linux.git/kernel/sched/idle.c, branch v3.17 Linux kernel source tree Merge tag 'pm+acpi-3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm 2014-08-07T03:34:19+00:00 Linus Torvalds torvalds@linux-foundation.org 2014-08-07T03:34:19+00:00 7725131982477bffff8ffdea143434dcc69f5d90 Pull ACPI and power management updates from Rafael Wysocki: "Again, ACPICA leads the pack (47 commits), followed by cpufreq (18 commits) and system suspend/hibernation (9 commits). From the new code perspective, the ACPICA update brings ACPI 5.1 to the table, including a new device configuration object called _DSD (Device Specific Data) that will hopefully help us to operate device properties like Device Trees do (at least to some extent) and changes related to supporting ACPI on ARM. Apart from that we have hibernation changes making it use radix trees to store memory bitmaps which should speed up some operations carried out by it quite significantly. We also have some power management changes related to suspend-to-idle (the "freeze" sleep state) support and more preliminary changes needed to support ACPI on ARM (outside of ACPICA). The rest is fixes and cleanups pretty much everywhere. Specifics: - ACPICA update to upstream version 20140724. That includes ACPI 5.1 material (support for the _CCA and _DSD predefined names, changes related to the DMAR and PCCT tables and ARM support among other things) and cleanups related to using ACPICA's header files. A major part of it is related to acpidump and the core code used by that utility. Changes from Bob Moore, David E Box, Lv Zheng, Sascha Wildner, Tomasz Nowicki, Hanjun Guo. - Radix trees for memory bitmaps used by the hibernation core from Joerg Roedel. - Support for waking up the system from suspend-to-idle (also known as the "freeze" sleep state) using ACPI-based PCI wakeup signaling (Rafael J Wysocki). - Fixes for issues related to ACPI button events (Rafael J Wysocki). - New device ID for an ACPI-enumerated device included into the Wildcat Point PCH from Jie Yang. - ACPI video updates related to backlight handling from Hans de Goede and Linus Torvalds. - Preliminary changes needed to support ACPI on ARM from Hanjun Guo and Graeme Gregory. - ACPI PNP core cleanups from Arjun Sreedharan and Zhang Rui. - Cleanups related to ACPI_COMPANION() and ACPI_HANDLE() macros (Rafael J Wysocki). - ACPI-based device hotplug cleanups from Wei Yongjun and Rafael J Wysocki. - Cleanups and improvements related to system suspend from Lan Tianyu, Randy Dunlap and Rafael J Wysocki. - ACPI battery cleanup from Wei Yongjun. - cpufreq core fixes from Viresh Kumar. - Elimination of a deadband effect from the cpufreq ondemand governor and intel_pstate driver cleanups from Stratos Karafotis. - 350MHz CPU support for the powernow-k6 cpufreq driver from Mikulas Patocka. - Fix for the imx6 cpufreq driver from Anson Huang. - cpuidle core and governor cleanups from Daniel Lezcano, Sandeep Tripathy and Mohammad Merajul Islam Molla. - Build fix for the big_little cpuidle driver from Sachin Kamat. - Configuration fix for the Operation Performance Points (OPP) framework from Mark Brown. - APM cleanup from Jean Delvare. - cpupower utility fixes and cleanups from Peter Senna Tschudin, Andrey Utkin, Himangi Saraogi, Rickard Strandqvist, Thomas Renninger" * tag 'pm+acpi-3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (118 commits) ACPI / LPSS: add LPSS device for Wildcat Point PCH ACPI / PNP: Replace faulty is_hex_digit() by isxdigit() ACPICA: Update version to 20140724. ACPICA: ACPI 5.1: Update for PCCT table changes. ACPICA/ARM: ACPI 5.1: Update for GTDT table changes. ACPICA/ARM: ACPI 5.1: Update for MADT changes. ACPICA/ARM: ACPI 5.1: Update for FADT changes. ACPICA: ACPI 5.1: Support for the _CCA predifined name. ACPICA: ACPI 5.1: New notify value for System Affinity Update. ACPICA: ACPI 5.1: Support for the _DSD predefined name. ACPICA: Debug object: Add current value of Timer() to debug line prefix. ACPICA: acpihelp: Add UUID support, restructure some existing files. ACPICA: Utilities: Fix local printf issue. ACPICA: Tables: Update for DMAR table changes. ACPICA: Remove some extraneous printf arguments. ACPICA: Update for comments/formatting. No functional changes. ACPICA: Disassembler: Add support for the ToUUID opererator (macro). ACPICA: Remove a redundant cast to acpi_size for ACPI_OFFSET() macro. ACPICA: Work around an ancient GCC bug. ACPI / processor: Make it possible to get local x2apic id via _MAT ... 
Pull ACPI and power management updates from Rafael Wysocki:
 "Again, ACPICA leads the pack (47 commits), followed by cpufreq (18
  commits) and system suspend/hibernation (9 commits).

  From the new code perspective, the ACPICA update brings ACPI 5.1 to
  the table, including a new device configuration object called _DSD
  (Device Specific Data) that will hopefully help us to operate device
  properties like Device Trees do (at least to some extent) and changes
  related to supporting ACPI on ARM.

  Apart from that we have hibernation changes making it use radix trees
  to store memory bitmaps which should speed up some operations carried
  out by it quite significantly.  We also have some power management
  changes related to suspend-to-idle (the "freeze" sleep state) support
  and more preliminary changes needed to support ACPI on ARM (outside of
  ACPICA).

  The rest is fixes and cleanups pretty much everywhere.

  Specifics:

   - ACPICA update to upstream version 20140724.  That includes ACPI 5.1
     material (support for the _CCA and _DSD predefined names, changes
     related to the DMAR and PCCT tables and ARM support among other
     things) and cleanups related to using ACPICA's header files.  A
     major part of it is related to acpidump and the core code used by
     that utility.  Changes from Bob Moore, David E Box, Lv Zheng,
     Sascha Wildner, Tomasz Nowicki, Hanjun Guo.

   - Radix trees for memory bitmaps used by the hibernation core from
     Joerg Roedel.

   - Support for waking up the system from suspend-to-idle (also known
     as the "freeze" sleep state) using ACPI-based PCI wakeup signaling
     (Rafael J Wysocki).

   - Fixes for issues related to ACPI button events (Rafael J Wysocki).

   - New device ID for an ACPI-enumerated device included into the
     Wildcat Point PCH from Jie Yang.

   - ACPI video updates related to backlight handling from Hans de Goede
     and Linus Torvalds.

   - Preliminary changes needed to support ACPI on ARM from Hanjun Guo
     and Graeme Gregory.

   - ACPI PNP core cleanups from Arjun Sreedharan and Zhang Rui.

   - Cleanups related to ACPI_COMPANION() and ACPI_HANDLE() macros
     (Rafael J Wysocki).

   - ACPI-based device hotplug cleanups from Wei Yongjun and Rafael J
     Wysocki.

   - Cleanups and improvements related to system suspend from Lan
     Tianyu, Randy Dunlap and Rafael J Wysocki.

   - ACPI battery cleanup from Wei Yongjun.

   - cpufreq core fixes from Viresh Kumar.

   - Elimination of a deadband effect from the cpufreq ondemand governor
     and intel_pstate driver cleanups from Stratos Karafotis.

   - 350MHz CPU support for the powernow-k6 cpufreq driver from Mikulas
     Patocka.

   - Fix for the imx6 cpufreq driver from Anson Huang.

   - cpuidle core and governor cleanups from Daniel Lezcano, Sandeep
     Tripathy and Mohammad Merajul Islam Molla.

   - Build fix for the big_little cpuidle driver from Sachin Kamat.

   - Configuration fix for the Operation Performance Points (OPP)
     framework from Mark Brown.

   - APM cleanup from Jean Delvare.

   - cpupower utility fixes and cleanups from Peter Senna Tschudin,
     Andrey Utkin, Himangi Saraogi, Rickard Strandqvist, Thomas
     Renninger"

* tag 'pm+acpi-3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (118 commits)
  ACPI / LPSS: add LPSS device for Wildcat Point PCH
  ACPI / PNP: Replace faulty is_hex_digit() by isxdigit()
  ACPICA: Update version to 20140724.
  ACPICA: ACPI 5.1: Update for PCCT table changes.
  ACPICA/ARM: ACPI 5.1: Update for GTDT table changes.
  ACPICA/ARM: ACPI 5.1: Update for MADT changes.
  ACPICA/ARM: ACPI 5.1: Update for FADT changes.
  ACPICA: ACPI 5.1: Support for the _CCA predifined name.
  ACPICA: ACPI 5.1: New notify value for System Affinity Update.
  ACPICA: ACPI 5.1: Support for the _DSD predefined name.
  ACPICA: Debug object: Add current value of Timer() to debug line prefix.
  ACPICA: acpihelp: Add UUID support, restructure some existing files.
  ACPICA: Utilities: Fix local printf issue.
  ACPICA: Tables: Update for DMAR table changes.
  ACPICA: Remove some extraneous printf arguments.
  ACPICA: Update for comments/formatting. No functional changes.
  ACPICA: Disassembler: Add support for the ToUUID opererator (macro).
  ACPICA: Remove a redundant cast to acpi_size for ACPI_OFFSET() macro.
  ACPICA: Work around an ancient GCC bug.
  ACPI / processor: Make it possible to get local x2apic id via _MAT
  ...
cpuidle: move idle traces to cpuidle_enter_state() 2014-07-09T13:45:23+00:00 Sandeep Tripathy sandeep.tripathy@linaro.org 2014-07-02T09:30:58+00:00 30fe6884021b9fa0124609e898a6341be188eb44 idle_exit event is the first event after a core exits idle state. So this should be traced before local irq is ebabled. Likewise idle_entry is the last event before a core enters idle state. This will ease visualising the cpu idle state from kernel traces. Signed-off-by: Sandeep Tripathy <sandeep.tripathy@linaro.org> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> [rjw: Subject, rebase] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
idle_exit event is the first event after a core exits
idle state. So this should be traced before local irq
is ebabled. Likewise idle_entry is the last event before
a core enters idle state. This will ease visualising the
cpu idle state from kernel traces.

Signed-off-by: Sandeep Tripathy <sandeep.tripathy@linaro.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
[rjw: Subject, rebase]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
sched/idle: Drop !! while calculating 'broadcast' 2014-07-05T09:17:31+00:00 Viresh Kumar viresh.kumar@linaro.org 2014-06-24T04:31:01+00:00 89abb5ad10ae8ac3405e635ac80815f781c8b8e9 We don't need 'broadcast' to be set to 'zero or one', but to 'zero or non-zero' and so the extra operation to convert it to 'zero or one' can be skipped. Also change type of 'broadcast' to unsigned int, i.e. type of drv->states[*].flags. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: linaro-kernel@lists.linaro.org Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/0dfbe2976aa108c53e08d3477ea90f6360c1f54c.1403584026.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org> 
We don't need 'broadcast' to be set to 'zero or one', but to 'zero or non-zero'
and so the extra operation to convert it to 'zero or one' can be skipped.

Also change type of 'broadcast' to unsigned int, i.e. type of
drv->states[*].flags.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linaro-kernel@lists.linaro.org
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/0dfbe2976aa108c53e08d3477ea90f6360c1f54c.1403584026.git.viresh.kumar@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched/idle: Optimize try-to-wake-up IPI 2014-06-05T10:09:53+00:00 Peter Zijlstra peterz@infradead.org 2014-06-04T17:31:18+00:00 e3baac47f0e82c4be632f4f97215bb93bf16b342 [ This series reduces the number of IPIs on Andy's workload by something like 99%. It's down from many hundreds per second to very few. The basic idea behind this series is to make TIF_POLLING_NRFLAG be a reliable indication that the idle task is polling. Once that's done, the rest is reasonably straightforward. ] When enqueueing tasks on remote LLC domains, we send an IPI to do the work 'locally' and avoid bouncing all the cachelines over. However, when the remote CPU is idle (and polling, say x86 mwait), we don't need to send an IPI, we can simply kick the TIF word to wake it up and have the 'idle' loop do the work. So when _TIF_POLLING_NRFLAG is set, but _TIF_NEED_RESCHED is not (yet) set, set _TIF_NEED_RESCHED and avoid sending the IPI. Much-requested-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Peter Zijlstra <peterz@infradead.org> [Edited by Andy Lutomirski, but this is mostly Peter Zijlstra's code.] Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: nicolas.pitre@linaro.org Cc: daniel.lezcano@linaro.org Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: umgwanakikbuti@gmail.com Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/ce06f8b02e7e337be63e97597fc4b248d3aa6f9b.1401902905.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org> 
[ This series reduces the number of IPIs on Andy's workload by something like
  99%. It's down from many hundreds per second to very few.

  The basic idea behind this series is to make TIF_POLLING_NRFLAG be a
  reliable indication that the idle task is polling.  Once that's done,
  the rest is reasonably straightforward. ]

When enqueueing tasks on remote LLC domains, we send an IPI to do the
work 'locally' and avoid bouncing all the cachelines over.

However, when the remote CPU is idle (and polling, say x86 mwait), we
don't need to send an IPI, we can simply kick the TIF word to wake it
up and have the 'idle' loop do the work.

So when _TIF_POLLING_NRFLAG is set, but _TIF_NEED_RESCHED is not (yet)
set, set _TIF_NEED_RESCHED and avoid sending the IPI.

Much-requested-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
[Edited by Andy Lutomirski, but this is mostly Peter Zijlstra's code.]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: nicolas.pitre@linaro.org
Cc: daniel.lezcano@linaro.org
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: umgwanakikbuti@gmail.com
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/ce06f8b02e7e337be63e97597fc4b248d3aa6f9b.1401902905.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched/idle: Clear polling before descheduling the idle thread 2014-06-05T10:09:51+00:00 Andy Lutomirski luto@amacapital.net 2014-06-04T17:31:16+00:00 82c65d60d64401aedc1006d6572469bbfdf148de Currently, the only real guarantee provided by the polling bit is that, if you hold rq->lock and the polling bit is set, then you can set need_resched to force a reschedule. The only reason the lock is needed is that the idle thread might not be running at all when setting its need_resched bit, and rq->lock keeps it pinned. This is easy to fix: just clear the polling bit before scheduling. Now the idle thread's polling bit is only ever set when rq->curr == rq->idle. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: nicolas.pitre@linaro.org Cc: daniel.lezcano@linaro.org Cc: umgwanakikbuti@gmail.com Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/b2059fcb4c613d520cb503b6fad6e47033c7c203.1401902905.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org> 
Currently, the only real guarantee provided by the polling bit is
that, if you hold rq->lock and the polling bit is set, then you can
set need_resched to force a reschedule.

The only reason the lock is needed is that the idle thread might not
be running at all when setting its need_resched bit, and rq->lock
keeps it pinned.

This is easy to fix: just clear the polling bit before scheduling.
Now the idle thread's polling bit is only ever set when
rq->curr == rq->idle.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: nicolas.pitre@linaro.org
Cc: daniel.lezcano@linaro.org
Cc: umgwanakikbuti@gmail.com
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/b2059fcb4c613d520cb503b6fad6e47033c7c203.1401902905.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Merge branch 'pm-cpuidle' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm into sched/core 2014-05-22T08:37:06+00:00 Ingo Molnar mingo@kernel.org 2014-05-22T08:37:06+00:00 ec6e7f4082aa0c6c4334149e74673b6ed736fb63 Pull scheduling related CPU idle updates from Rafael J. Wysocki. Conflicts: kernel/sched/idle.c Signed-off-by: Ingo Molnar <mingo@kernel.org> 
Pull scheduling related CPU idle updates from Rafael J. Wysocki.

Conflicts:
	kernel/sched/idle.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched/idle: Make cpuidle_idle_call() void 2014-05-08T07:17:00+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2014-04-20T23:26:58+00:00 08c373e5123b4595588ae1a7aa7e00a046c61cc6 The only value ever returned by cpuidle_idle_call() is 0 and its only caller ignores that value anyway, so make it void. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/4717784.WmVEpDoliM@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org> 
The only value ever returned by cpuidle_idle_call() is 0 and its
only caller ignores that value anyway, so make it void.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/4717784.WmVEpDoliM@vostro.rjw.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched/idle: Reflow cpuidle_idle_call() 2014-05-08T07:16:59+00:00 Peter Zijlstra peterz@infradead.org 2014-04-11T11:55:48+00:00 37352273ad48f2d177ed1b06ced32d5536b773fb Apply goto to reduce lines and nesting levels. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-cc6vb0snt3sr7op6rlbfeqfh@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> 
Apply goto to reduce lines and nesting levels.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-cc6vb0snt3sr7op6rlbfeqfh@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched/idle: Delay clearing the polling bit 2014-05-08T07:16:58+00:00 Peter Zijlstra peterz@infradead.org 2014-04-11T11:47:16+00:00 c444117f0f39d59733ec23da67c44424df529230 With the generic idle functions assuming !polling we should only clear the polling bit at the very last opportunity in order to avoid spurious IPIs. Ideally we'd flip the default to polling, but that means auditing all arch idle functions. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-vq7719foqzf6z5h4j7eh7f9e@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> 
With the generic idle functions assuming !polling we should only clear
the polling bit at the very last opportunity in order to avoid
spurious IPIs.

Ideally we'd flip the default to polling, but that means auditing all
arch idle functions.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-vq7719foqzf6z5h4j7eh7f9e@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
cpuidle: Combine cpuidle_enabled() with cpuidle_select() 2014-04-30T22:13:47+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2014-04-30T22:13:47+00:00 52c324f8a87b336496d0f5e9d8dff1aa32bb08cd Since both cpuidle_enabled() and cpuidle_select() are only called by cpuidle_idle_call(), it is not really useful to keep them separate and combining them will help to avoid complicating cpuidle_idle_call() even further if governors are changed to return error codes sometimes. This code modification shouldn't lead to any functional changes. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Since both cpuidle_enabled() and cpuidle_select() are only called by
cpuidle_idle_call(), it is not really useful to keep them separate
and combining them will help to avoid complicating cpuidle_idle_call()
even further if governors are changed to return error codes sometimes.

This code modification shouldn't lead to any functional changes.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>