sysdev_driver_register+0xc0/0x130) [<c018fca4>] (sysdev_driver_register+0x0/0x130) from [<c01b3574>] (cpufreq_register_driver+0xbc/0x174) Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de> Signed-off-by: Dave Jones <davej@redhat.com>
2008-05-23cpufreq: use performance variant for_each_cpu_mask_nrMike Travis
Change references from for_each_cpu_mask to for_each_cpu_mask_nr where appropriate Reviewed-by: Paul Jackson <pj@sgi.com> Reviewed-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-19[CPUFREQ] change cpu freq arrays to per_cpu variablesMike Travis
Change cpufreq_policy and cpufreq_governor pointer tables from arrays to per_cpu variables in the cpufreq subsystem. Also some minor complaints from checkpatch.pl fixed. Based on: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86.git Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Dave Jones <davej@redhat.com>
2008-04-28[CPUFREQ] expose cpufreq coordination requirements regardless of ↵Darrick J. Wong
coordination mechanism Currently, affected_cpus shows which CPUs need to have their frequency coordinated in software. When hardware coordination is in use, the contents of this file appear the same as when no coordination is required. This can lead to some confusion among user-space programs, for example, that do not know that extra coordination is required to force a CPU core to a particular speed to control power consumption. To fix this, create a "related_cpus" attribute that always displays the coordination map regardless of whatever coordination strategy the cpufreq driver uses (sw or hw). If the cpufreq driver does not provide a value, fall back to policy->cpus. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Jones <davej@redhat.com>
2008-04-28[CPUFREQ] Warn when cpufreq_register_notifier called before pure initcallsCesar Eduardo Barros
If cpufreq_register_notifier is called before pure initcalls, init_cpufreq_transition_notifier_list will overwrite whatever it did, causing notifiers to be ignored. Print some noise to the kernel log if that happens. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Signed-off-by: Dave Jones <davej@codemonkey.org.uk>
2008-04-28[CPUFREQ] Refactor locking in cpufreq_add_devDave Jones
Simplify this by moving the unlocking out of the error paths into the exit path. Signed-off-by: Dave Jones <davej@codemonkey.org.uk>
2008-04-28[CPUFREQ] more CodingStyleDave Jones
void * p -> void *p no space between function parameters removed excess whitespace Signed-off-by: Dave Jones <davej@codemonkey.org.uk>
2008-04-28[CPUFREQ] CodingStyleDave Jones
return is not a function. Signed-off-by: Dave Jones <davej@redhat.com>
2008-04-28[CPUFREQ] Slightly shorten the error paths of cpufreq_suspend/cpufreq_resumeDave Jones
Signed-off-by: Dave Jones <davej@redhat.com>
2008-03-05[CPUFREQ] fix section mismatch warningsSam Ravnborg
Fix the following warnings: WARNING: vmlinux.o(.text+0xfe6711): Section mismatch in reference from the function cpufreq_unregister_driver() to the variable .cpuinit.data:cpufreq_cpu_notifier WARNING: vmlinux.o(.text+0xfe68af): Section mismatch in reference from the function cpufreq_register_driver() to the variable .cpuinit.data:cpufreq_cpu_notifier WARNING: vmlinux.o(.exit.text+0xc4fa): Section mismatch in reference from the function cpufreq_stats_exit() to the variable .cpuinit.data:cpufreq_stat_cpu_notifier The warnings were casued by references to unregister_hotcpu_notifier() from normal functions or exit functions. This is flagged by modpost as a potential error because it does not know that for the non HOTPLUG_CPU scenario the unregister_hotcpu_notifier() is a nop. Silence the warning by replacing the __initdata annotation with a __refdata annotation. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Dave Jones <davej@codemonkey.org.uk>
2008-03-05[CPUFREQ] Fix missing cpufreq_cpu_put() call in ->storeDave Jones
refactor to use gotos instead of explicit exit paths Signed-off-by: Dave Jones <davej@redhat.com>
2008-03-05[CPUFREQ] Fix missing cpufreq_cpu_put() call in ->showDave Jones
refactor to use gotos instead of explicit exit paths Signed-off-by: Dave Jones <davej@redhat.com>
2008-02-21cpufreq: fix kobject reference count handlingBalaji Rao
The cpufreq core should not take an extra kobject reference count for no reason, and then refuse to release it. This has been reported as keeping machines from properly powering down all the way. Signed-off-by: Balaji Rao <balajirrao@gmail.com> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Yi Yang <yi.y.yang@intel.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Frans Pop <elendil@planet.nl> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-07[CPUFREQ] Eliminate cpufreq_userspace scaling_setspeed deadlockVenki Pallipadi
Eliminate cpufreq_userspace scaling_setspeed deadlock. Luming Yu recently uncovered yet another cpufreq related deadlock. One thread that continuously switches the governors and the other thread that repeatedly cats the contents of cpufreq directory causes both these threads to go into a deadlock. Detailed examination of the deadlock showed the exact flow before the deadlock as: Thread 1 Thread 2 ________ ________ cats files under /sys/devices/.../cpufreq/ Set governor to userspace Adds a new sysfs entry for scaling_setspeed cats files under /sys/devices/.../cpufreq/ Set governor to performance Holds cpufreq_rw_sem in write mode Sends a STOP notify to userspace governor cat /sys/devices/.../cpufreq/scaling_setspeed Gets a handle on the above sysfs entry with sysfs_get_active Blocks while trying to get cpufreq_rw_sem in read mode Remove a sysfs entry for scaling_setspeed Blocks on sysfs_deactivate while waiting for earlier get_active (on other thread) to drain At this point both threads go into deadlock and any other thread that tries to do anything with sysfs cpufreq will also block. There seems to be no easy way to avoid this deadlock as long as cpufreq_userspace adds/removes the sysfs entry under same kobject as cpufreq. Below patch moves scaling_setspeed to cpufreq.c, keeping it always and calling back the governor on read/write. This is the cleanest fix I could think of, even though adding two callbacks in governor structure just for this seems unnecessary. Note that the change makes scaling_setspeed under /sys/.../cpufreq permanent and returns <unsupported> when governor is not userspace. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
2008-02-07[CPUFREQ] drivers/cpufreq: Add missing "space"Joe Perches
Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Dave Jones <davej@redhat.com>