linux/drivers/cpufreq
Rafael J. Wysocki 2dd3e724b4 cpufreq: governor: Use lockless timer function
It is possible to get rid of the timer_lock spinlock used by the
governor timer function for synchronization, but a couple of races
need to be avoided.

The first race is between multiple dbs_timer_handler() instances
that may be running in parallel with each other on different
CPUs.  Namely, one of them has to queue up the work item, but it
cannot be queued up more than once.  To achieve that,
atomic_inc_return() can be used on the skip_work field of
struct cpu_common_dbs_info.

The second race is between an already running dbs_timer_handler()
and gov_cancel_work().  In that case the dbs_timer_handler() might
not notice the skip_work incrementation in gov_cancel_work() and
it might queue up its work item after gov_cancel_work() had
returned (and that work item would corrupt skip_work going
forward).  To prevent that from happening, gov_cancel_work()
can be made wait for the timer function to complete (on all CPUs)
right after skip_work has been incremented.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2015-12-09 22:26:13 +01:00
..
acpi-cpufreq.c cpufreq: acpi_cpufreq: prevent crash on reading freqdomain_cpus 2015-10-08 21:47:13 +02:00
amd_freq_sensitivity.c cpufreq: AMD "frequency sensitivity feedback" powersave bias for ondemand governor 2013-04-10 13:19:26 +02:00
arm_big_little_dt.c PM / OPP: Prefix exported opp routines with dev_pm_opp_ 2015-09-15 02:03:16 +02:00
arm_big_little.c cpufreq: arm_big_little: fix frequency check when bL switcher is active 2015-11-02 01:58:27 +01:00
arm_big_little.h PM / OPP: Prefix exported opp routines with dev_pm_opp_ 2015-09-15 02:03:16 +02:00
at32ap-cpufreq.c cpufreq: at32ap: don't declare local variable as static 2014-04-07 14:31:33 +02:00
blackfin-cpufreq.c cpufreq: Remove cpufreq_generic_exit() 2014-03-12 01:06:00 +01:00
cppc_cpufreq.c cpufreq: CPPC: Initialize and check CPUFreq CPU co-ord type correctly 2015-11-23 22:21:18 +01:00
cpufreq_conservative.c cpufreq: governor: Pass policy as argument to ->gov_dbs_timer() 2015-12-07 02:20:22 +01:00
cpufreq_governor.c cpufreq: governor: Use lockless timer function 2015-12-09 22:26:13 +01:00
cpufreq_governor.h cpufreq: governor: Use lockless timer function 2015-12-09 22:26:13 +01:00
cpufreq_ondemand.c cpufreq: ondemand: update update_sampling_rate() to make it more efficient 2015-12-09 22:26:12 +01:00
cpufreq_performance.c cpufreq: Clean up header files included in the core 2013-08-07 23:34:09 +02:00
cpufreq_powersave.c cpufreq: Clean up header files included in the core 2013-08-07 23:34:09 +02:00
cpufreq_stats.c cpufreq: stats: drop unnecessary locking 2015-01-23 23:06:45 +01:00
cpufreq_userspace.c cpufreq / governor: Remove fossil comment 2013-10-17 23:00:20 +02:00
cpufreq-dt.c PM / OPP: Prefix exported opp routines with dev_pm_opp_ 2015-09-15 02:03:16 +02:00
cpufreq-nforce2.c cpufreq: nforce2: Fix typo in comment to function nforce2_init() 2015-06-15 15:45:24 +02:00
cpufreq.c cpufreq: use last policy after online for drivers with ->setpolicy 2015-12-02 23:50:33 +01:00
cris-artpec3-cpufreq.c cpufreq: create another field .flags in cpufreq_frequency_table 2014-04-07 14:43:50 +02:00
cris-etraxfs-cpufreq.c cpufreq: create another field .flags in cpufreq_frequency_table 2014-04-07 14:43:50 +02:00
davinci-cpufreq.c cpufreq: drop owner assignment from platform_drivers 2014-10-20 16:20:24 +02:00
dbx500-cpufreq.c cpufreq: drop owner assignment from platform_drivers 2014-10-20 16:20:24 +02:00
e_powersaver.c ACPI / processor: Drop an unused argument of a cleanup routine 2015-07-22 22:11:16 +02:00
elanfreq.c cpufreq: Use cpufreq_for_each_* macros for frequency table iteration 2014-04-30 00:06:21 +02:00
exynos5440-cpufreq.c PM / OPP: Prefix exported opp routines with dev_pm_opp_ 2015-09-15 02:03:16 +02:00
freq_table.c cpufreq: Allow drivers to enable boost support after registering driver 2015-08-07 03:25:23 +02:00
gx-suspmod.c cpufreq: gx-suspmod: Fix two typos in two comments 2015-06-15 15:46:15 +02:00
highbank-cpufreq.c Merge branch 'mailbox-for-linus' of git://git.linaro.org/landing-teams/working/fujitsu/integration 2014-10-21 11:21:19 -07:00
hisi-acpu-cpufreq.c cpufreq: hisilicon: add acpu driver 2015-04-02 02:24:54 +02:00
ia64-acpi-cpufreq.c cpufreq: ia64: Fix a memory leak in acpi_cpufreq_cpu_exit() 2015-07-22 22:27:40 +02:00
imx6q-cpufreq.c Merge branch 'pm-opp' 2015-11-02 00:54:37 +01:00
integrator-cpufreq.c cpufreq: integrator: Fix module autoload for OF platform driver 2015-09-25 23:29:35 +02:00
intel_pstate.c intel_pstate: Fix "performance" mode behavior with HWP enabled 2015-11-25 23:37:44 +01:00
Kconfig cpufreq: qoriq: rename the driver 2015-03-18 22:35:16 +01:00
Kconfig.arm cpufreq: SCPI: Depend on SCPI clk driver 2015-11-23 23:50:27 +01:00
Kconfig.powerpc cpufreq: qoriq: rename the driver 2015-03-18 22:35:16 +01:00
Kconfig.x86 Revert "cpufreq: intel_pstate: Use ACPI perf configuration" 2015-11-19 00:20:42 +01:00
kirkwood-cpufreq.c cpufreq: drop owner assignment from platform_drivers 2014-10-20 16:20:24 +02:00
longhaul.c Update/Remove soon-to-be-dead email address 2014-12-19 12:56:15 -08:00
longhaul.h cpufreq: delete __cpuinit usage from all cpufreq files 2013-07-14 19:36:57 -04:00
longrun.c cpufreq: add new routine cpufreq_verify_within_cpu_limits() 2013-10-16 00:50:23 +02:00
loongson2_cpufreq.c CPUFREQ: Loongson2: Fix broken build due to incorrect include. 2015-08-03 09:24:59 +02:00
ls1x-cpufreq.c MIPS: Loongson: Naming style cleanup and rework 2015-06-21 21:53:59 +02:00
Makefile ARM: SoC driver updates for v4.4 2015-11-10 15:00:03 -08:00
maple-cpufreq.c cpufreq: create another field .flags in cpufreq_frequency_table 2014-04-07 14:43:50 +02:00
mt8173-cpufreq.c PM / OPP: Prefix exported opp routines with dev_pm_opp_ 2015-09-15 02:03:16 +02:00
omap-cpufreq.c cpufreq: drop owner assignment from platform_drivers 2014-10-20 16:20:24 +02:00
p4-clockmod.c p4-clockmod: Replace cpu_sibling_mask() with topology_sibling_cpumask() 2015-05-27 15:22:16 +02:00
pasemi-cpufreq.c cpufreq: Use cpufreq_for_each_* macros for frequency table iteration 2014-04-30 00:06:21 +02:00
pcc-cpufreq.c cpufreq: pcc: Enable autoload of pcc-cpufreq for ACPI processors 2014-11-14 00:16:25 +01:00
pmac32-cpufreq.c powerpc: Remove powerpc specific cmd_line 2014-10-02 17:33:55 +10:00
pmac64-cpufreq.c of: Migrate of_find_node_by_name() users to for_each_node_by_name() 2014-06-26 17:12:24 +01:00
powernow-k6.c Update/Remove soon-to-be-dead email address 2014-12-19 12:56:15 -08:00
powernow-k7.c ACPI / processor: Drop an unused argument of a cleanup routine 2015-07-22 22:11:16 +02:00
powernow-k7.h
powernow-k8.c ACPI / processor: Drop an unused argument of a cleanup routine 2015-07-22 22:11:16 +02:00
powernow-k8.h cpufreq: powernow-k8: Suppress checkpatch warnings 2014-05-17 01:27:01 +02:00
powernv-cpufreq.c cpufreq : powernv: Report Pmax throttling if capped below nominal frequency 2015-09-26 03:03:06 +02:00
ppc_cbe_cpufreq_pervasive.c cpufreq: powerpc/platforms/cell: move cpufreq driver to drivers/cpufreq 2013-04-10 13:19:26 +02:00
ppc_cbe_cpufreq_pmi.c cpufreq: remove redundant CPUFREQ_INCOMPATIBLE notifier event 2015-09-01 15:50:38 +02:00
ppc_cbe_cpufreq.c cpufreq: Use cpufreq_for_each_* macros for frequency table iteration 2014-04-30 00:06:21 +02:00
ppc_cbe_cpufreq.h cpufreq: powerpc/platforms/cell: move cpufreq driver to drivers/cpufreq 2013-04-10 13:19:26 +02:00
pxa2xx-cpufreq.c cpufreq: pxa: make pxa_freqs arrays const 2015-05-05 00:49:38 +02:00
pxa3xx-cpufreq.c cpufreq: Remove cpufreq_generic_exit() 2014-03-12 01:06:00 +01:00
qoriq-cpufreq.c cpufreq: qoriq: optimize the CPU frequency switching time 2015-06-15 15:47:28 +02:00
s3c24xx-cpufreq-debugfs.c cpufreq: s3c24xx: move cpufreq driver to drivers/cpufreq 2013-05-20 23:04:28 +09:00
s3c24xx-cpufreq.c cpufreq: s3c: remove last use of resume_clocks callback 2015-02-19 06:36:53 +01:00
s3c64xx-cpufreq.c cpufreq: Use cpufreq_for_each_* macros for frequency table iteration 2014-04-30 00:06:21 +02:00
s3c2410-cpufreq.c cpufreq: s3c24xx: Remove some dead code 2014-07-19 04:24:59 +09:00
s3c2412-cpufreq.c cpufreq: s3c24xx: Remove some dead code 2014-07-19 04:24:59 +09:00
s3c2416-cpufreq.c cpufreq: s3c: remove incorrect __init annotations 2015-02-19 06:36:53 +01:00
s3c2440-cpufreq.c cpufreq: s3c24xx: Remove some dead code 2014-07-19 04:24:59 +09:00
s5pv210-cpufreq.c cpufreq: s5pv210-cpufreq: fix wrong do_div() usage 2015-11-05 22:50:48 +01:00
sa1100-cpufreq.c cpufreq: Mark ARM drivers with CPUFREQ_NEED_INITIAL_FREQ_CHECK flag 2014-01-06 14:17:25 +01:00
sa1110-cpufreq.c cpufreq: sa1110: set memory type for h3600 2014-07-16 14:30:17 +02:00
sc520_freq.c cpufreq: create another field .flags in cpufreq_frequency_table 2014-04-07 14:43:50 +02:00
scpi-cpufreq.c cpufreq: arm_big_little: add SCPI interface driver 2015-09-28 11:53:38 +01:00
sfi-cpufreq.c cpufreq: sfi: use kmemdup rather than duplicating its implementation 2015-09-01 15:51:15 +02:00
sh-cpufreq.c cpufreq: Convert existing drivers to use cpufreq_freq_transition_{begin|end} 2014-03-26 16:41:41 +01:00
sparc-us2e-cpufreq.c cpufreq: add 'freq_table' in struct cpufreq_policy 2014-03-12 01:06:00 +01:00
sparc-us3-cpufreq.c cpufreq: add 'freq_table' in struct cpufreq_policy 2014-03-12 01:06:00 +01:00
spear-cpufreq.c cpufreq: drop owner assignment from platform_drivers 2014-10-20 16:20:24 +02:00
speedstep-centrino.c cpufreq: Make linux-pm@vger.kernel.org official mailing list 2014-05-01 01:15:32 +02:00
speedstep-ich.c speedstep-ich: Replace cpu_sibling_mask() with topology_sibling_cpumask() 2015-05-27 15:22:16 +02:00
speedstep-lib.c cpufreq: speedstep-lib: Use monotonic clock 2015-09-01 15:51:43 +02:00
speedstep-lib.h
speedstep-smi.c cpufreq: speedstep-smi: enable interrupts when waiting 2015-02-12 02:02:52 +01:00
tegra20-cpufreq.c cpufreq: tegra20: remove superfluous CONFIG_PM ifdefs 2015-09-26 03:00:57 +02:00
tegra124-cpufreq.c cpufreq: Add cpufreq driver for Tegra124 2015-07-16 09:34:09 +02:00
unicore2-cpufreq.c cpufreq: unicore32: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO 2014-04-21 23:42:27 +02:00
vexpress-spc-cpufreq.c cpufreq: drop owner assignment from platform_drivers 2014-10-20 16:20:24 +02:00