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path: root/drivers/cpufreq/cpufreq_ondemand.c
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2013-06-25cpufreq: fix NULL pointer deference at od_set_powersave_bias()Jacob Shin
When initializing the default powersave_bias value, we need to first make sure that this policy is running the ondemand governor. Reported-and-tested-by: Tim Gardner <tim.gardner@canonical.com> Signed-off-by: Jacob Shin <jacob.shin@amd.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-13cpufreq, ondemand: Remove leftover debug lineBorislav Petkov
I don't see how the virtual address of the tuners pointer would be of any help to anyone so remove it. Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-10cpufreq: ondemand: allow custom powersave_bias_target handler to be registeredJacob Shin
This allows for another [arch specific] driver to hook into existing powersave bias function of the ondemand governor. i.e. This allows AMD specific powersave bias function (in a separate AMD specific driver) to aid ondemand governor's frequency transition decisions. Signed-off-by: Jacob Shin <jacob.shin@amd.com> Acked-by: Thomas Renninger <trenn@suse.de> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-31cpufreq: governors: Calculate iowait time only when necessaryStratos Karafotis
Currently we always calculate the CPU iowait time and add it to idle time. If we are in ondemand and we use io_is_busy, we re-calculate iowait time and we subtract it from idle time. With this patch iowait time is calculated only when necessary avoiding the double call to get_cpu_iowait_time_us. We use a parameter in function get_cpu_idle_time to distinguish when the iowait time will be added to idle time or not, without the need of keeping the prev_io_wait. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.,org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-31cpufreq: governors: Avoid unnecessary per cpu timer interruptsViresh Kumar
Following patch has introduced per cpu timers or works for ondemand and conservative governors. commit 2abfa876f1117b0ab45f191fb1f82c41b1cbc8fe Author: Rickard Andersson <rickard.andersson@stericsson.com> Date: Thu Dec 27 14:55:38 2012 +0000 cpufreq: handle SW coordinated CPUs This causes additional unnecessary interrupts on all cpus when the load is recently evaluated by any other cpu. i.e. When load is recently evaluated by cpu x, we don't really need any other cpu to evaluate this load again for the next sampling_rate time. Some sort of code is present to avoid that but we are still getting timer interrupts for all cpus. A good way of avoiding this would be to modify delays for all cpus (policy->cpus) whenever any cpu has evaluated load. This patch does this change and some related code cleanup. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-31cpufreq: ondemand: Don't update sample_type if we don't evaluate load againViresh Kumar
Because we have per cpu timer now, we check if we need to evaluate load again or not (In case it is recently evaluated). Here the 2nd cpu which got timer interrupt updates core_dbs_info->sample_type irrespective of load evaluation is required or not. Which is wrong as the first cpu is dependent on this variable set to an older value. Moreover it would be best in this case to schedule 2nd cpu's timer to sampling_rate instead of freq_lo or hi as that must be managed by the other cpu. In case the other cpu idles in between then also we wouldn't loose much power. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-03-31cpufreq: governor: Implement per policy instances of governorsViresh Kumar
Currently, there can't be multiple instances of single governor_type. If we have a multi-package system, where we have multiple instances of struct policy (per package), we can't have multiple instances of same governor. i.e. We can't have multiple instances of ondemand governor for multiple packages. Governors directory in sysfs is created at /sys/devices/system/cpu/cpufreq/ governor-name/. Which again reflects that there can be only one instance of a governor_type in the system. This is a bottleneck for multicluster system, where we want different packages to use same governor type, but with different tunables. This patch uses the infrastructure provided by earlier patch and implements init/exit routines for ondemand and conservative governors. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-02-09cpufreq: ondemand: Fix typos in commentsStratos Karafotis
Fix some typos in comments. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-02-09cpufreq: ondemand: Replace down_differential tuner with adj_up_thresholdStratos Karafotis
In order to avoid the calculation of up_threshold - down_differential every time that the frequency must be decreased, we replace the down_differential tuner with the adj_up_threshold which keeps the difference across multiple checks. Update the adj_up_threshold only when the up_theshold is also updated. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-02-02cpufreq: governors: Remove code redundancy between governorsViresh Kumar
With the inclusion of following patches: 9f4eb10 cpufreq: conservative: call dbs_check_cpu only when necessary 772b4b1 cpufreq: ondemand: call dbs_check_cpu only when necessary code redundancy between the conservative and ondemand governors is introduced again, so get rid of it. [rjw: Changelog] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Fabio Baltieri <fabio.baltieri@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-02-01cpufreq: governors: fix misuse of cdbs.cpuFabio Baltieri
Fix governors code to set all cpu's cdbs->cpu to the the actual cpu id and use cur_policy->cpu istead of cdbs->cpu to track current governor's leader cpu. Reported-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Fabio Baltieri <fabio.baltieri@linaro.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-02-01cpufreq: governors: implement generic policy_is_sharedFabio Baltieri
Implement a generic helper function policy_is_shared() to replace the current dbs_sw_coordinated_cpus() at cpufreq level, so that it can be used by code other than cpufreq governors. Suggested-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Fabio Baltieri <fabio.baltieri@linaro.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-02-01cpufreq: ondemand: use all CPUs in update_sampling_rateFabio Baltieri
Modify update_sampling_rate() to check, and eventually immediately schedule, all CPU's do_dbs_timer delayed work. This is required in case of software coordinated CPUs, as we now have a separate delayed work for each CPU. Signed-off-by: Fabio Baltieri <fabio.baltieri@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-02-01cpufreq: ondemand: call dbs_check_cpu only when necessaryFabio Baltieri
Modify ondemand timer to not resample CPU utilization if recently sampled from another SW coordinated core. Signed-off-by: Fabio Baltieri <fabio.baltieri@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-02-01cpufreq: handle SW coordinated CPUsRickard Andersson
This patch fixes a bug that occurred when we had load on a secondary CPU and the primary CPU was sleeping. Only one sampling timer was spawned and it was spawned as a deferred timer on the primary CPU, so when a secondary CPU had a change in load this was not detected by the cpufreq governor (both ondemand and conservative). This patch make sure that deferred timers are run on all CPUs in the case of software controlled CPUs that run on the same frequency. Signed-off-by: Rickard Andersson <rickard.andersson@stericsson.com> Signed-off-by: Fabio Baltieri <fabio.baltieri@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-11-27cpufreq: ondemand: update sampling rate only on right CPUsFabio Baltieri
Fix cpufreq_gov_ondemand to skip CPU where another governor is used. The bug present itself as NULL pointer access on the mutex_lock() call, an can be reproduced on an SMP machine by setting the default governor to anything other than ondemand, setting a single CPU's governor to ondemand, then changing the sample rate by writing on: > /sys/devices/system/cpu/cpufreq/ondemand/sampling_rate Backtrace: Nov 26 17:36:54 balto kernel: [ 839.585241] BUG: unable to handle kernel NULL pointer dereference at (null) Nov 26 17:36:54 balto kernel: [ 839.585311] IP: [<ffffffff8174e082>] __mutex_lock_slowpath+0xb2/0x170 [snip] Nov 26 17:36:54 balto kernel: [ 839.587005] Call Trace: Nov 26 17:36:54 balto kernel: [ 839.587030] [<ffffffff8174da82>] mutex_lock+0x22/0x40 Nov 26 17:36:54 balto kernel: [ 839.587067] [<ffffffff81610b8f>] store_sampling_rate+0xbf/0x150 Nov 26 17:36:54 balto kernel: [ 839.587110] [<ffffffff81031e9c>] ? __do_page_fault+0x1cc/0x4c0 Nov 26 17:36:54 balto kernel: [ 839.587153] [<ffffffff813309bf>] kobj_attr_store+0xf/0x20 Nov 26 17:36:54 balto kernel: [ 839.587192] [<ffffffff811bb62d>] sysfs_write_file+0xcd/0x140 Nov 26 17:36:54 balto kernel: [ 839.587234] [<ffffffff8114c12c>] vfs_write+0xac/0x180 Nov 26 17:36:54 balto kernel: [ 839.587271] [<ffffffff8114c472>] sys_write+0x52/0xa0 Nov 26 17:36:54 balto kernel: [ 839.587306] [<ffffffff810321ce>] ? do_page_fault+0xe/0x10 Nov 26 17:36:54 balto kernel: [ 839.587345] [<ffffffff81751202>] system_call_fastpath+0x16/0x1b Signed-off-by: Fabio Baltieri <fabio.baltieri@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-11-23cpufreq: ondemand: fix wrong delay sampling rateFabio Baltieri
Restore the correct delay value for ondemand's od_dbs_timer, as it was changed erroneously in commit 83f0e55 (cpufreq: governors: remove redundant code). Signed-off-by: Fabio Baltieri <fabio.baltieri@linaro.org> Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-11-14cpufreq: governors: remove redundant codeViresh Kumar
Initially ondemand governor was written and then using its code conservative governor is written. It used a lot of code from ondemand governor, but copy of code was created instead of using the same routines from both governors. Which increased code redundancy, which is difficult to manage. This patch is an attempt to move common part of both the governors to cpufreq_governor.c file to come over above mentioned issues. This shouldn't change anything from functionality point of view. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-11-14cpufreq: Move common part from governors to separate file, v2viresh kumar
Multiple cpufreq governers have defined similar get_cpu_idle_time_***() routines. These routines must be moved to some common place, so that all governors can use them. So moving them to cpufreq_governor.c, which seems to be a better place for keeping these routines. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-03Merge tag 'pm-for-3.7-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael J Wysocki: - Improved system suspend/resume and runtime PM handling for the SH TMU, CMT and MTU2 clock event devices (also used by ARM/shmobile). - Generic PM domains framework extensions related to cpuidle support and domain objects lookup using names. - ARM/shmobile power management updates including improved support for the SH7372's A4S power domain containing the CPU core. - cpufreq changes related to AMD CPUs support from Matthew Garrett, Andre Przywara and Borislav Petkov. - cpu0 cpufreq driver from Shawn Guo. - cpufreq governor fixes related to the relaxing of limit from Michal Pecio. - OMAP cpufreq updates from Axel Lin and Richard Zhao. - cpuidle ladder governor fixes related to the disabling of states from Carsten Emde and me. - Runtime PM core updates related to the interactions with the system suspend core from Alan Stern and Kevin Hilman. - Wakeup sources modification allowing more helper functions to be called from interrupt context from John Stultz and additional diagnostic code from Todd Poynor. - System suspend error code path fix from Feng Hong. Fixed up conflicts in cpufreq/powernow-k8 that stemmed from the workqueue fixes conflicting fairly badly with the removal of support for hardware P-state chips. The changes were independent but somewhat intertwined. * tag 'pm-for-3.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (76 commits) Revert "PM QoS: Use spinlock in the per-device PM QoS constraints code" PM / Runtime: let rpm_resume() succeed if RPM_ACTIVE, even when disabled, v2 cpuidle: rename function name "__cpuidle_register_driver", v2 cpufreq: OMAP: Check IS_ERR() instead of NULL for omap_device_get_by_hwmod_name cpuidle: remove some empty lines PM: Prevent runtime suspend during system resume PM QoS: Use spinlock in the per-device PM QoS constraints code PM / Sleep: use resume event when call dpm_resume_early cpuidle / ACPI : move cpuidle_device field out of the acpi_processor_power structure ACPI / processor: remove pointless variable initialization ACPI / processor: remove unused function parameter cpufreq: OMAP: remove loops_per_jiffy recalculate for smp sections: fix section conflicts in drivers/cpufreq cpufreq: conservative: update frequency when limits are relaxed cpufreq / ondemand: update frequency when limits are relaxed properly __init-annotate pm_sysrq_init() cpufreq: Add a generic cpufreq-cpu0 driver PM / OPP: Initialize OPP table from device tree ARM: add cpufreq transiton notifier to adjust loops_per_jiffy for smp cpufreq: Remove support for hardware P-state chips from powernow-k8 ...
2012-09-14cpufreq / ondemand: update frequency when limits are relaxedMichal Pecio
Reevaluate CPU load and update frequency immediately whenever limits are changed. Currently ondemand doesn't do that when limits are relaxed, wasting power on systems with relatively low sampling rate. Signed-off-by: Michal Pecio <mpecio@nvidia.com> Reviewed-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-08-21workqueue: make deferrable delayed_work initializer names consistentTejun Heo
Initalizers for deferrable delayed_work are confused. * __DEFERRED_WORK_INITIALIZER() * DECLARE_DEFERRED_WORK() * INIT_DELAYED_WORK_DEFERRABLE() Rename them to * __DEFERRABLE_WORK_INITIALIZER() * DECLARE_DEFERRABLE_WORK() * INIT_DEFERRABLE_WORK() This patch doesn't cause any functional changes. Signed-off-by: Tejun Heo <tj@kernel.org>
2012-03-01[CPUFREQ] CPUfreq ondemand: update sampling rate without waiting for next ↵MyungJoo Ham
sampling When a new sampling rate is shorter than the current one, (e.g., 1 sec --> 10 ms) regardless how short the new one is, the current ondemand mechanism wait for the previously set timer to be expired. For example, if the user has just expressed that the sampling rate should be 10 ms from now and the previous was 1000 ms, the new rate may become effective 999 ms later, which could be not acceptable for the user if the user has intended to speed up sampling because the system is expected to react to CPU load fluctuation quickly from __now__. In order to address this issue, we need to cancel the previously set timer (schedule_delayed_work) and reset the timer if resetting timer is expected to trigger the delayed_work ealier. Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Dave Jones <davej@redhat.com>
2012-01-12Merge 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: (23 commits) [CPUFREQ] EXYNOS: Removed useless headers and codes [CPUFREQ] EXYNOS: Make EXYNOS common cpufreq driver [CPUFREQ] powernow-k8: Update copyright, maintainer and documentation information [CPUFREQ] powernow-k8: Fix indexing issue [CPUFREQ] powernow-k8: Avoid Pstate MSR accesses on systems supporting CPB [CPUFREQ] update lpj only if frequency has changed [CPUFREQ] cpufreq:userspace: fix cpu_cur_freq updation [CPUFREQ] Remove wall variable from cpufreq_gov_dbs_init() [CPUFREQ] EXYNOS4210: cpufreq code is changed for stable working [CPUFREQ] EXYNOS4210: Update frequency table for cpu divider [CPUFREQ] EXYNOS4210: Remove code about bus on cpufreq [CPUFREQ] s3c64xx: Use pr_fmt() for consistent log messages cpufreq: OMAP: fixup for omap_device changes, include <linux/module.h> cpufreq: OMAP: fix freq_table leak cpufreq: OMAP: put clk if cpu_init failed cpufreq: OMAP: only supports OPP library cpufreq: OMAP: dont support !freq_table cpufreq: OMAP: deny initialization if no mpudev cpufreq: OMAP: move clk name decision to init cpufreq: OMAP: notify even with bad boot frequency ...
2011-12-19Merge branch 'sched/core' of ↵Martin Schwidefsky
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into cputime-tip Conflicts: drivers/cpufreq/cpufreq_conservative.c drivers/cpufreq/cpufreq_ondemand.c drivers/macintosh/rack-meter.c fs/proc/stat.c fs/proc/uptime.c kernel/sched/core.c
2011-12-15[S390] cputime: add sparse checking and cleanupMartin Schwidefsky
Make cputime_t and cputime64_t nocast to enable sparse checking to detect incorrect use of cputime. Drop the cputime macros for simple scalar operations. The conversion macros are still needed. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-12-09[CPUFREQ] Remove wall variable from cpufreq_gov_dbs_init()Kamalesh Babulal
CPUFREQ Remove wall variable from cpufreq_gov_dbs_init() Remove wall variable from cpufreq_gov_dbs_init() as get_cpu_idle_time_us() no longer updates the last_update_time unconditionally. Passing non-NULL last_update_time address will result in accounting additional idle time with update_ts_time_stats() before returning idle_sleeptime. Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Signed-off-by: Dave Jones <davej@redhat.com> -- drivers/cpufreq/cpufreq_ondemand.c | 3 +-- 1 files changed, 1 insertions(+), 2 deletions(-)
2011-12-06sched/accounting: Change cpustat fields to an arrayGlauber Costa
This patch changes fields in cpustat from a structure, to an u64 array. Math gets easier, and the code is more flexible. Signed-off-by: Glauber Costa <glommer@parallels.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Paul Tuner <pjt@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1322498719-2255-2-git-send-email-glommer@parallels.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-10-26Merge branch 'timers-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) time, s390: Get rid of compile warning dw_apb_timer: constify clocksource name time: Cleanup old CONFIG_GENERIC_TIME references that snuck in time: Change jiffies_to_clock_t() argument type to unsigned long alarmtimers: Fix error handling clocksource: Make watchdog reset lockless posix-cpu-timers: Cure SMP accounting oddities s390: Use direct ktime path for s390 clockevent device clockevents: Add direct ktime programming function clockevents: Make minimum delay adjustments configurable nohz: Remove "Switched to NOHz mode" debugging messages proc: Consider NO_HZ when printing idle and iowait times nohz: Make idle/iowait counter update conditional nohz: Fix update_ts_time_stat idle accounting cputime: Clean up cputime_to_usecs and usecs_to_cputime macros alarmtimers: Rework RTC device selection using class interface alarmtimers: Add try_to_cancel functionality alarmtimers: Add more refined alarm state tracking alarmtimers: Remove period from alarm structure alarmtimers: Remove interval cap limit hack ...
2011-09-08nohz: Fix update_ts_time_stat idle accountingMichal Hocko
update_ts_time_stat currently updates idle time even if we are in iowait loop at the moment. The only real users of the idle counter (via get_cpu_idle_time_us) are CPU governors and they expect to get cumulative time for both idle and iowait times. The value (idle_sleeptime) is also printed to userspace by print_cpu but it prints both idle and iowait times so the idle part is misleading. Let's clean this up and fix update_ts_time_stat to account both counters properly and update consumers of idle to consider iowait time as well. If we do this we might use get_cpu_{idle,iowait}_time_us from other contexts as well and we will get expected values. Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Dave Jones <davej@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Alexey Dobriyan <adobriyan@gmail.com> Link: http://lkml.kernel.org/r/e9c909c221a8da402c4da07e4cd968c3218f8eb1.1314172057.git.mhocko@suse.cz Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-08-08Fix documentation and comment typo 'no_hz'Paul Bolle
Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Acked-by: Len Brown <len.brown@intel.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-03-16[CPUFREQ] Remove unneeded locksThomas Renninger
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[CPUFREQ] Remove old, deprecated per cpu ondemand/conservative sysfs filesThomas Renninger
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[CPUFREQ] Remove deprecated sysfs file sampling_rate_maxThomas Renninger
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[CPUFREQ] calculate delay after dbs_check_cpuVincent Guittot
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>
2011-01-26cpufreq: use system_wq instead of dedicated workqueuesTejun Heo
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
2010-10-22[CPUFREQ] add sampling_down_factor tunable to improve ondemand performanceDavid C Niemi
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>
2010-08-03[CPUFREQ] ondemand: don't synchronize sample rate unless multiple cpus presentJocelyn Falempe
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[CPUFREQ] ondemand: Refactor frequency increase codeMike Chan
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>
2010-05-18Merge branch 'x86-cpu-for-linus' of ↵Linus Torvalds
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
2010-05-09ondemand: Make the iowait-is-busy time a sysfs tunableArjan van de Ven
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>
2010-05-09ondemand: Solve a big performance issue by counting IOWAIT time as busyArjan van de Ven
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>
2010-04-09cpufreq: Unify sysfs attribute definition macrosBorislav Petkov
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>
2010-01-13[CPUFREQ] Fix ondemand to not request targets outside policy limitsNagananda.Chumbalkar@hp.com
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
2009-11-18[CPUFREQ] Resolve time unit thinko in ondemand/conservative govsPallipadi, Venkatesh
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>
2009-09-18Merge 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
2009-09-01[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>
2009-08-14Merge 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>
2009-07-07[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>
2009-07-07[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>