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* [CPUFREQ] CPUfreq ondemand: update sampling rate without waiting for next ↵MyungJoo Ham2012-02-291-1/+57
| | | | | | | | | | | | | | | | | | | | | | 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>
* Merge branch 'next' of ↵Linus Torvalds2012-01-111-2/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * [CPUFREQ] Remove wall variable from cpufreq_gov_dbs_init()Kamalesh Babulal2011-12-091-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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(-)
* | Merge branch 'sched/core' of ↵Martin Schwidefsky2011-12-191-21/+20
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * | sched/accounting: Change cpustat fields to an arrayGlauber Costa2011-12-061-20/+18
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | [S390] cputime: add sparse checking and cleanupMartin Schwidefsky2011-12-151-17/+16
|/ | | | | | | | 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>
* Merge branch 'timers-core-for-linus' of ↵Linus Torvalds2011-10-261-1/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * nohz: Fix update_ts_time_stat idle accountingMichal Hocko2011-09-081-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | Fix documentation and comment typo 'no_hz'Paul Bolle2011-08-081-1/+1
|/ | | | | | Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Acked-by: Len Brown <len.brown@intel.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* [CPUFREQ] Remove unneeded locksThomas Renninger2011-03-161-24/+1
| | | | | | | | | | | | | 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
* [CPUFREQ] Remove old, deprecated per cpu ondemand/conservative sysfs filesThomas Renninger2011-03-161-67/+0
| | | | | | | | 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
* [CPUFREQ] Remove deprecated sysfs file sampling_rate_maxThomas Renninger2011-03-161-13/+0
| | | | | | | | 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
* [CPUFREQ] calculate delay after dbs_check_cpuVincent Guittot2011-03-161-6/+11
| | | | | | | | | | 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>
* cpufreq: use system_wq instead of dedicated workqueuesTejun Heo2011-01-261-17/+3
| | | | | | | | | | | | 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
* [CPUFREQ] add sampling_down_factor tunable to improve ondemand performanceDavid C Niemi2010-10-221-1/+41
| | | | | | | | | | | | | | | | | | | | | | 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>
* [CPUFREQ] ondemand: don't synchronize sample rate unless multiple cpus presentJocelyn Falempe2010-08-031-2/+6
| | | | | | | | | | | 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>
* [CPUFREQ] ondemand: Refactor frequency increase codeMike Chan2010-08-031-13/+12
| | | | | | | | | | 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>
* Merge branch 'x86-cpu-for-linus' of ↵Linus Torvalds2010-05-181-29/+13
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * cpufreq: Unify sysfs attribute definition macrosBorislav Petkov2010-04-091-28/+12
| | | | | | | | | | | | | | | | | | | | | | 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>
* | ondemand: Make the iowait-is-busy time a sysfs tunableArjan van de Ven2010-05-091-1/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | ondemand: Solve a big performance issue by counting IOWAIT time as busyArjan van de Ven2010-05-091-2/+28
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [CPUFREQ] Fix ondemand to not request targets outside policy limitsNagananda.Chumbalkar@hp.com2010-01-131-0/+3
| | | | | | | | | | | | | | | | | | 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
* [CPUFREQ] Resolve time unit thinko in ondemand/conservative govsPallipadi, Venkatesh2009-11-171-2/+2
| | | | | | | | | | | | | | | | | 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>
* Merge branch 'next' of ↵Linus Torvalds2009-09-181-26/+113
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * [CPUFREQ] ondemand - Use global sysfs dir for tuning settingsThomas Renninger2009-09-011-26/+113
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | Merge branch 'percpu-for-linus' into percpu-for-nextTejun Heo2009-08-141-45/+32
|\ \ | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * [CPUFREQ] Cleanup locking in ondemand governorvenkatesh.pallipadi@intel.com2009-07-061-35/+27
| | | | | | | | | | | | | | | | | | 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>
| * [CPUFREQ] Eliminate the recent lockdep warnings in cpufreqvenkatesh.pallipadi@intel.com2009-07-061-16/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | percpu: clean up percpu variable definitionsTejun Heo2009-06-241-7/+8
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [CPUFREQ] Only set sampling_rate_max deprecated, sampling_rate_min is usefulThomas Renninger2009-06-151-16/+2
| | | | | | | | 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>
* [CPUFREQ] ondemand: Uncouple minimal sampling rate from HZ in NO_HZ caseThomas Renninger2009-06-151-27/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [CPUFREQ] fix timer teardown in ondemand governorMathieu Desnoyers2009-05-261-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 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>
* [CPUFREQ] ondemand/conservative: sanitize sampling_rate restrictionsThomas Renninger2009-02-241-10/+18
| | | | | | | | 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>
* [CPUFREQ] ondemand/conservative: deprecate sampling_rate{min,max}Thomas Renninger2009-02-241-0/+17
| | | | | | | 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>
* [CPUFREQ] checkpatch cleanups for ondemand governor.Dave Jones2009-02-241-16/+13
| | | | Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] Make ignore_nice_load setting of ondemand work as expected.Venkatesh Pallipadi2009-02-051-22/+25
| | | | | | | | | | | | | 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>
* cpumask: convert struct cpufreq_policy to cpumask_var_tRusty Russell2009-01-061-2/+2
| | | | | | | | | | | | | | 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>
* [CPUFREQ] Fix BUG: using smp_processor_id() in preemptible codeAndrea Righi2008-10-091-1/+4
| | | | | | | | | | | | | | | | | | | | Use get_cpu()/put_cpu() in cpufreq_ondemand init routine, instead of smp_processor_id() to avoid the following BUG: [ 35.313118] BUG: using smp_processor_id() in preemptible [00000000] code=: modprobe/4952 [ 35.313132] caller is cpufreq_gov_dbs_init+0xa/0x8f [cpufreq_ondemand] [ 35.313140] Pid: 4952, comm: modprobe Not tainted 2.6.27-rc5-mm1 #23 [ 35.313145] Call Trace: [ 35.313158] [<ffffffff80361ff7>] debug_smp_processor_id+0xd7/0xe0 [ 35.313167] [<ffffffffa010800a>] cpufreq_gov_dbs_init+0xa/0x8f [cpufreq_ondemand] [ 35.313176] [<ffffffff8020903b>] _stext+0x3b/0x160 [ 35.313185] [<ffffffff804768c5>] __mutex_unlock_slowpath+0xe5/0x190 [ 35.313195] [<ffffffff8026236a>] trace_hardirqs_on_caller+0xca/0x140 [ 35.313205] [<ffffffff8026ef4c>] sys_init_module+0xdc/0x210 [ 35.313212] [<ffffffff8020b7cb>] system_call_fastpath+0x16/0x1b Signed-off-by: Andrea Righi <righi.andrea@gmail.com> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] Don't export governors for default governorSven Wegener2008-10-091-1/+3
| | | | | | | | | | | | | | | | | 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>
* [CPUFREQ][6/6] cpufreq: Add idle microaccounting in ondemand governorvenkatesh.pallipadi@intel.com2008-10-091-1/+44
| | | | | | | | | | | | Use get_cpu_idle_time_us() to get micro-accounted idle information. This enables ondemand to get more accurate idle and busy timings than the jiffy based calculation. As a result, we can decrease the ondemand safety gaurd band from 80-10 to 95-3. Results in more aggressive power savings. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ][4/6] cpufreq_ondemand: Parameterize down differentialvenkatesh.pallipadi@intel.com2008-10-091-2/+9
| | | | | | | | | Use a parameter for down differential, instead of hardcoded 10%. Follow-on patch changes the down-differential dynamically, based on whether we are using idle micro-accounting or not. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ][3/6] cpufreq: get_cpu_idle_time() changes in ondemand for ↵venkatesh.pallipadi@intel.com2008-10-091-14/+15
| | | | | | | | | | | idle-microaccounting Preparatory changes for doing idle micro-accounting in ondemand governor. get_cpu_idle_time() gets extra parameter and returns idle time and also the wall time that corresponds to the idle time measurement. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ][2/6] cpufreq: Change load calculation in ondemand for software ↵venkatesh.pallipadi@intel.com2008-10-091-30/+35
| | | | | | | | | | | | | | | coordination Change the load calculation algorithm in ondemand to work well with software coordination of frequency across the dependent cpus. Multiply individual CPU utilization with the average freq of that logical CPU during the measurement interval (using getavg call). And find the max CPU utilization number in terms of CPU freq. That number is then used to get to the target freq for next sampling interval. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ][1/6] cpufreq: Add cpu number parameter to __cpufreq_driver_getavg()venkatesh.pallipadi@intel.com2008-10-091-1/+1
| | | | | | | | | | | | | | | Add a cpu parameter to __cpufreq_driver_getavg(). This is needed for software cpufreq coordination where policy->cpu may not be same as the CPU on which we want to getavg frequency. A follow-on patch will use this parameter to getavg freq from all cpus in policy->cpus. Change since last patch. Fix the offline/online and suspend/resume oops reported by Youquan Song <youquan.song@intel.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] add error handling for cpufreq_register_governor() errorAkinobu Mita2008-10-091-1/+7
| | | | | | | | Add error handling for cpufreq_register_governor() error Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: cpufreq@lists.linux.org.uk Signed-off-by: Dave Jones <davej@redhat.com>
* cpufreq: use performance variant for_each_cpu_mask_nrMike Travis2008-05-231-2/+2
| | | | | | | | | | | | 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>
* cpufreq: Initialise default governor before useJohannes Weiner2008-01-171-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [CPUFREQ] allow ondemand and conservative cpufreq governors to be used as ↵Thomas Renninger2007-10-041-13/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [CPUFREQ] ondemand: fix tickless accounting and software coordination bugVenki Pallipadi2007-06-211-7/+18
| | | | | | | | | | | | | | | | | | | With tickless kernel and software coordination os P-states, ondemand can look at wrong idle statistics. This can happen when ondemand sampling is happening on CPU 0 and due to software coordination sampling also looks at utilization of CPU 1. If CPU 1 is in tickless state at that moment, its idle statistics will not be uptodate and CPU 0 thinks CPU 1 is idle for less amount of time than it actually is. This can be resolved by looking at all the busy times of CPUs, which is accurate, even with tickless, and use that to determine idle time in a round about way (total time - busy time). Thanks to Arjan for originally reporting the ondemand bug on Lenovo T61. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
* [CPUFREQ] ondemand: add a check to avoid negative load calculationVenki Pallipadi2007-06-211-2/+3
| | | | | | | | | Due to rounding and inexact jiffy accounting, idle_ticks can sometimes be higher than total_ticks. Make sure those cases are handled as zero load case. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
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