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2009-09-18Merge 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] 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
2009-09-15Merge branch 'for-linus' of ↵Linus Torvalds
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
2009-09-01[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] ondemand - Use global sysfs dir for tuning settingsThomas Renninger
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[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>
2009-08-14Merge branch 'percpu-for-linus' into percpu-for-nextTejun Heo
Conflicts: arch/sparc/kernel/smp_64.c arch/x86/kernel/cpu/perf_counter.c arch/x86/kernel/setup_percpu.c drivers/cpufreq/cpufreq_ondemand.c mm/percpu.c Conflicts in core and arch percpu codes are mostly from commit ed78e1e078dd44249f88b1dd8c76dafb39567161 which substituted many num_possible_cpus() with nr_cpu_ids. As for-next branch has moved all the first chunk allocators into mm/percpu.c, the changes are moved from arch code to mm/percpu.c. Signed-off-by: Tejun Heo <tj@kernel.org>
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>
2009-08-04[CPUFREQ] Fix NULL pointer dereference regression in conservative governorPallipadi, Venkatesh
Commit ee88415caf736b89500f16e0a545614541a45005 introduced this regression when it removed enable bit in cpu_dbs_info_s. That added a possibility of dbs_cpufreq_notifier getting called for a CPU that is not yet managed by conservative governor. That will happen as the transition notifier is set as soon as one CPU switches to conservative governor and other CPUs can get a NULL pointer dereference without the enable bit check. Add the enable bit back again. Reported-by: Lermytte Christophe <Christophe.Lermytte@thomson.net> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.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>
2009-07-06[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>
2009-07-06[CPUFREQ] Cleanup locking in conservative governorvenkatesh.pallipadi@intel.com
Redesign the locking inside conservative driver. Make dbs_mutex handle all the global state changes inside the driver and invent a new percpu mutex to serialize percpu timer and frequency limit change. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
2009-07-06[CPUFREQ] Cleanup locking in ondemand governorvenkatesh.pallipadi@intel.com
Redesign the locking inside ondemand driver. Make dbs_mutex handle all the global state changes inside the driver and invent a new percpu mutex to serialize percpu timer and frequency limit change. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
2009-07-06[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>
2009-06-24percpu: clean up percpu variable definitionsTejun Heo
Percpu variable definition is about to be updated such that all percpu symbols including the static ones must be unique. Update percpu variable definitions accordingly. * as,cfq: rename ioc_count uniquely * cpufreq: rename cpu_dbs_info uniquely * xen: move nesting_count out of xen_evtchn_do_upcall() and rename it * mm: move ratelimits out of balance_dirty_pages_ratelimited_nr() and rename it * ipv4,6: rename cookie_scratch uniquely * x86 perf_counter: rename prev_left to pmc_prev_left, irq_entry to pmc_irq_entry and nmi_entry to pmc_nmi_entry * perf_counter: rename disable_count to perf_disable_count * ftrace: rename test_event_disable to ftrace_test_event_disable * kmemleak: rename test_pointer to kmemleak_test_pointer * mce: rename next_interval to mce_next_interval [ Impact: percpu usage cleanups, no duplicate static percpu var names ] Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Dave Jones <davej@redhat.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: linux-mm <linux-mm@kvack.org> Cc: David S. Miller <davem@davemloft.net> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Steven Rostedt <srostedt@redhat.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Andi Kleen <andi@firstfloor.org>
2009-06-15[CPUFREQ] Only set sampling_rate_max deprecated, sampling_rate_min is usefulThomas Renninger
Update the documentation accordingly. Cleanup and use printk_once. Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com>
2009-06-15[CPUFREQ] ondemand: Uncouple minimal sampling rate from HZ in NO_HZ caseThomas Renninger
With this patch you have following minimal sampling rate restrictions: Kernel restrictions: If CONFIG_NO_HZ is set, the limit is 10ms fixed. If CONFIG_NO_HZ is not set or no_hz=off boot parameter is used, the limits depend on the CONFIG_HZ option: HZ=1000: min=20000us (20ms) HZ=250: min=80000us (80ms) HZ=100: min=200000us (200ms) HW restrictions: Do not sample/poll more often than HW latency * 100 exported by the low level cpufreq HW driver The higher value of above restrictions is the minimal sampling rate that can be set (and can be seen via ondemand/sampling_rate_min sysfs file) Default sampling rate still is HW latency * 1000, but this will now end up in lower values on latest (Intel and AMD) hardware as these can switch really fast and sampling rate mostly was limited to the 80ms or 200ms (depending on whether HZ=250 or HZ=1000 is used). Signed-off-by: Thomas Renninger <trenn@suse.de> Cc: Pallipadi Venkatesh <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] fix timer teardown in ondemand governorMathieu 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/ > (updated changelog) cpufreq fix timer teardown in ondemand governor The problem is that dbs_timer_exit() uses cancel_delayed_work() when it should use cancel_delayed_work_sync(). cancel_delayed_work() does not wait for the workqueue handler to exit. The ondemand governor does not seem to be affected because the "if (!dbs_info->enable)" check at the beginning of the workqueue handler returns immediately without rescheduling the work. The conservative governor in 2.6.30-rc has the same check as the ondemand governor, which makes things usually run smoothly. However, if the governor is quickly stopped and then started, this could lead to the following race : dbs_enable could be reenabled and multiple do_dbs_timer handlers would run. This is why a synchronized teardown is required. The following patch applies to, at least, 2.6.28.x, 2.6.29.1, 2.6.30-rc2. Depends on patch cpufreq: remove rwsem lock from CPUFREQ_GOV_STOP call Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> CC: Andrew Morton <akpm@linux-foundation.org> CC: gregkh@suse.de CC: stable@kernel.org CC: cpufreq@vger.kernel.org CC: Ingo Molnar <mingo@elte.hu> CC: rjw@sisk.pl CC: Ben Slusky <sluskyb@paranoiacs.org> Signed-off-by: Dave Jones <davej@redhat.com>
2009-05-26[CPUFREQ] fix timer teardown in conservative governorMathieu 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/ > (re-send with updated changelog) cpufreq fix timer teardown in conservative governor The problem is that dbs_timer_exit() uses cancel_delayed_work() when it should use cancel_delayed_work_sync(). cancel_delayed_work() does not wait for the workqueue handler to exit. The ondemand governor does not seem to be affected because the "if (!dbs_info->enable)" check at the beginning of the workqueue handler returns immediately without rescheduling the work. The conservative governor in 2.6.30-rc has the same check as the ondemand governor, which makes things usually run smoothly. However, if the governor is quickly stopped and then started, this could lead to the following race : dbs_enable could be reenabled and multiple do_dbs_timer handlers would run. This is why a synchronized teardown is required. Depends on patch cpufreq: remove rwsem lock from CPUFREQ_GOV_STOP call The following patch applies to 2.6.30-rc2. Stable kernels have a similar issue which should also be fixed, but the code changed between 2.6.29 and 2.6.30, so this patch only applies to 2.6.30-rc. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> CC: Andrew Morton <akpm@linux-foundation.org> CC: gregkh@suse.de CC: stable@kernel.org CC: cpufreq@vger.kernel.org CC: Ingo Molnar <mingo@elte.hu> CC: rjw@sisk.pl CC: Ben Slusky <sluskyb@paranoiacs.org> Signed-off-by: Dave Jones <davej@redhat.com>
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>
2009-02-24[CPUFREQ] conservative: remove 10x from def_sampling_rateAlexander Clouter
AMD users get particular hit by this issue (bug 8081) as it caps at typically 90 seconds as the minimum period for a frequency change. Harsh eh? Years ago I borked this buy puting the 10x in the wrong place...I fix that by removing it altogether. Signed-off-by: Alexander Clouter <alex@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24[CPUFREQ] conservative: fixup governor to function more like ondemand logicAlexander Clouter
As conservative is based off ondemand the codebases occasionally need to be resync'd. This patch, although ugly, does this. Signed-off-by: Alexander Clouter <alex@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24[CPUFREQ] conservative: fix dbs_cpufreq_notifier so freq is not lockedAlexander Clouter
When someone added the dbs_cpufreq_notifier section to the governor the code ended up causing the frequency to only fall. This is because requested_freq is tinkered with and that should only modified if it has an invlaid value due to changes in the available frequency ranges This should fix #10055. Signed-off-by: Alexander Clouter <alex@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24[CPUFREQ] conservative: amend author's email addressAlexander Clouter
Amend author's email address. Signed-off-by: Alexander Clouter <alex@digriz.org.uk> Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24[CPUFREQ] ondemand/conservative: sanitize sampling_rate restrictionsThomas Renninger
Limit sampling rate to transition_latency * 100 or kernel limits. If sampling_rate is tried to be set too low, set the lowest allowed value. Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24[CPUFREQ] ondemand/conservative: deprecate sampling_rate{min,max}Thomas Renninger
The same info can be obtained via the transition_latency sysfs file Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24[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>
2009-02-24[CPUFREQ] checkpatch cleanups for ondemand governor.Dave Jones
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24[CPUFREQ] checkpatch cleanups for freq_tableDave Jones
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24[CPUFREQ] checkpatch cleanups for userspace governorDave Jones
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24[CPUFREQ] checkpatch cleanups for cpufreq_statsDave Jones
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24[CPUFREQ] checkpatch cleanups for conservative governorDave Jones
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24[CPUFREQ] checkpatch cleanups for cpufreq coreDave Jones
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-05[CPUFREQ] Make ignore_nice_load setting of ondemand work as expected.Venkatesh Pallipadi
ondemand micro-accounting of idle time changes broke ignore_nice_load sysfs setting due to a thinko in the code. The bug entry: http://bugzilla.kernel.org/show_bug.cgi?id=12310 Reported-by: Jim Bray <jimsantelmo@gmail.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
2009-01-10Merge 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: [IA64] fix typo in cpumask_of_pcibus() x86: fix x86_32 builds for summit and es7000 arch's cpumask: use work_on_cpu in acpi-cpufreq.c for read_measured_perf_ctrs cpumask: use work_on_cpu in acpi-cpufreq.c for drv_read and drv_write cpumask: use cpumask_var_t in acpi-cpufreq.c cpumask: use work_on_cpu in acpi/cstate.c cpumask: convert struct cpufreq_policy to cpumask_var_t cpumask: replace CPUMASK_ALLOC etc with cpumask_var_t x86: cleanup remaining cpumask_t ops in smpboot code cpumask: update pci_bus_show_cpuaffinity to use new cpumask API cpumask: update local_cpus_show to use new cpumask API ia64: cpumask fix for is_affinity_mask_valid()
2009-01-06trivial: fix an -> a typos in documentation and commentsFrederik Schwarzer
It is always "an" if there is a vowel _spoken_ (not written). So it is: "an hour" (spoken vowel) but "a uniform" (spoken 'j') Signed-off-by: Frederik Schwarzer <schwarzerf@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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>