08 Dec, 2011

1 commit

  • This patch enables cpuidle for pSeries and pSeries_idle is
    directly called from the idle loop. As a result of pSeries_idle, cpuidle
    driver registered with cpuidle subsystem comes into action. On
    failure of loading of the driver or cpuidle framework default idle
    is executed as part of the function. This patch
    also removes the routines pseries_shared_idle_sleep and
    pseries_dedicated_idle_sleep as they are now implemented as part of
    pseries_idle cpuidle driver.

    Signed-off-by: Deepthi Dharwar
    Signed-off-by: Trinabh Gupta
    Signed-off-by: Arun R Bharadwaj
    Signed-off-by: Benjamin Herrenschmidt

    Deepthi Dharwar
     

08 Nov, 2011

1 commit

  • * 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
    cpuidle: Single/Global registration of idle states
    cpuidle: Split cpuidle_state structure and move per-cpu statistics fields
    cpuidle: Remove CPUIDLE_FLAG_IGNORE and dev->prepare()
    cpuidle: Move dev->last_residency update to driver enter routine; remove dev->last_state
    ACPI: Fix CONFIG_ACPI_DOCK=n compiler warning
    ACPI: Export FADT pm_profile integer value to userspace
    thermal: Prevent polling from happening during system suspend
    ACPI: Drop ACPI_NO_HARDWARE_INIT
    ACPI atomicio: Convert width in bits to bytes in __acpi_ioremap_fast()
    PNPACPI: Simplify disabled resource registration
    ACPI: Fix possible recursive locking in hwregs.c
    ACPI: use kstrdup()
    mrst pmu: update comment
    tools/power turbostat: less verbose debugging

    Linus Torvalds
     

07 Nov, 2011

4 commits

  • This patch makes the cpuidle_states structure global (single copy)
    instead of per-cpu. The statistics needed on per-cpu basis
    by the governor are kept per-cpu. This simplifies the cpuidle
    subsystem as state registration is done by single cpu only.
    Having single copy of cpuidle_states saves memory. Rare case
    of asymmetric C-states can be handled within the cpuidle driver
    and architectures such as POWER do not have asymmetric C-states.

    Having single/global registration of all the idle states,
    dynamic C-state transitions on x86 are handled by
    the boot cpu. Here, the boot cpu would disable all the devices,
    re-populate the states and later enable all the devices,
    irrespective of the cpu that would receive the notification first.

    Reference:
    https://lkml.org/lkml/2011/4/25/83

    Signed-off-by: Deepthi Dharwar
    Signed-off-by: Trinabh Gupta
    Tested-by: Jean Pihet
    Reviewed-by: Kevin Hilman
    Acked-by: Arjan van de Ven
    Acked-by: Kevin Hilman
    Signed-off-by: Len Brown

    Deepthi Dharwar
     
  • This is the first step towards global registration of cpuidle
    states. The statistics used primarily by the governor are per-cpu
    and have to be split from rest of the fields inside cpuidle_state,
    which would be made global i.e. single copy. The driver_data field
    is also per-cpu and moved.

    Signed-off-by: Deepthi Dharwar
    Signed-off-by: Trinabh Gupta
    Tested-by: Jean Pihet
    Reviewed-by: Kevin Hilman
    Acked-by: Arjan van de Ven
    Acked-by: Kevin Hilman
    Signed-off-by: Len Brown

    Deepthi Dharwar
     
  • The cpuidle_device->prepare() mechanism causes updates to the
    cpuidle_state[].flags, setting and clearing CPUIDLE_FLAG_IGNORE
    to tell the governor not to chose a state on a per-cpu basis at
    run-time. State demotion is now handled by the driver and it returns
    the actual state entered. Hence, this mechanism is not required.
    Also this removes per-cpu flags from cpuidle_state enabling
    it to be made global.

    Reference:
    https://lkml.org/lkml/2011/3/25/52

    Signed-off-by: Deepthi Dharwar
    Signed-off-by: Trinabh Gupta
    Tested-by: Jean Pihet
    Acked-by: Arjan van de Ven
    Reviewed-by: Kevin Hilman
    Signed-off-by: Len Brown

    Deepthi Dharwar
     
  • Cpuidle governor only suggests the state to enter using the
    governor->select() interface, but allows the low level driver to
    override the recommended state. The actual entered state
    may be different because of software or hardware demotion. Software
    demotion is done by the back-end cpuidle driver and can be accounted
    correctly. Current cpuidle code uses last_state field to capture the
    actual state entered and based on that updates the statistics for the
    state entered.

    Ideally the driver enter routine should update the counters,
    and it should return the state actually entered rather than the time
    spent there. The generic cpuidle code should simply handle where
    the counters live in the sysfs namespace, not updating the counters.

    Reference:
    https://lkml.org/lkml/2011/3/25/52

    Signed-off-by: Deepthi Dharwar
    Signed-off-by: Trinabh Gupta
    Tested-by: Jean Pihet
    Reviewed-by: Kevin Hilman
    Acked-by: Arjan van de Ven
    Acked-by: Kevin Hilman
    Signed-off-by: Len Brown

    Deepthi Dharwar
     

01 Nov, 2011

1 commit

  • The pretty much brings in the kitchen sink along
    with it, so it should be avoided wherever reasonably possible in
    terms of being included from other commonly used
    files, as it results in a measureable increase on compile times.

    The worst culprit was probably device.h since it is used everywhere.
    This file also had an implicit dependency/usage of mutex.h which was
    masked by module.h, and is also fixed here at the same time.

    There are over a dozen other headers that simply declare the
    struct instead of pulling in the whole file, so follow their lead
    and simply make it a few more.

    Most of the implicit dependencies on module.h being present by
    these headers pulling it in have been now weeded out, so we can
    finally make this change with hopefully minimal breakage.

    Signed-off-by: Paul Gortmaker

    Paul Gortmaker
     

04 Aug, 2011

2 commits

  • cpuidle users should call cpuidle_call_idle() directly
    rather than via (pm_idle)() function pointer.

    Architecture may choose to continue using (pm_idle)(),
    but cpuidle need not depend on it:

    my_arch_cpu_idle()
    ...
    if(cpuidle_call_idle())
    pm_idle();

    cc: Kevin Hilman
    cc: Paul Mundt
    cc: x86@kernel.org
    Acked-by: H. Peter Anvin
    Signed-off-by: Len Brown

    Len Brown
     
  • When a Xen Dom0 kernel boots on a hypervisor, it gets access
    to the raw-hardware ACPI tables. While it parses the idle tables
    for the hypervisor's beneift, it uses HLT for its own idle.

    Rather than have xen scribble on pm_idle and access default_idle,
    have it simply disable_cpuidle() so acpi_idle will not load and
    architecture default HLT will be used.

    cc: xen-devel@lists.xensource.com
    Tested-by: Konrad Rzeszutek Wilk
    Acked-by: H. Peter Anvin
    Signed-off-by: Len Brown

    Len Brown
     

13 Jan, 2011

4 commits


01 Oct, 2010

1 commit

  • Avoid TLB flush IPIs for the cores in deeper c-states by voluntary leave_mm()
    before entering into that state. CPUs tend to flush TLB in those c-states
    anyways.

    acpi_idle does this with C3-type states, but it was not caried over
    when intel_idle was introduced. intel_idle can apply it
    to C-states in addition to those that ACPI might export as C3...

    Signed-off-by: Suresh Siddha
    Signed-off-by: Len Brown

    Suresh Siddha
     

10 Aug, 2010

1 commit

  • On some SoC chips, HW resources may be in use during any particular idle
    period. As a consequence, the cpuidle states that the SoC is safe to
    enter can change from idle period to idle period. In addition, the
    latency and threshold of each cpuidle state can vary, depending on the
    operating condition when the CPU becomes idle, e.g. the current cpu
    frequency, the current state of the HW blocks, etc.

    cpuidle core and the menu governor, in the current form, are geared
    towards cpuidle states that are static, i.e. the availabiltiy of the
    states, their latencies, their thresholds are non-changing during run
    time. cpuidle does not provide any hook that cpuidle drivers can use to
    adjust those values on the fly for the current idle period before the menu
    governor selects the target cpuidle state.

    This patch extends cpuidle core and the menu governor to handle states
    that are dynamic. There are three additions in the patch and the patch
    maintains backwards-compatibility with existing cpuidle drivers.

    1) add prepare() to struct cpuidle_device. A cpuidle driver can hook
    into the callback and cpuidle will call prepare() before calling the
    governor's select function. The callback gives the cpuidle driver a
    chance to update the dynamic information of the cpuidle states for the
    current idle period, e.g. state availability, latencies, thresholds,
    power values, etc.

    2) add CPUIDLE_FLAG_IGNORE as one of the state flags. In the prepare()
    function, a cpuidle driver can set/clear the flag to indicate to the
    menu governor whether a cpuidle state should be ignored, i.e. not
    available, during the current idle period.

    3) add power_specified bit to struct cpuidle_device. The menu governor
    currently assumes that the cpuidle states are arranged in the order of
    increasing latency, threshold, and power savings. This is true or can
    be made true for static states. Once the state parameters are dynamic,
    the latencies, thresholds, and power savings for the cpuidle states can
    increase or decrease by different amounts from idle period to idle
    period. So the assumption of increasing latency, threshold, and power
    savings from Cn to C(n+1) can no longer be guaranteed.

    It can be straightforward to calculate the power consumption of each
    available state and to specify it in power_usage for the idle period.
    Using the power_usage fields, the menu governor then selects the state
    that has the lowest power consumption and that still satisfies all other
    critieria. The power_specified bit defaults to 0. For existing cpuidle
    drivers, cpuidle detects that power_specified is 0 and fills in a dummy
    set of power_usage values.

    Signed-off-by: Ai Li
    Cc: Len Brown
    Acked-by: Arjan van de Ven
    Cc: Ingo Molnar
    Cc: Venkatesh Pallipadi
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ai Li
     

28 May, 2010

1 commit

  • cpuidle_register_driver() sets cpuidle_curr_driver
    cpuidle_unregister_driver() clears cpuidle_curr_driver

    We should't expose cpuidle_curr_driver to
    potential modification except via these interfaces.
    So make it static and create cpuidle_get_driver() to observe it.

    Signed-off-by: Len Brown

    Len Brown
     

27 May, 2010

1 commit


12 Jun, 2008

1 commit

  • cpuidle and acpi driver interaction bug with the way cpuidle_register_driver()
    is called. Due to this bug, there will be oops on
    ACDC on some systems, where they support C-states in one DC and not in AC.

    The current code does
    ON BOOT:
    Look at CST and other C-state info to see whether more than C1 is
    supported. If it is, then acpi processor_idle does a
    cpuidle_register_driver() call, which internally enables the device.

    ON CST change notification (ACDC) and on suspend-resume:
    acpi driver temporarily disables device, updates the device with
    any new C-states, and reenables the device.

    The problem is is on boot, there are no C2, C3 states supported and we skip
    the register. Later on ACDC, we may get a CST notification and we try
    to reevaluate CST and enabled the device, without actually registering it.
    This causes breakage as we try to create /sys fs sub directory, without the
    parent directory which is created at register time.

    Thanks to Sanjeev for reporting the problem here.
    http://bugzilla.kernel.org/show_bug.cgi?id=10394

    Signed-off-by: Venkatesh Pallipadi
    Signed-off-by: Len Brown

    Venkatesh Pallipadi
     

26 Mar, 2008

1 commit

  • cpuidle C-state sysfs node time and usage are very easy to overflow because
    they are all of unsigned int type, time will overflow within about two hours,
    usage will take longer time to overflow, but they are increasing for ever.

    This patch will convert them to unsigned long long.

    Signed-off-by: Yi Yang
    Acked-by: Venkatesh Pallipadi
    Signed-off-by: Len Brown

    Yi Yang
     

14 Feb, 2008

1 commit

  • Add a new sysfs entry under cpuidle states. desc - can be used by driver to
    communicate to userspace any specific information about the state.
    This helps in identifying the exact hardware C-states behind the ACPI C-state
    definition.

    Idea is to export this through powertop, which will help to map the C-state
    reported by powertop to actual hardware C-state.

    Signed-off-by: Venkatesh Pallipadi
    Signed-off-by: Len Brown

    Venkatesh Pallipadi
     

07 Feb, 2008

4 commits


01 Feb, 2008

1 commit

  • Convert cpu_idle_wait() to cpuidle_kick_cpus() macro which is
    SMP-only, and gives error on non supported CPU.

    Signed-off-by: Kevin Hilman
    Acked-by: Venkatesh Pallipadi
    Acked-by: Rafael J. Wysocki
    Signed-off-by: Len Brown

    Kevin Hilman
     

20 Nov, 2007

1 commit

  • Fix for http://bugzilla.kernel.org/show_bug.cgi?id=9355

    cpuidle always used to fallback to C2 if there is some bm activity while
    entering C3. But, presence of C2 is not always guaranteed. Change cpuidle
    algorithm to detect a safe_state to fallback in case of bm_activity and
    use that state instead of C2.

    Signed-off-by: Venkatesh Pallipadi
    Signed-off-by: Len Brown

    Venkatesh Pallipadi
     

10 Oct, 2007

1 commit

  • commit e5a16b1f9eec0af7cfa0830304b41c1c0833cf9f
    Author: Len Brown
    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: Len Brown

    commit dfbb9d5aedfb18848a3e0d6f6e3e4969febb209c
    Author: Len Brown
    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: Len Brown

    commit 889172fc915f5a7fe20f35b133cbd205ce69bf6c
    Author: Venki Pallipadi
    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: Venkatesh Pallipadi
    Signed-off-by: Len Brown

    commit 9544a8181edc7ecc33b3bfd69271571f98ed08bc
    Author: Venki Pallipadi
    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: Venkatesh Pallipadi
    Signed-off-by: Len Brown

    commit 8975059a2c1e56cfe83d1bcf031bcf4cb39be743
    Author: Adam Belay
    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: Adam Belay
    Acked-by: Venkatesh Pallipadi
    Signed-off-by: Len Brown

    commit e0322e2b58dd1b12ec669bf84693efe0dc2414a8
    Author: Adam Belay
    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: Adam Belay
    Acked-by: Venkatesh Pallipadi
    Signed-off-by: Len Brown

    commit 18a6e770d5c82ba26653e53d240caa617e09e9ab
    Author: Adam Belay
    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: Adam Belay
    Acked-by: Venkatesh Pallipadi
    Signed-off-by: Len Brown

    commit 1fdc0887286179b40ce24bcdbde663172e205ef0
    Author: Adam Belay
    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: Adam Belay
    Acked-by: Venkatesh Pallipadi
    Signed-off-by: Len Brown

    commit 0ef38840db666f48e3cdd2b769da676c57228dd9
    Author: Adam Belay
    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: Adam Belay
    Acked-by: Venkatesh Pallipadi
    Signed-off-by: Len Brown

    commit bb4d74fca63fa96cf3ace644b15ae0f12b7df5a1
    Author: Adam Belay
    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: Adam Belay
    Acked-by: Venkatesh Pallipadi
    Signed-off-by: Len Brown

    commit df3c71559bb69b125f1a48971bf0d17f78bbdf47
    Author: Len Brown
    Date: Sun Aug 12 02:00:45 2007 -0400

    cpuidle: fix IA64 build (again)

    Signed-off-by: Len Brown

    commit a02064579e3f9530fd31baae16b1fc46b5a7bca8
    Author: Venkatesh Pallipadi
    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: Venkatesh Pallipadi
    Signed-off-by: Len Brown

    commit 0912a44b13adf22f5e3f607d263aed23b4910d7e
    Author: Venkatesh Pallipadi
    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: Venkatesh Pallipadi
    Signed-off-by: Len Brown

    commit c649a76e76be6bff1fd770d0a775798813a3f6e0
    Author: Venkatesh Pallipadi
    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: Venkatesh Pallipadi
    Acked-by: Adam Belay
    Signed-off-by: Len Brown

    commit 2305a5920fb8ee6ccec1c62ade05aa8351091d71
    Author: Adam Belay
    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: Adam Belay
    Acked-by: Venkatesh Pallipadi
    Acked-by: Shaohua Li
    Signed-off-by: Len Brown

    commit df25b6b56955714e6e24b574d88d1fd11f0c3ee5
    Author: Len Brown
    Date: Tue Jul 24 17:08:21 2007 -0400

    cpuidle: fix IA64 buid

    Signed-off-by: Len Brown

    commit fd6ada4c14488755ff7068860078c437431fbccd
    Author: Adrian Bunk
    Date: Mon Jul 9 11:33:13 2007 -0700

    cpuidle: static

    make cpuidle_replace_governor() static

    Signed-off-by: Adrian Bunk
    Cc: Venkatesh Pallipadi
    Signed-off-by: Andrew Morton
    Signed-off-by: Len Brown

    commit c1d4a2cebcadf2429c0c72e1d29aa2a9684c32e0
    Author: Adrian Bunk
    Date: Tue Jul 3 00:54:40 2007 -0400

    cpuidle: static

    This patch makes the needlessly global struct menu_governor static.

    Signed-off-by: Adrian Bunk
    Signed-off-by: Andrew Morton
    Signed-off-by: Len Brown

    commit dbf8780c6e8d572c2c273da97ed1cca7608fd999
    Author: Andrew Morton
    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
    Cc: Venki Pallipadi
    Cc: Ingo Molnar
    Cc: Thomas Gleixner
    Cc: john stultz
    Signed-off-by: Andrew Morton
    Signed-off-by: Len Brown

    commit 29f0e248e7017be15f99febf9143a2cef00b2961
    Author: Andrew Morton
    Date: Tue Jul 3 00:43:04 2007 -0400

    tick.h needs hrtimer.h

    It uses hrtimers.

    Signed-off-by: Andrew Morton
    Signed-off-by: Len Brown

    commit e40cede7d63a029e92712a3fe02faee60cc38fb4
    Author: Venki Pallipadi
    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: Venkatesh Pallipadi
    Signed-off-by: Andrew Morton
    Signed-off-by: Len Brown

    commit 83b42be2efece386976507555c29e7773a0dfcd1
    Author: Venki Pallipadi
    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: Venkatesh Pallipadi
    Signed-off-by: Andrew Morton
    Signed-off-by: Len Brown

    commit d2a74b8c5e8f22def4709330d4bfc4a29209b71c
    Author: Venki Pallipadi
    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: Venkatesh Pallipadi
    Signed-off-by: Andrew Morton
    Signed-off-by: Len Brown

    commit 1f60a0e80bf83cf6b55c8845bbe5596ed8f6307b
    Author: Venki Pallipadi
    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: Venkatesh Pallipadi
    Signed-off-by: Andrew Morton
    Signed-off-by: Len Brown

    commit 45a42095cf64b003b4a69be3ce7f434f97d7af51
    Author: Venki Pallipadi
    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: Venkatesh Pallipadi
    Signed-off-by: Andrew Morton
    Signed-off-by: Len Brown

    commit 80dca7cdba3e6ee13eae277660873ab9584eb3be
    Author: Venki Pallipadi
    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: Venkatesh Pallipadi
    Signed-off-by: Andrew Morton
    Signed-off-by: Len Brown

    commit 589c37c2646c5e3813a51255a5ee1159cb4c33fc
    Author: Venki Pallipadi
    Date: Tue Jul 3 00:32:37 2007 -0400

    cpuidle: menu governor and hrtimer compile fix

    Compile fix for menu governor.

    Signed-off-by: Venkatesh Pallipadi
    Signed-off-by: Andrew Morton
    Signed-off-by: Len Brown

    commit 0ba80bd9ab3ed304cb4f19b722e4cc6740588b5e
    Author: Len Brown
    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: Len Brown

    commit d7d8fa7f96a7f7682be7c6cc0cc53fa7a18c3b58
    Author: Adam Belay
    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: Adam Belay
    Signed-off-by: Len Brown

    commit a4bec7e65aa3b7488b879d971651cc99a6c410fe
    Author: Adam Belay
    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: Adam Belay
    Signed-off-by: Len Brown

    commit 2929d8996fbc77f41a5ff86bb67cdde3ca7d2d72
    Author: Adam Belay
    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: Adam Belay
    Signed-off-by: Len Brown

    commit 3a7fd42f9825c3b03e364ca59baa751bb350775f
    Author: Venki Pallipadi
    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: Venkatesh Pallipadi
    Signed-off-by: Andrew Morton
    Signed-off-by: Len Brown

    commit 4893339a142afbd5b7c01ffadfd53d14746e858e
    Author: Shaohua Li
    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: Shaohua Li
    Signed-off-by: Len Brown

    commit 43bbbbe1cb998cbd2df656f55bb3bfe30f30e7d1
    Author: Shaohua Li
    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: Shaohua Li
    Signed-off-by: Len Brown

    commit d1edadd608f24836def5ec483d2edccfb37b1d19
    Author: Shaohua Li
    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: Shaohua Li
    Signed-off-by: Len Brown

    commit 7169a5cc0d67b263978859672e86c13c23a5570d
    Author: Randy Dunlap
    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: Randy Dunlap
    Cc: Venkatesh Pallipadi
    Signed-off-by: Andrew Morton
    Signed-off-by: Len Brown

    commit 4658620158dc2fbd9e4bcb213c5b6fb5d05ba7d4
    Author: Venkatesh Pallipadi
    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.html

    Signed-off-by: Venkatesh Pallipadi
    Cc: Larry Finger
    Signed-off-by: Andrew Morton
    Signed-off-by: Len Brown

    commit c17e168aa6e5fe3851baaae8df2fbc1cf11443a9
    Author: Len Brown
    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: Len Brown

    commit 8c91d958246bde68db0c3f0c57b535962ce861cb
    Author: Adrian Bunk
    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: Adrian Bunk
    Cc: Venkatesh Pallipadi
    Cc: Adam Belay
    Cc: Shaohua Li
    Signed-off-by: Andrew Morton
    Signed-off-by: Len Brown

    commit 0c39dc3187094c72c33ab65a64d2017b21f372d2
    Author: Venkatesh Pallipadi
    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: Venkatesh Pallipadi
    Signed-off-by: Adrian Bunk
    Signed-off-by: Andrew Morton
    Signed-off-by: Len Brown

    commit 8112e3b115659b07df340ef170515799c0105f82
    Author: Venkatesh Pallipadi
    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: Venkatesh Pallipadi
    Cc: Adam Belay
    Cc: Shaohua Li
    Signed-off-by: Andrew Morton
    Signed-off-by: Len Brown

    commit 1eb4431e9599cd25e0d9872f3c2c8986821839dd
    Author: Venkatesh Pallipadi
    Date: Thu Feb 22 13:54:57 2007 -0800

    cpuidle take2: Basic documentation for cpuidle

    Documentation for cpuidle infrastructure

    Signed-off-by: Venkatesh Pallipadi
    Signed-off-by: Adam Belay
    Signed-off-by: Shaohua Li
    Signed-off-by: Len Brown

    commit ef5f15a8b79123a047285ec2e3899108661df779
    Author: Venkatesh Pallipadi
    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: Shaohua Li
    Signed-off-by: Venkatesh Pallipadi
    Signed-off-by: Adam Belay
    Signed-off-by: Len Brown

    commit 987196fa82d4db52c407e8c9d5dec884ba602183
    Author: Venkatesh Pallipadi
    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: Adam Belay
    Signed-off-by: Shaohua Li
    Signed-off-by: Venkatesh Pallipadi
    Signed-off-by: Len Brown

    Signed-off-by: Len Brown

    Len Brown