1. 22 Sep, 2009 2 commits
    • Corrado Zoccolo's avatar
      cpuidle: menu governor: reduce latency on exit · 672917dc
      Corrado Zoccolo authored
      Move the state residency accounting and statistics computation off the hot
      exit path.
      
      On exit, the need to recompute statistics is recorded, and new statistics
      will be computed when menu_select is called again.
      
      The expected effect is to reduce processor wakeup latency from sleep
      (C-states).  We are speaking of few hundreds of cycles reduction out of a
      several microseconds latency (determined by the hardware transition), so
      it is difficult to measure.
      Signed-off-by: default avatarCorrado Zoccolo <czoccolo@gmail.com>
      Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Cc: Len Brown <len.brown@intel.com>
      Cc: Adam Belay <abelay@novell.com
      Acked-by: default avatarArjan van de Ven <arjan@linux.intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      672917dc
    • Arjan van de Ven's avatar
      cpuidle: fix the menu governor to boost IO performance · 69d25870
      Arjan van de Ven authored
      Fix the menu idle governor which balances power savings, energy efficiency
      and performance impact.
      
      The reason for a reworked governor is that there have been serious
      performance issues reported with the existing code on Nehalem server
      systems.
      
      To show this I'm sure Andrew wants to see benchmark results:
      (benchmark is "fio", "no cstates" is using "idle=poll")
      
      		no cstates	current linux	new algorithm
      1 disk		107 Mb/s	85 Mb/s		105 Mb/s
      2 disks		215 Mb/s	123 Mb/s	209 Mb/s
      12 disks	590 Mb/s	320 Mb/s	585 Mb/s
      
      In various power benchmark measurements, no degredation was found by our
      measurement&diagnostics team.  Obviously a small percentage more power was
      used in the "fio" benchmark, due to the much higher performance.
      
      While it would be a novel idea to describe the new algorithm in this
      commit message, I cheaped out and described it in comments in the code
      instead.
      
      [changes since first post: spelling fixes from akpm, review feedback,
      folded menu-tng into menu.c]
      Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
      Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Cc: Len Brown <lenb@kernel.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com>
      Acked-by: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      69d25870
  2. 30 Dec, 2008 1 commit
  3. 15 Aug, 2008 2 commits
  4. 05 Feb, 2008 1 commit
    • Mark Gross's avatar
      pm qos infrastructure and interface · d82b3518
      Mark Gross authored
      The following patch is a generalization of the latency.c implementation done
      by Arjan last year.  It provides infrastructure for more than one parameter,
      and exposes a user mode interface for processes to register pm_qos
      expectations of processes.
      
      This interface provides a kernel and user mode interface for registering
      performance expectations by drivers, subsystems and user space applications on
      one of the parameters.
      
      Currently we have {cpu_dma_latency, network_latency, network_throughput} as
      the initial set of pm_qos parameters.
      
      The infrastructure exposes multiple misc device nodes one per implemented
      parameter.  The set of parameters implement is defined by pm_qos_power_init()
      and pm_qos_params.h.  This is done because having the available parameters
      being runtime configurable or changeable from a driver was seen as too easy to
      abuse.
      
      For each parameter a list of performance requirements is maintained along with
      an aggregated target value.  The aggregated target value is updated with
      changes to the requirement list or elements of the list.  Typically the
      aggregated target value is simply the max or min of the requirement values
      held in the parameter list elements.
      
      >From kernel mode the use of this interface is simple:
      
      pm_qos_add_requirement(param_id, name, target_value):
      
        Will insert a named element in the list for that identified PM_QOS
        parameter with the target value.  Upon change to this list the new target is
        recomputed and any registered notifiers are called only if the target value
        is now different.
      
      pm_qos_update_requirement(param_id, name, new_target_value):
      
        Will search the list identified by the param_id for the named list element
        and then update its target value, calling the notification tree if the
        aggregated target is changed.  with that name is already registered.
      
      pm_qos_remove_requirement(param_id, name):
      
        Will search the identified list for the named element and remove it, after
        removal it will update the aggregate target and call the notification tree
        if the target was changed as a result of removing the named requirement.
      
      >From user mode:
      
        Only processes can register a pm_qos requirement.  To provide for
        automatic cleanup for process the interface requires the process to register
        its parameter requirements in the following way:
      
        To register the default pm_qos target for the specific parameter, the
        process must open one of /dev/[cpu_dma_latency, network_latency,
        network_throughput]
      
        As long as the device node is held open that process has a registered
        requirement on the parameter.  The name of the requirement is
        "process_<PID>" derived from the current->pid from within the open system
        call.
      
        To change the requested target value the process needs to write a s32
        value to the open device node.  This translates to a
        pm_qos_update_requirement call.
      
        To remove the user mode request for a target value simply close the device
        node.
      
      [akpm@linux-foundation.org: fix warnings]
      [akpm@linux-foundation.org: fix build]
      [akpm@linux-foundation.org: fix build again]
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: default avatarmark gross <mgross@linux.intel.com>
      Cc: "John W. Linville" <linville@tuxdriver.com>
      Cc: Len Brown <lenb@kernel.org>
      Cc: Jaroslav Kysela <perex@suse.cz>
      Cc: Takashi Iwai <tiwai@suse.de>
      Cc: Arjan van de Ven <arjan@infradead.org>
      Cc: Venki Pallipadi <venkatesh.pallipadi@intel.com>
      Cc: Adam Belay <abelay@novell.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d82b3518
  5. 09 Oct, 2007 1 commit
    • Len Brown's avatar
      cpuidle: consolidate 2.6.22 cpuidle branch into one patch · 4f86d3a8
      Len Brown authored
      commit e5a16b1f9eec0af7cfa0830304b41c1c0833cf9f
      Author: Len Brown <len.brown@intel.com>
      Date:   Tue Oct 2 23:44:44 2007 -0400
      
          cpuidle: shrink diff
      
          processor_idle.c |  440 +++++++++++++++++++++++++++++++++++++++++--
          1 file changed, 429 insertions(+), 11 deletions(-)
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit dfbb9d5aedfb18848a3e0d6f6e3e4969febb209c
      Author: Len Brown <len.brown@intel.com>
      Date:   Wed Sep 26 02:17:55 2007 -0400
      
          cpuidle: reduce diff size
      
          Reduces the cpuidle processor_idle.c diff vs 2.6.22 from this
           processor_idle.c | 2006 ++++++++++++++++++++++++++-----------------
           1 file changed, 1219 insertions(+), 787 deletions(-)
      
          to this:
           processor_idle.c |  502 +++++++++++++++++++++++++++++++++++++++----
           1 file changed, 458 insertions(+), 44 deletions(-)
      
          ...for the purpose of making the cpuilde patch less invasive
          and easier to review.
      
          no functional changes.  build tested only.
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 889172fc915f5a7fe20f35b133cbd205ce69bf6c
      Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
      Date:   Thu Sep 13 13:40:05 2007 -0700
      
          cpuidle: Retain old ACPI policy for !CONFIG_CPU_IDLE
      
          Retain the old policy in processor_idle, so that when CPU_IDLE is not
          configured, old C-state policy will still be used. This provides a
          clean gradual migration path from old ACPI policy to new cpuidle
          based policy.
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 9544a8181edc7ecc33b3bfd69271571f98ed08bc
      Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
      Date:   Thu Sep 13 13:39:17 2007 -0700
      
          cpuidle: Configure governors by default
      
          Quoting Len "Do not give an option to users to shoot themselves in the foot".
      
          Remove the configurability of ladder and menu governors as they are
          needed for default policy of cpuidle. That way users will not be able to
          have cpuidle without any policy loosing all C-state power savings.
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 8975059a2c1e56cfe83d1bcf031bcf4cb39be743
      Author: Adam Belay <abelay@novell.com>
      Date:   Tue Aug 21 18:27:07 2007 -0400
      
          CPUIDLE: load ACPI properly when CPUIDLE is disabled
      
          Change the registration return codes for when CPUIDLE
          support is not compiled into the kernel.  As a result, the ACPI
          processor driver will load properly even if CPUIDLE is unavailable.
          However, it may be possible to cleanup the ACPI processor driver further
          and eliminate some dead code paths.
      Signed-off-by: default avatarAdam Belay <abelay@novell.com>
      Acked-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit e0322e2b58dd1b12ec669bf84693efe0dc2414a8
      Author: Adam Belay <abelay@novell.com>
      Date:   Tue Aug 21 18:26:06 2007 -0400
      
          CPUIDLE: remove cpuidle_get_bm_activity()
      
          Remove cpuidle_get_bm_activity() and updates governors
          accordingly.
      Signed-off-by: default avatarAdam Belay <abelay@novell.com>
      Acked-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 18a6e770d5c82ba26653e53d240caa617e09e9ab
      Author: Adam Belay <abelay@novell.com>
      Date:   Tue Aug 21 18:25:58 2007 -0400
      
          CPUIDLE: max_cstate fix
      
          Currently max_cstate is limited to 0, resulting in no idle processor
          power management on ACPI platforms.  This patch restores the value to
          the array size.
      Signed-off-by: default avatarAdam Belay <abelay@novell.com>
      Acked-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 1fdc0887286179b40ce24bcdbde663172e205ef0
      Author: Adam Belay <abelay@novell.com>
      Date:   Tue Aug 21 18:25:40 2007 -0400
      
          CPUIDLE: handle BM detection inside the ACPI Processor driver
      
          Update the ACPI processor driver to detect BM activity and
          limit state entry depth internally, rather than exposing such
          requirements to CPUIDLE.  As a result, CPUIDLE can drop this
          ACPI-specific interface and become more platform independent.  BM
          activity is now handled much more aggressively than it was in the
          original implementation, so some testing coverage may be needed to
          verify that this doesn't introduce any DMA buffer under-run issues.
      Signed-off-by: default avatarAdam Belay <abelay@novell.com>
      Acked-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 0ef38840db666f48e3cdd2b769da676c57228dd9
      Author: Adam Belay <abelay@novell.com>
      Date:   Tue Aug 21 18:25:14 2007 -0400
      
          CPUIDLE: menu governor updates
      
          Tweak the menu governor to more effectively handle non-timer
          break events.  Non-timer break events are detected by comparing the
          actual sleep time to the expected sleep time.  In future revisions, it
          may be more reliable to use the timer data structures directly.
      Signed-off-by: default avatarAdam Belay <abelay@novell.com>
      Acked-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit bb4d74fca63fa96cf3ace644b15ae0f12b7df5a1
      Author: Adam Belay <abelay@novell.com>
      Date:   Tue Aug 21 18:24:40 2007 -0400
      
          CPUIDLE: fix 'current_governor' sysfs entry
      
          Allow the "current_governor" sysfs entry to properly handle
          input terminated with '\n'.
      Signed-off-by: default avatarAdam Belay <abelay@novell.com>
      Acked-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit df3c71559bb69b125f1a48971bf0d17f78bbdf47
      Author: Len Brown <len.brown@intel.com>
      Date:   Sun Aug 12 02:00:45 2007 -0400
      
          cpuidle: fix IA64 build (again)
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit a02064579e3f9530fd31baae16b1fc46b5a7bca8
      Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Date:   Sun Aug 12 01:39:27 2007 -0400
      
          cpuidle: Remove support for runtime changing of max_cstate
      
          Remove support for runtime changeability of max_cstate. Drivers can use
          use latency APIs.
      
          max_cstate can still be used as a boot time option and dmi override.
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 0912a44b13adf22f5e3f607d263aed23b4910d7e
      Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Date:   Sun Aug 12 01:39:16 2007 -0400
      
          cpuidle: Remove ACPI cstate_limit calls from ipw2100
      
          ipw2100 already has code to use accetable_latency interfaces to limit the
          C-state. Remove the calls to acpi_set_cstate_limit and acpi_get_cstate_limit
          as they are redundant.
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit c649a76e76be6bff1fd770d0a775798813a3f6e0
      Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Date:   Sun Aug 12 01:35:39 2007 -0400
      
          cpuidle: compile fix for pause and resume functions
      
          Fix the compilation failure when cpuidle is not compiled in.
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Acked-by: default avatarAdam Belay <adam.belay@novell.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 2305a5920fb8ee6ccec1c62ade05aa8351091d71
      Author: Adam Belay <abelay@novell.com>
      Date:   Thu Jul 19 00:49:00 2007 -0400
      
          cpuidle: re-write
      
          Some portions have been rewritten to make the code cleaner and lighter
          weight.  The following is a list of changes:
      
          1.) the state name is now included in the sysfs interface
          2.) detection, hotplug, and available state modifications are handled by
          CPUIDLE drivers directly
          3.) the CPUIDLE idle handler is only ever installed when at least one
          cpuidle_device is enabled and ready
          4.) the menu governor BM code no longer overflows
          5.) the sysfs attributes are now printed as unsigned integers, avoiding
          negative values
          6.) a variety of other small cleanups
      
          Also, Idle drivers are no longer swappable during runtime through the
          CPUIDLE sysfs inteface.  On i386 and x86_64 most idle handlers (e.g.
          poll, mwait, halt, etc.) don't benefit from an infrastructure that
          supports multiple states, so I think using a more general case idle
          handler selection mechanism would be cleaner.
      Signed-off-by: default avatarAdam Belay <abelay@novell.com>
      Acked-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Acked-by: default avatarShaohua Li <shaohua.li@intel.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit df25b6b56955714e6e24b574d88d1fd11f0c3ee5
      Author: Len Brown <len.brown@intel.com>
      Date:   Tue Jul 24 17:08:21 2007 -0400
      
          cpuidle: fix IA64 buid
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit fd6ada4c14488755ff7068860078c437431fbccd
      Author: Adrian Bunk <bunk@stusta.de>
      Date:   Mon Jul 9 11:33:13 2007 -0700
      
          cpuidle: static
      
          make cpuidle_replace_governor() static
      Signed-off-by: default avatarAdrian Bunk <bunk@stusta.de>
          Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit c1d4a2cebcadf2429c0c72e1d29aa2a9684c32e0
      Author: Adrian Bunk <bunk@stusta.de>
      Date:   Tue Jul 3 00:54:40 2007 -0400
      
          cpuidle: static
      
          This patch makes the needlessly global struct menu_governor static.
      Signed-off-by: default avatarAdrian Bunk <bunk@stusta.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit dbf8780c6e8d572c2c273da97ed1cca7608fd999
      Author: Andrew Morton <akpm@linux-foundation.org>
      Date:   Tue Jul 3 00:49:14 2007 -0400
      
          export symbol tick_nohz_get_sleep_length
      
          ERROR: "tick_nohz_get_sleep_length" [drivers/cpuidle/governors/menu.ko] undefined!
          ERROR: "tick_nohz_get_idle_jiffies" [drivers/cpuidle/governors/menu.ko] undefined!
      
          And please be sure to get your changes to core kernel suitably reviewed.
      
          Cc: Adam Belay <abelay@novell.com>
          Cc: Venki Pallipadi <venkatesh.pallipadi@intel.com>
          Cc: Ingo Molnar <mingo@elte.hu>
          Cc: Thomas Gleixner <tglx@linutronix.de>
          Cc: john stultz <johnstul@us.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 29f0e248e7017be15f99febf9143a2cef00b2961
      Author: Andrew Morton <akpm@linux-foundation.org>
      Date:   Tue Jul 3 00:43:04 2007 -0400
      
          tick.h needs hrtimer.h
      
          It uses hrtimers.
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit e40cede7d63a029e92712a3fe02faee60cc38fb4
      Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
      Date:   Tue Jul 3 00:40:34 2007 -0400
      
          cpuidle: first round of documentation updates
      
          Documentation changes based on Pavel's feedback.
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 83b42be2efece386976507555c29e7773a0dfcd1
      Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
      Date:   Tue Jul 3 00:39:25 2007 -0400
      
          cpuidle: add rating to the governors and pick the one with highest rating by default
      
          Introduce a governor rating scheme to pick the right governor by default.
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit d2a74b8c5e8f22def4709330d4bfc4a29209b71c
      Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
      Date:   Tue Jul 3 00:38:08 2007 -0400
      
          cpuidle: make cpuidle sysfs driver governor switch off by default
      
          Make default cpuidle sysfs to show current_governor and current_driver in
          read-only mode.  More elaborate available_governors and available_drivers with
          writeable current_governor and current_driver interface only appear with
          "cpuidle_sysfs_switch" boot parameter.
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 1f60a0e80bf83cf6b55c8845bbe5596ed8f6307b
      Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
      Date:   Tue Jul 3 00:37:00 2007 -0400
      
          cpuidle: menu governor: change the early break condition
      
          Change the C-state early break out algorithm in menu governor.
      
          We only look at early breakouts that result in wakeups shorter than idle
          state's target_residency.  If such a breakout is frequent enough, eliminate
          the particular idle state upto a timeout period.
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 45a42095cf64b003b4a69be3ce7f434f97d7af51
      Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
      Date:   Tue Jul 3 00:35:38 2007 -0400
      
          cpuidle: fix uninitialized variable in sysfs routine
      
          Fix the uninitialized usage of ret.
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 80dca7cdba3e6ee13eae277660873ab9584eb3be
      Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
      Date:   Tue Jul 3 00:34:16 2007 -0400
      
          cpuidle: reenable /proc/acpi//power interface for the time being
      
          Keep /proc/acpi/processor/CPU*/power around for a while as powertop depends
          on it. It will be marked deprecated and removed in future. powertop can use
          cpuidle interfaces instead.
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 589c37c2646c5e3813a51255a5ee1159cb4c33fc
      Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
      Date:   Tue Jul 3 00:32:37 2007 -0400
      
          cpuidle: menu governor and hrtimer compile fix
      
          Compile fix for menu governor.
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 0ba80bd9ab3ed304cb4f19b722e4cc6740588b5e
      Author: Len Brown <len.brown@intel.com>
      Date:   Thu May 31 22:51:43 2007 -0400
      
          cpuidle: build fix - cpuidle vs ipw2100 module
      
          ERROR: "acpi_set_cstate_limit" [drivers/net/wireless/ipw2100.ko] undefined!
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit d7d8fa7f96a7f7682be7c6cc0cc53fa7a18c3b58
      Author: Adam Belay <abelay@novell.com>
      Date:   Sat Mar 24 03:47:07 2007 -0400
      
          cpuidle: add the 'menu' governor
      
          Here is my first take at implementing an idle PM governor that takes
          full advantage of NO_HZ.  I call it the 'menu' governor because it
          considers the full list of idle states before each entry.
      
          I've kept the implementation fairly simple.  It attempts to guess the
          next residency time and then chooses a state that would meet at least
          the break-even point between power savings and entry cost.  To this end,
          it selects the deepest idle state that satisfies the following
          constraints:
               1. If the idle time elapsed since bus master activity was detected
                  is below a threshold (currently 20 ms), then limit the selection
                  to C2-type or above.
               2. Do not choose a state with a break-even residency that exceeds
                  the expected time remaining until the next timer interrupt.
               3. Do not choose a state with a break-even residency that exceeds
                  the elapsed time between the last pair of break events,
                  excluding timer interrupts.
      
          This governor has an advantage over "ladder" governor because it
          proactively checks how much time remains until the next timer interrupt
          using the tick infrastructure.  Also, it handles device interrupt
          activity more intelligently by not including timer interrupts in break
          event calculations.  Finally, it doesn't make policy decisions using the
          number of state entries, which can have variable residency times (NO_HZ
          makes these potentially very large), and instead only considers sleep
          time deltas.
      
          The menu governor can be selected during runtime using the cpuidle sysfs
          interface like so:
          "echo "menu" > /sys/devices/system/cpu/cpuidle/current_governor"
      Signed-off-by: default avatarAdam Belay <abelay@novell.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit a4bec7e65aa3b7488b879d971651cc99a6c410fe
      Author: Adam Belay <abelay@novell.com>
      Date:   Sat Mar 24 03:47:03 2007 -0400
      
          cpuidle: export time until next timer interrupt using NO_HZ
      
          Expose information about the time remaining until the next
          timer interrupt expires by utilizing the dynticks infrastructure.
          Also modify the main idle loop to allow dynticks to handle
          non-interrupt break events (e.g. DMA).  Finally, expose sleep ticks
          information to external code.  Thomas Gleixner is responsible for much
          of the code in this patch.  However, I've made some additional changes,
          so I'm probably responsible if there are any bugs or oversights :)
      Signed-off-by: default avatarAdam Belay <abelay@novell.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 2929d8996fbc77f41a5ff86bb67cdde3ca7d2d72
      Author: Adam Belay <abelay@novell.com>
      Date:   Sat Mar 24 03:46:58 2007 -0400
      
          cpuidle: governor API changes
      
          This patch prepares cpuidle for the menu governor.  It adds an optional
          stage after idle state entry to give the governor an opportunity to
          check why the state was exited.  Also it makes sure the idle loop
          returns after each state entry, allowing the appropriate dynticks code
          to run.
      Signed-off-by: default avatarAdam Belay <abelay@novell.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 3a7fd42f9825c3b03e364ca59baa751bb350775f
      Author: Venki Pallipadi <venkatesh.pallipadi@intel.com>
      Date:   Thu Apr 26 00:03:59 2007 -0700
      
          cpuidle: hang fix
      
          Prevent hang on x86-64, when ACPI processor driver is added as a module on
          a system that does not support C-states.
      
          x86-64 expects all idle handlers to enable interrupts before returning from
          idle handler.  This is due to enter_idle(), exit_idle() races.  Make
          cpuidle_idle_call() confirm to this when there is no pm_idle_old.
      
          Also, cpuidle look at the return values of attch_driver() and set
          current_driver to NULL if attach fails on all CPUs.
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 4893339a142afbd5b7c01ffadfd53d14746e858e
      Author: Shaohua Li <shaohua.li@intel.com>
      Date:   Thu Apr 26 10:40:09 2007 +0800
      
          cpuidle: add support for max_cstate limit
      
          With CPUIDLE framework, the max_cstate (to limit max cpu c-state)
          parameter is ingored. Some systems require it to ignore C2/C3
          and some drivers like ipw require it too.
      Signed-off-by: default avatarShaohua Li <shaohua.li@intel.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 43bbbbe1cb998cbd2df656f55bb3bfe30f30e7d1
      Author: Shaohua Li <shaohua.li@intel.com>
      Date:   Thu Apr 26 10:40:13 2007 +0800
      
          cpuidle: add cpuidle_fore_redetect_devices API
      
          add cpuidle_force_redetect_devices API,
          which forces all CPU redetect idle states.
          Next patch will use it.
      Signed-off-by: default avatarShaohua Li <shaohua.li@intel.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit d1edadd608f24836def5ec483d2edccfb37b1d19
      Author: Shaohua Li <shaohua.li@intel.com>
      Date:   Thu Apr 26 10:40:01 2007 +0800
      
          cpuidle: fix sysfs related issue
      
          Fix the cpuidle sysfs issue.
          a. make kobject dynamicaly allocated
          b. fixed sysfs init issue to avoid suspend/resume issue
      Signed-off-by: default avatarShaohua Li <shaohua.li@intel.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 7169a5cc0d67b263978859672e86c13c23a5570d
      Author: Randy Dunlap <randy.dunlap@oracle.com>
      Date:   Wed Mar 28 22:52:53 2007 -0400
      
          cpuidle: 1-bit field must be unsigned
      
          A 1-bit bitfield has no room for a sign bit.
          drivers/cpuidle/governors/ladder.c:54:16: error: dubious bitfield without explicit `signed' or `unsigned'
      Signed-off-by: default avatarRandy Dunlap <randy.dunlap@oracle.com>
          Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 4658620158dc2fbd9e4bcb213c5b6fb5d05ba7d4
      Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Date:   Wed Mar 28 22:52:41 2007 -0400
      
          cpuidle: fix boot hang
      
          Patch for cpuidle boot hang reported by Larry Finger here.
          http://www.ussg.iu.edu/hypermail/linux/kernel/0703.2/2025.htmlSigned-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
          Cc: Larry Finger <larry.finger@lwfinger.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit c17e168aa6e5fe3851baaae8df2fbc1cf11443a9
      Author: Len Brown <len.brown@intel.com>
      Date:   Wed Mar 7 04:37:53 2007 -0500
      
          cpuidle: ladder does not depend on ACPI
      
          build fix for CONFIG_ACPI=n
      
          In file included from drivers/cpuidle/governors/ladder.c:21:
          include/acpi/processor.h:88: error: expected specifier-qualifier-list before ‘acpi_integer’
          include/acpi/processor.h:106: error: expected specifier-qualifier-list before ‘acpi_integer’
          include/acpi/processor.h:168: error: expected specifier-qualifier-list before ‘acpi_handle’
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 8c91d958246bde68db0c3f0c57b535962ce861cb
      Author: Adrian Bunk <bunk@stusta.de>
      Date:   Tue Mar 6 02:29:40 2007 -0800
      
          cpuidle: make code static
      
          This patch makes the following needlessly global code static:
          - driver.c: __cpuidle_find_driver()
          - governor.c: __cpuidle_find_governor()
          - ladder.c: struct ladder_governor
      Signed-off-by: default avatarAdrian Bunk <bunk@stusta.de>
          Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
          Cc: Adam Belay <abelay@novell.com>
          Cc: Shaohua Li <shaohua.li@intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 0c39dc3187094c72c33ab65a64d2017b21f372d2
      Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Date:   Wed Mar 7 02:38:22 2007 -0500
      
          cpu_idle: fix build break
      
          This patch fixes a build breakage with !CONFIG_HOTPLUG_CPU and
          CONFIG_CPU_IDLE.
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarAdrian Bunk <bunk@stusta.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 8112e3b115659b07df340ef170515799c0105f82
      Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Date:   Tue Mar 6 02:29:39 2007 -0800
      
          cpuidle: build fix for !CPU_IDLE
      
          Fix the compile issues when CPU_IDLE is not configured.
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
          Cc: Adam Belay <abelay@novell.com>
          Cc: Shaohua Li <shaohua.li@intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 1eb4431e9599cd25e0d9872f3c2c8986821839dd
      Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Date:   Thu Feb 22 13:54:57 2007 -0800
      
          cpuidle take2: Basic documentation for cpuidle
      
          Documentation for cpuidle infrastructure
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarAdam Belay <abelay@novell.com>
      Signed-off-by: default avatarShaohua Li <shaohua.li@intel.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit ef5f15a8b79123a047285ec2e3899108661df779
      Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Date:   Thu Feb 22 13:54:03 2007 -0800
      
          cpuidle take2: Hookup ACPI C-states driver with cpuidle
      
          Hookup ACPI C-states onto generic cpuidle infrastructure.
      
          drivers/acpi/procesor_idle.c is now a ACPI C-states driver that registers as
          a driver in cpuidle infrastructure and the policy part is removed from
          drivers/acpi/processor_idle.c. We use governor in cpuidle instead.
      Signed-off-by: default avatarShaohua Li <shaohua.li@intel.com>
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarAdam Belay <abelay@novell.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      
      commit 987196fa82d4db52c407e8c9d5dec884ba602183
      Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Date:   Thu Feb 22 13:52:57 2007 -0800
      
          cpuidle take2: Core cpuidle infrastructure
      
          Announcing 'cpuidle', a new CPU power management infrastructure to manage
          idle CPUs in a clean and efficient manner.
          cpuidle separates out the drivers that can provide support for multiple types
          of idle states and policy governors that decide on what idle state to use
          at run time.
          A cpuidle driver can support multiple idle states based on parameters like
          varying power consumption, wakeup latency, etc (ACPI C-states for example).
          A cpuidle governor can be usage model specific (laptop, server,
          laptop on battery etc).
          Main advantage of the infrastructure being, it allows independent development
          of drivers and governors and allows for better CPU power management.
      
          A huge thanks to Adam Belay and Shaohua Li who were part of this mini-project
          since its beginning and are greatly responsible for this patchset.
      
          This patch:
      
          Core cpuidle infrastructure.
          Introduces a new abstraction layer for cpuidle:
          * which manages drivers that can support multiple idles states. Drivers
            can be generic or particular to specific hardware/platform
          * allows pluging in multiple policy governors that can take idle state policy
            decision
          * The core also has a set of sysfs interfaces with which administrato can know
            about supported drivers and governors and switch them at run time.
      Signed-off-by: default avatarAdam Belay <abelay@novell.com>
      Signed-off-by: default avatarShaohua Li <shaohua.li@intel.com>
      Signed-off-by: default avatarVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      4f86d3a8