Commit Graph

73 Commits

Author SHA1 Message Date
Stratos Karafotis
c88883cd54 cpufreq: conservative: Fix typos in comments
Fix a couple of 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>
2013-02-09 12:56:19 +01:00
Viresh Kumar
4447266b84 cpufreq: governors: Remove code redundancy between governors
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>
2013-02-02 01:02:44 +01:00
Fabio Baltieri
09dca5ae75 cpufreq: governors: fix misuse of cdbs.cpu
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>
2013-02-02 00:01:16 +01:00
Fabio Baltieri
2624f90c16 cpufreq: governors: implement generic policy_is_shared
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>
2013-02-02 00:01:16 +01:00
Fabio Baltieri
66df2a01df cpufreq: conservative: call dbs_check_cpu only when necessary
Modify conservative 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>
2013-02-02 00:01:13 +01:00
Rickard Andersson
2abfa876f1 cpufreq: handle SW coordinated CPUs
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>
2013-02-02 00:01:13 +01:00
Viresh Kumar
4471a34f9a cpufreq: governors: remove redundant code
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>
2012-11-15 00:33:07 +01:00
viresh kumar
2aacdfff9c cpufreq: Move common part from governors to separate file, v2
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>
2012-11-15 00:33:06 +01:00
Linus Torvalds
16642a2e7b Power management updates for 3.7-rc1
* 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.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.18 (GNU/Linux)
 
 iQIcBAABAgAGBQJQa1rRAAoJEKhOf7ml8uNsYZ0P/2RZ71sgLWcUCfr0yHaiZeOd
 2GxEYSZ+9BZJHADgoAK/bHRTv8crm40Y2RkbaWbxPDRNuE4SutbvNTGTlJSAguSD
 yHkU/6AFC7u8Jwq+afsWIdGX7eHd78zPpj6EVtVtjHM903WDwbMU2vUz7tQ+fFa+
 ZZ7eydq9j0ec0OoH3UeNhet7JSOpT5BSLgjmIkHMBgIvTxNVDbkB31QUxnUxocxn
 k6S2wQaUSJJWGMLksRRNrhwLq+cGYwTsaOtG/KzRLH1raUyn33B5pcZr0aqhOkjg
 ClaCks3V8o3vRghSwOPB5aVXzjBKvM3UnSyJNIl+FeCeyWuwSNbkEFdA/e7oPuxG
 UsW6dcHiuVo6Ir4+zhd9+lN+/AcPTChO5b7lbU8qRF4ce04czWlUY/KzJjaM+YOE
 CKGq6eX9AHwFjE+h4+VcCXgmzcioiS8Y/CPz13u8N1y0zzwW+ftjb12K+7lVBEG1
 fhrePKHgLw3kJ9LqGpR+4vVur7C+rCf6WwCReTY2vXXVYJ+SuKWTRI4zAjTPXtHa
 i9dpMRASpF+ScRYBcgwIpv789WuHATFKqdBSinZUKBaxQZ5flJ2qIrfqN5VeAejh
 oQs/zZCdIuAtFKqVycQ0L42YxFNKgPFKQErUCSu3M5OuZLlLVLu7yQvIo2Xmo9qf
 Hcrpvo5K+w29YkiwGP9e
 =rbCk
 -----END PGP SIGNATURE-----

Merge tag 'pm-for-3.7-rc1' of 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
  ...
2012-10-02 18:32:35 -07:00
Michal Pecio
2d8fced75c cpufreq: conservative: update frequency when limits are relaxed
Reevaluate CPU load and update frequency immediately whenever limits
are changed. Currently conservative 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>
2012-09-14 21:07:48 +02:00
Amit Daniel Kachhap
2d175069f2 PM / cpufreq: Initialise the cpu field during conservative governor start
This change initialises the cpu id field of cs_cpu_dbs_info structure in
conservative governor and keep this consistent with other governors.
Similar initialisation is present in ondemand governor.

Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-09-04 01:37:47 +02:00
Tejun Heo
203b42f731 workqueue: make deferrable delayed_work initializer names consistent
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>
2012-08-21 13:18:23 -07:00
Martin Schwidefsky
612ef28a04 Merge branch 'sched/core' of 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
2011-12-19 19:23:15 +01:00
Martin Schwidefsky
648616343c [S390] cputime: add sparse checking and cleanup
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>
2011-12-15 14:56:19 +01:00
Glauber Costa
3292beb340 sched/accounting: Change cpustat fields to an array
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>
2011-12-06 09:06:38 +01:00
Michal Hocko
6beea0cda8 nohz: Fix update_ts_time_stat idle accounting
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>
2011-09-08 11:10:55 +02:00
Thomas Renninger
326c86deae [CPUFREQ] Remove unneeded locks
There cannot be any concurrent access to these through
different cpu sysfs files anymore, because these tunables
are now all global (not per cpu).

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

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

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

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
CC: cpufreq@vger.kernel.org
2011-03-16 17:54:32 -04:00
Joe Perches
2feb690c20 [CPUFREQ] drivers/cpufreq: Remove unnecessary semicolons
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2011-03-16 17:54:31 -04:00
Tejun Heo
57df5573a5 cpufreq: use system_wq instead of dedicated workqueues
With cmwq, there's no reason for cpufreq drivers to use separate
workqueues.  Remove the dedicated workqueues from cpufreq_conservative
and cpufreq_ondemand and use system_wq instead.  The work items are
already sync canceled on stop, so it's already guaranteed that no work
is running on module exit.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Dave Jones <davej@redhat.com>
Cc: cpufreq@vger.kernel.org
2011-01-26 12:12:50 +01:00
H. Peter Anvin
d7be0ce6af Merge commit 'v2.6.34-rc6' into x86/cpu 2010-05-08 14:59:58 -07:00
Borislav Petkov
6dad2a2964 cpufreq: Unify sysfs attribute definition macros
Multiple modules used to define those which are with identical
functionality and were needlessly replicated among the different cpufreq
drivers. Push them into the header and remove duplication.

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

Reported-by: Jean-Christian Goussard <jeanchristian.goussard@sfr.fr>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Dave Jones <davej@redhat.com>
2010-03-31 12:00:22 -04:00
Thomas Renninger
49b015ce38 [CPUFREQ] Use global sysfs cpufreq structure for conservative governor tunings
Same adustments that have been added to the ondemand recently.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
2009-11-24 13:33:34 -05:00
Pallipadi, Venkatesh
54c9a35d9f [CPUFREQ] Resolve time unit thinko in ondemand/conservative govs
ondemand and conservative governors are messing up time units in the
code path where NO_HZ is not enabled and ignore_nice is set. The walltime
idletime stored is in jiffies and nice time calculation is happening in
microseconds.

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

The patch below fixes this thinko.

Reported-by: Alexander Miller <Miller@fmi.uni-stuttgart.de>
Tested-by: Alexander Miller <Miller@fmi.uni-stuttgart.de>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
2009-11-17 23:15:04 -05:00
Tejun Heo
384be2b18a Merge branch 'percpu-for-linus' into percpu-for-next
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>
2009-08-14 14:45:31 +09:00
Pallipadi, Venkatesh
26d204afa1 [CPUFREQ] Fix NULL pointer dereference regression in conservative governor
Commit ee88415caf
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>
2009-08-04 14:32:10 -04:00
venkatesh.pallipadi@intel.com
ee88415caf [CPUFREQ] Cleanup locking in conservative governor
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 21:38:28 -04:00
venkatesh.pallipadi@intel.com
7d26e2d5e2 [CPUFREQ] Eliminate the recent lockdep warnings in cpufreq
Commit b14893a62c 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>
2009-07-06 21:38:27 -04:00
Tejun Heo
245b2e70ea percpu: clean up percpu variable definitions
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>
2009-06-24 15:13:48 +09:00
Thomas Renninger
4f4d1ad6ee [CPUFREQ] Only set sampling_rate_max deprecated, sampling_rate_min is useful
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 11:49:41 -04:00
Thomas Renninger
cef9615a85 [CPUFREQ] ondemand: Uncouple minimal sampling rate from HZ in NO_HZ case
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>
2009-06-15 11:49:41 -04:00
Mathieu Desnoyers
b253d2b2d2 [CPUFREQ] fix timer teardown in conservative governor
* 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 12:04:50 -04:00
Alexander Clouter
a75603a084 [CPUFREQ] conservative: remove 10x from def_sampling_rate
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 22:47:32 -05:00
Alexander Clouter
8e677ce83b [CPUFREQ] conservative: fixup governor to function more like ondemand logic
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 22:47:32 -05:00
Alexander Clouter
f407a08bb7 [CPUFREQ] conservative: fix dbs_cpufreq_notifier so freq is not locked
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 22:47:32 -05:00
Alexander Clouter
11a80a9c76 [CPUFREQ] conservative: amend author's email address
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 22:47:31 -05:00
Thomas Renninger
112124ab0a [CPUFREQ] ondemand/conservative: sanitize sampling_rate restrictions
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 22:47:31 -05:00
Thomas Renninger
9411b4ef7f [CPUFREQ] ondemand/conservative: deprecate sampling_rate{min,max}
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 22:47:31 -05:00
Dave Jones
9acef48756 [CPUFREQ] checkpatch cleanups for conservative governor
Signed-off-by: Dave Jones <davej@redhat.com>
2009-02-24 22:47:29 -05:00
Rusty Russell
835481d9bc cpumask: convert struct cpufreq_policy to cpumask_var_t
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>
2009-01-06 09:05:31 +01:00
Sven Wegener
c4d14bc0bb [CPUFREQ] Don't export governors for default governor
We don't need to export the governors for use as the default governor,
because the default governor will be built-in anyway and we can access
the symbol directly.

This also fixes the following sparse warnings:

drivers/cpufreq/cpufreq_conservative.c:578:25: warning: symbol 'cpufreq_gov_conservative' was not declared. Should it be static?
drivers/cpufreq/cpufreq_ondemand.c:582:25: warning: symbol 'cpufreq_gov_ondemand' was not declared. Should it be static?
drivers/cpufreq/cpufreq_performance.c:39:25: warning: symbol 'cpufreq_gov_performance' was not declared. Should it be static?
drivers/cpufreq/cpufreq_powersave.c:38:25: warning: symbol 'cpufreq_gov_powersave' was not declared. Should it be static?
drivers/cpufreq/cpufreq_userspace.c:190:25: warning: symbol 'cpufreq_gov_userspace' was not declared. Should it be static?

Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Signed-off-by: Dave Jones <davej@redhat.com>
2008-10-09 13:52:44 -04:00
Ben Slusky
8217e4f4c9 [CPUFREQ] use deferrable delayed work init in conservative governor
Venki Pallipadi made a similar change to the ondemand governor a while
back (in commit 28287033e1). It seems to
work just as well in the conservative governor, leading to fewer wakeups
as reported by powertop.

Signed-off-by: Ben Slusky <sluskyb@paranoiacs.org>
Signed-off-by: Dave Jones <davej@redhat.com>
2008-10-09 13:52:43 -04:00
Dave Jones
f068c04ba6 [CPUFREQ] Fix -Wshadow warning in conservative governor.
drivers/cpufreq/cpufreq_conservative.c:336:15: warning: symbol 'freq_step' shadows an earlier one

Just rename the local variable.

Signed-off-by: Dave Jones <davej@redhat.com>
2008-08-08 16:00:48 -04:00
Mike Travis
068b12772a cpufreq: use performance variant for_each_cpu_mask_nr
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>
2008-05-23 18:35:12 +02:00
Johannes Weiner
6915719b36 cpufreq: Initialise default governor before use
When the cpufreq driver starts up at boot time, it calls into the default
governor which might not be initialised yet.  This hurts when the
governor's worker function relies on memory that is not yet set up by its
init function.

This migrates all governors from module_init() to fs_initcall() when being
the default, as was already done in cpufreq_performance when it was the
only possible choice.  The performance governor is always initialized early
because it might be used as fallback even when not being the default.

Fixes at least one actual oops where ondemand is the default governor and
cpufreq_governor_dbs() uses the uninitialised kondemand_wq work-queue
during boot-time.

Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-17 15:38:58 -08:00
Dave Jones
18a7247d1b [CPUFREQ] Fix up whitespace in conservative governor.
Signed-off-by: Dave Jones <davej@redhat.com>
2007-10-22 16:49:09 -04:00
Elias Oltmanns
a8d7c3bc23 [CPUFREQ] Make cpufreq_conservative handle out-of-sync events properly
Make cpufreq_conservative handle out-of-sync events properly

Currently, the cpufreq_conservative governor doesn't get notified when the
actual frequency the cpu is running at differs from what cpufreq thought it
was. As a result the cpu may stay at the maximum frequency after a s2ram /
resume cycle even though the system is idle.

Signed-off-by: Elias Oltmanns <eo@nebensachen.de>
Signed-off-by: Dave Jones <davej@redhat.com>
2007-10-22 16:34:39 -04:00
Thomas Renninger
1c2562459f [CPUFREQ] allow ondemand and conservative cpufreq governors to be used as default
Depending on the transition latency of the HW for cpufreq switches, the
ondemand or conservative governor cannot be used with certain cpufreq
drivers.  Still the ondemand should be the default governor on a wide range
of systems.  This patch allows this and lets the governor fallback to the
performance governor at cpufreq driver load time, if the driver does not
support fast enough frequency switching.

Main benefit is that on e.g.  installation or other systems without
userspace support a working dynamic cpufreq support can be achieved on most
systems by simply loading the cpufreq driver.  This is especially essential
for recent x86(_64) laptop hardware which may rely on working dynamic
cpufreq OS support.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Bryan Wu <bryan.wu@analog.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Jones <davej@redhat.com>
2007-10-04 18:40:57 -04:00