Eric Lee / smarc-ti-linux-kernel

10 Oct, 2008

1 commit

29 Sep, 2008

1 commit

  • ccc7dadf7   hrtimer: prevent migration of per CPU hrtimers ... Browse Code »

    Impact: per CPU hrtimers can be migrated from a dead CPU

    The hrtimer code has no knowledge about per CPU timers, but we need to
    prevent the migration of such timers and warn when such a timer is
    active at migration time.

    Explicitely mark the timers as per CPU and use a more understandable
    mode descriptor for the interrupts safe unlocked callback mode, which
    is used by hrtimer_sleeper and the scheduler code.

    Signed-off-by: Thomas Gleixner

    Thomas Gleixner
     

23 Sep, 2008

2 commits

  • 49d670fb8   clockevents: prevent stale tick_next_period for onlining CPUs ... Browse Code »

    Impact: possible hang on CPU onlining in timer one shot mode.

    The tick_next_period variable is only used during boot on nohz/highres
    enabled systems, but for CPU onlining it needs to be maintained when
    the per cpu clock events device operates in one shot mode.

    Signed-off-by: Thomas Gleixner

    Thomas Gleixner
     
  • 6441402b1   clockevents: prevent cpu online to interfere with nohz ... Browse Code »

    Impact: rare hang which can be triggered on CPU online.

    tick_do_timer_cpu keeps track of the CPU which updates jiffies
    via do_timer. The value -1 is used to signal, that currently no
    CPU is doing this. There are two cases, where the variable can
    have this state:

    boot:
    necessary for systems where the boot cpu id can be != 0

    nohz long idle sleep:
    When the CPU which did the jiffies update last goes into
    a long idle sleep it drops the update jiffies duty so
    another CPU which is not idle can pick it up and keep
    jiffies going.

    Using the same value for both situations is wrong, as the CPU online
    code can see the -1 state when the timer of the newly onlined CPU is
    setup. The setup for a newly onlined CPU goes through periodic mode
    and can pick up the do_timer duty without being aware of the nohz /
    highres mode of the already running system.

    Use two separate states and make them constants to avoid magic
    numbers confusion.

    Signed-off-by: Thomas Gleixner

    Thomas Gleixner
     

06 Sep, 2008

1 commit

  • 56c7426b3   sched_clock: fix NOHZ interaction ... Browse Code »

    If HLT stops the TSC, we'll fail to account idle time, thereby inflating the
    actual process times. Fix this by re-calibrating the clock against GTOD when
    leaving nohz mode.

    Signed-off-by: Peter Zijlstra
    Tested-by: Avi Kivity
    Signed-off-by: Ingo Molnar

    Peter Zijlstra
     

21 Aug, 2008

1 commit

  • 3c4fbe5e0   nohz: fix wrong event handler after online an offlined cpu ... Browse Code »

    On the tickless system(CONFIG_NO_HZ=y and CONFIG_HIGH_RES_TIMERS=n), after
    I made an offlined cpu online, I found this cpu's event handler was
    tick_handle_periodic, not tick_nohz_handler.

    After debuging, I found this bug was caused by the wrong tick mode. the
    tick mode is not changed to NOHZ_MODE_INACTIVE when the cpu is offline.

    This patch fixes this bug.

    Signed-off-by: Miao Xie
    Signed-off-by: Andrew Morton
    Signed-off-by: Ingo Molnar

    Miao Xie
     

31 Jul, 2008

1 commit

  • e4e4e534f   sched clock: revert various sched_clock() changes ... Browse Code »

    Found an interactivity problem on a quad core test-system - simple
    CPU loops would occasionally delay the system un an unacceptable way.

    After much debugging with Peter Zijlstra it turned out that the problem
    is caused by the string of sched_clock() changes - they caused the CPU
    clock to jump backwards a bit - which confuses the scheduler arithmetics.

    (which is unsigned for performance reasons)

    So revert:

    # c300ba2: sched_clock: and multiplier for TSC to gtod drift
    # c0c8773: sched_clock: only update deltas with local reads.
    # af52a90: sched_clock: stop maximum check on NO HZ
    # f7cce27: sched_clock: widen the max and min time

    This solves the interactivity problems.

    Signed-off-by: Ingo Molnar
    Acked-by: Peter Zijlstra
    Acked-by: Mike Galbraith

    Ingo Molnar
     

25 Jul, 2008

1 commit

19 Jul, 2008

2 commits

  • 9b610fda0   Merge branch 'linus' into timers/nohz Browse Code »
    Ingo Molnar
     
  • b8f8c3cf0   nohz: prevent tick stop outside of the idle loop ... Browse Code »

    Jack Ren and Eric Miao tracked down the following long standing
    problem in the NOHZ code:

    scheduler switch to idle task
    enable interrupts

    Window starts here

    ----> interrupt happens (does not set NEED_RESCHED)
    irq_exit() stops the tick

    ----> interrupt happens (does set NEED_RESCHED)

    return from schedule()

    cpu_idle(): preempt_disable();

    Window ends here

    The interrupts can happen at any point inside the race window. The
    first interrupt stops the tick, the second one causes the scheduler to
    rerun and switch away from idle again and we end up with the tick
    disabled.

    The fact that it needs two interrupts where the first one does not set
    NEED_RESCHED and the second one does made the bug obscure and extremly
    hard to reproduce and analyse. Kudos to Jack and Eric.

    Solution: Limit the NOHZ functionality to the idle loop to make sure
    that we can not run into such a situation ever again.

    cpu_idle()
    {
    preempt_disable();

    while(1) {
    tick_nohz_stop_sched_tick(1); ,
    Debugged-by: eric miao
    Signed-off-by: Thomas Gleixner

    Thomas Gleixner
     

16 Jul, 2008

2 commits

11 Jul, 2008

2 commits

  • af52a90a1   sched_clock: stop maximum check on NO HZ ... Browse Code »

    Working with ftrace I would get large jumps of 11 millisecs or more with
    the clock tracer. This killed the latencing timings of ftrace and also
    caused the irqoff self tests to fail.

    What was happening is with NO_HZ the idle would stop the jiffy counter and
    before the jiffy counter was updated the sched_clock would have a bad
    delta jiffies to compare with the gtod with the maximum.

    The jiffies would stop and the last sched_tick would record the last gtod.
    On wakeup, the sched clock update would compare the gtod + delta jiffies
    (which would be zero) and compare it to the TSC. The TSC would have
    correctly (with a stable TSC) moved forward several jiffies. But because the
    jiffies has not been updated yet the clock would be prevented from moving
    forward because it would appear that the TSC jumped too far ahead.

    The clock would then virtually stop, until the jiffies are updated. Then
    the next sched clock update would see that the clock was very much behind
    since the delta jiffies is now correct. This would then jump the clock
    forward by several jiffies.

    This caused ftrace to report several milliseconds of interrupts off
    latency at every resume from NO_HZ idle.

    This patch adds hooks into the nohz code to disable the checking of the
    maximum clock update when nohz is in effect. It resumes the max check
    when nohz has updated the jiffies again.

    Signed-off-by: Steven Rostedt
    Cc: Steven Rostedt
    Cc: Peter Zijlstra
    Cc: Andrew Morton
    Signed-off-by: Ingo Molnar

    Steven Rostedt
     
  • 857f3fd7a   nohz: don't stop idle tick if softirqs are pending. ... Browse Code »

    In case a cpu goes idle but softirqs are pending only an error message is
    printed to the console. It may take a very long time until the pending
    softirqs will finally be executed. Worst case would be a hanging system.

    With this patch the timer tick just continues and the softirqs will be
    executed after the next interrupt. Still a delay but better than a
    hanging system.

    Currently we have at least two device drivers on s390 which under certain
    circumstances schedule a tasklet from process context. This is a reason
    why we can end up with pending softirqs when going idle. Fixing these
    drivers seems to be non-trivial.
    However there is no question that the drivers should be fixed.
    This patch shouldn't be considered as a bug fix. It just is intended to
    keep a system running even if device drivers are buggy.

    Signed-off-by: Heiko Carstens
    Cc: Jan Glauber
    Cc: Stefan Weinhuber
    Cc: Andrew Morton
    Signed-off-by: Ingo Molnar

    Heiko Carstens
     

30 May, 2008

2 commits

25 Apr, 2008

1 commit

  • 126e01bf9   softlockup: fix NOHZ wakeup ... Browse Code »

    David Miller reported:

    |--------------->
    the following commit:

    | commit 27ec4407790d075c325e1f4da0a19c56953cce23
    | Author: Ingo Molnar
    | Date: Thu Feb 28 21:00:21 2008 +0100
    |
    | sched: make cpu_clock() globally synchronous
    |
    | Alexey Zaytsev reported (and bisected) that the introduction of
    | cpu_clock() in printk made the timestamps jump back and forth.
    |
    | Make cpu_clock() more reliable while still keeping it fast when it's
    | called frequently.
    |
    | Signed-off-by: Ingo Molnar

    causes watchdog triggers when a cpu exits NOHZ state when it has been
    there for >= the soft lockup threshold, for example here are some
    messages from a 128 cpu Niagara2 box:

    [ 168.106406] BUG: soft lockup - CPU#11 stuck for 128s! [dd:3239]
    [ 168.989592] BUG: soft lockup - CPU#21 stuck for 86s! [swapper:0]
    [ 168.999587] BUG: soft lockup - CPU#29 stuck for 91s! [make:4511]
    [ 168.999615] BUG: soft lockup - CPU#2 stuck for 85s! [swapper:0]
    [ 169.020514] BUG: soft lockup - CPU#37 stuck for 91s! [swapper:0]
    [ 169.020514] BUG: soft lockup - CPU#45 stuck for 91s! [sh:4515]
    [ 169.020515] BUG: soft lockup - CPU#69 stuck for 92s! [swapper:0]
    [ 169.020515] BUG: soft lockup - CPU#77 stuck for 92s! [swapper:0]
    [ 169.020515] BUG: soft lockup - CPU#61 stuck for 92s! [swapper:0]
    [ 169.112554] BUG: soft lockup - CPU#85 stuck for 92s! [swapper:0]
    [ 169.112554] BUG: soft lockup - CPU#101 stuck for 92s! [swapper:0]
    [ 169.112554] BUG: soft lockup - CPU#109 stuck for 92s! [swapper:0]
    [ 169.112554] BUG: soft lockup - CPU#117 stuck for 92s! [swapper:0]
    [ 169.171483] BUG: soft lockup - CPU#40 stuck for 80s! [dd:3239]
    [ 169.331483] BUG: soft lockup - CPU#13 stuck for 86s! [swapper:0]
    [ 169.351500] BUG: soft lockup - CPU#43 stuck for 101s! [dd:3239]
    [ 169.531482] BUG: soft lockup - CPU#9 stuck for 129s! [mkdir:4565]
    [ 169.595754] BUG: soft lockup - CPU#20 stuck for 93s! [swapper:0]
    [ 169.626787] BUG: soft lockup - CPU#52 stuck for 93s! [swapper:0]
    [ 169.626787] BUG: soft lockup - CPU#84 stuck for 92s! [swapper:0]
    [ 169.636812] BUG: soft lockup - CPU#116 stuck for 94s! [swapper:0]

    It's simple enough to trigger this by doing a 10 minute sleep after a
    fresh bootup then starting a parallel kernel build.

    I suspect this might be reintroducing a problem we've had and fixed
    before, see the thread:

    http://marc.info/?l=linux-kernel&m=119546414004065&w=2

    Ingo Molnar
     

20 Apr, 2008

1 commit

  • d0b27fa77   sched: rt-group: synchonised bandwidth period ... Browse Code »

    Various SMP balancing algorithms require that the bandwidth period
    run in sync.

    Possible improvements are moving the rt_bandwidth thing into root_domain
    and keeping a span per rt_bandwidth which marks throttled cpus.

    Signed-off-by: Peter Zijlstra
    Signed-off-by: Ingo Molnar

    Peter Zijlstra
     

17 Apr, 2008

1 commit

  • 903b8a8d4   clockevents: optimise tick_nohz_stop_sched_tick() a bit ... Browse Code »

    Call
    ts = &per_cpu(tick_cpu_sched, cpu);
    and
    cpu = smp_processor_id();
    once instead of twice.

    No functional change done, as changed code runs with local irq off.
    Reduces source lines and text size (20bytes on x86_64).

    [ akpm@linux-foundation.org: Build fix ]

    Signed-off-by: Karsten Wiese
    Cc: Andrew Morton
    Signed-off-by: Thomas Gleixner

    Karsten Wiese
     

09 Mar, 2008

1 commit

01 Mar, 2008

1 commit

  • 2232c2d8e   rcu: add support for dynamic ticks and preempt rcu ... Browse Code »

    The PREEMPT-RCU can get stuck if a CPU goes idle and NO_HZ is set. The
    idle CPU will not progress the RCU through its grace period and a
    synchronize_rcu my get stuck. Without this patch I have a box that will
    not boot when PREEMPT_RCU and NO_HZ are set. That same box boots fine
    with this patch.

    This patch comes from the -rt kernel where it has been tested for
    several months.

    Signed-off-by: Steven Rostedt
    Signed-off-by: Paul E. McKenney
    Signed-off-by: Ingo Molnar

    Steven Rostedt
     

09 Feb, 2008

1 commit

02 Feb, 2008

1 commit

  • 5df7fa1c6   tick-sched: add more debug information ... Browse Code »

    To allow better diagnosis of tick-sched related, especially NOHZ
    related problems, we need to know when the last wakeup via an irq
    happened and when the CPU left the idle state.

    Add two fields (idle_waketime, idle_exittime) to the tick_sched
    structure and add them to the timer_list output.

    Signed-off-by: Thomas Gleixner
    Signed-off-by: Ingo Molnar

    Thomas Gleixner
     

30 Jan, 2008

3 commits

  • 6378ddb59   time: track accurate idle time with tick_sched.idle_sleeptime ... Browse Code »

    Current idle time in kstat is based on jiffies and is coarse grained.
    tick_sched.idle_sleeptime is making some attempt to keep track of idle time
    in a fine grained manner. But, it is not handling the time spent in
    interrupts fully.

    Make tick_sched.idle_sleeptime accurate with respect to time spent on
    handling interrupts and also add tick_sched.idle_lastupdate, which keeps
    track of last time when idle_sleeptime was updated.

    This statistics will be crucial for cpufreq-ondemand governor, which can
    shed some conservative gaurd band that is uses today while setting the
    frequency. The ondemand changes that uses the exact idle time is coming
    soon.

    Signed-off-by: Venkatesh Pallipadi
    Signed-off-by: Andrew Morton
    Signed-off-by: Ingo Molnar
    Signed-off-by: Thomas Gleixner

    Venki Pallipadi
     
  • b10db7f0d   time: more timer related cleanups ... Browse Code »

    I was confused by FSEC = 10^15 NSEC statement, plus small whitespace
    fixes. When there's copyright, there should be GPL.

    Signed-off-by: Pavel Machek
    Signed-off-by: Ingo Molnar
    Signed-off-by: Thomas Gleixner

    Pavel Machek
     
  • 4c9dc6412   time: timer cleanups ... Browse Code »

    Small cleanups to tick-related code. Wrong preempt count is followed
    by BUG(), so it is hardly KERN_WARNING.

    Signed-off-by: Pavel Machek
    Cc: john stultz
    Signed-off-by: Andrew Morton
    Signed-off-by: Ingo Molnar
    Signed-off-by: Thomas Gleixner

    Pavel Machek
     

26 Jan, 2008

2 commits

28 Nov, 2007

1 commit

  • d39382044   softlockup: fix false positives on CONFIG_NOHZ ... Browse Code »

    David Miller reported soft lockup false-positives that trigger
    on NOHZ due to CPUs idling for more than 10 seconds.

    The solution is touch the softlockup watchdog when we return from
    idle. (by definition we are not 'locked up' when we were idle)

    http://bugzilla.kernel.org/show_bug.cgi?id=9409

    Reported-by: David Miller
    Signed-off-by: Thomas Gleixner
    Signed-off-by: Ingo Molnar

    Thomas Gleixner
     

06 Nov, 2007

1 commit

29 Oct, 2007

1 commit

20 Oct, 2007

1 commit

  • c4ec20717   Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 ... Browse Code »

    * 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (41 commits)
    ACPICA: hw: Don't carry spinlock over suspend
    ACPICA: hw: remove use_lock flag from acpi_hw_register_{read, write}
    ACPI: cpuidle: port idle timer suspend/resume workaround to cpuidle
    ACPI: clean up acpi_enter_sleep_state_prep
    Hibernation: Make sure that ACPI is enabled in acpi_hibernation_finish
    ACPI: suppress uninitialized var warning
    cpuidle: consolidate 2.6.22 cpuidle branch into one patch
    ACPI: thinkpad-acpi: skip blanks before the data when parsing sysfs
    ACPI: AC: Add sysfs interface
    ACPI: SBS: Add sysfs alarm
    ACPI: SBS: Add ACPI_PROCFS around procfs handling code.
    ACPI: SBS: Add support for power_supply class (and sysfs)
    ACPI: SBS: Make SBS reads table-driven.
    ACPI: SBS: Simplify data structures in SBS
    ACPI: SBS: Split host controller (ACPI0001) from SBS driver (ACPI0002)
    ACPI: EC: Add new query handler to list head.
    ACPI: Add acpi_bus_generate_event4() function
    ACPI: Battery: add sysfs alarm
    ACPI: Battery: Add sysfs support
    ACPI: Battery: Misc clean-ups, no functional changes
    ...

    Fix up conflicts in drivers/misc/thinkpad_acpi.[ch] manually

    Linus Torvalds
     

17 Oct, 2007

1 commit

  • b2d9323d1   Use num_possible_cpus() instead of NR_CPUS for timer distribution ... Browse Code »

    To avoid lock contention, we distribute the sched_timer calls across the
    cpus so they do not trigger at the same instant. However, I used NR_CPUS,
    which can cause needless grouping on small smp systems depending on your
    kernel config. This patch converts to using num_possible_cpus() so we
    spread it as evenly as possible on every machine.

    Briefly tested w/ NR_CPUS=255 and verified reduced contention.

    Signed-off-by: John Stultz
    Acked-by: Thomas Gleixner
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    john stultz
     

10 Oct, 2007

1 commit

  • 4f86d3a8e   cpuidle: consolidate 2.6.22 cpuidle branch into one patch ... Browse Code »

    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
     

16 Sep, 2007

1 commit

  • 5e41d0d60   clockevents: prevent stale tick update on offline cpu ... Browse Code »

    Taking a cpu offline removes the cpu from the online mask before the
    CPU_DEAD notification is done. The clock events layer does the cleanup
    of the dead CPU from the CPU_DEAD notifier chain. tick_do_timer_cpu is
    used to avoid xtime lock contention by assigning the task of jiffies
    xtime updates to one CPU. If a CPU is taken offline, then this
    assignment becomes stale. This went unnoticed because most of the time
    the offline CPU went dead before the online CPU reached __cpu_die(),
    where the CPU_DEAD state is checked. In the case that the offline CPU did
    not reach the DEAD state before we reach __cpu_die(), the code in there
    goes to sleep for 100ms. Due to the stale time update assignment, the
    system is stuck forever.

    Take the assignment away when a cpu is not longer in the cpu_online_mask.
    We do this in the last call to tick_nohz_stop_sched_tick() when the offline
    CPU is on the way to the final play_dead() idle entry.

    Signed-off-by: Thomas Gleixner

    Thomas Gleixner
     

22 Jul, 2007

1 commit

  • 3704540b4   tick management: spread timer interrupt ... Browse Code »

    After discussing w/ Thomas over IRC, it seems the issue is the sched tick
    fires on every cpu at the same time, causing extra lock contention.

    This smaller change, adds an extra offset per cpu so the ticks don't line up.
    This patch also drops the idle latency from 40us down to under 20us.

    Signed-off-by: john stultz
    Signed-off-by: Thomas Gleixner
    Cc: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    john stultz
     

30 May, 2007

1 commit

  • eaad084bb   NOHZ: prevent multiplication overflow - stop timer for huge timeouts ... Browse Code »

    get_next_timer_interrupt() returns a delta of (LONG_MAX > 1) in case
    there is no timer pending. On 64 bit machines this results in a
    multiplication overflow in tick_nohz_stop_sched_tick().

    Reported by: Dave Miller

    Make the return value a constant and limit the return value to a 32 bit
    value.

    When the max timeout value is returned, we can safely stop the tick
    timer device. The max jiffies delta results in a 12 days timeout for
    HZ=1000.

    In the long term the get_next_timer_interrupt() code needs to be
    reworked to return ktime instead of jiffies, but we have to wait until
    the last users of the original NO_IDLE_HZ code are converted.

    Signed-off-by: Thomas Gleixner
    Acked-off-by: David S. Miller
    Signed-off-by: Linus Torvalds

    Thomas Gleixner
     

24 May, 2007

1 commit

09 May, 2007

2 commits

  • 46cb4b7c8   sched: dynticks idle load balancing ... Browse Code »

    Fix the process idle load balancing in the presence of dynticks. cpus for
    which ticks are stopped will sleep till the next event wakes it up.
    Potentially these sleeps can be for large durations and during which today,
    there is no periodic idle load balancing being done.

    This patch nominates an owner among the idle cpus, which does the idle load
    balancing on behalf of the other idle cpus. And once all the cpus are
    completely idle, then we can stop this idle load balancing too. Checks added
    in fast path are minimized. Whenever there are busy cpus in the system, there
    will be an owner(idle cpu) doing the system wide idle load balancing.

    Open items:
    1. Intelligent owner selection (like an idle core in a busy package).
    2. Merge with rcu's nohz_cpu_mask?

    Signed-off-by: Suresh Siddha
    Acked-by: Ingo Molnar
    Cc: Thomas Gleixner
    Cc: Nick Piggin
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Siddha, Suresh B
     
  • d3ed78245   highres/dyntick: prevent xtime lock contention ... Browse Code »

    While the !highres/!dyntick code assigns the duty of the do_timer() call to
    one specific CPU, this was dropped in the highres/dyntick part during
    development.

    Steven Rostedt discovered the xtime lock contention on highres/dyntick due
    to several CPUs trying to update jiffies.

    Add the single CPU assignement back. In the dyntick case this needs to be
    handled carefully, as the CPU which has the do_timer() duty must drop the
    assignement and let it be grabbed by another CPU, which is active.
    Otherwise the do_timer() calls would not happen during the long sleep.

    Signed-off-by: Thomas Gleixner
    Acked-by: Ingo Molnar
    Cc: Steven Rostedt
    Acked-by: Mark Lord
    Cc:
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Thomas Gleixner