lkml.org 
[lkml]   [2007]   [Mar]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Subject[PATCH] clockevents: Fix suspend/resume to disk hangs
    From
    Date
    I finally found a dual core box, which survives suspend/resume without
    crashing in the middle of nowhere. Sigh, I never figured out from the
    code and the bug reports what's going on.

    The observed hangs are caused by a stale state transition of the clock
    event devices, which keeps the RCU synchronization away from completion,
    when the non boot CPU is brought back up.

    The suspend/resume in oneshot mode needs the similar care as the
    periodic mode during suspend to RAM. My assumption that the state
    transitions during the different shutdown/bringups of s2disk would go
    through the periodic boot phase and then switch over to highres resp.
    nohz mode were simply wrong.

    Add the appropriate suspend / resume handling for the non periodic
    modes.

    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

    diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
    index 5567745..eadfce2 100644
    --- a/kernel/time/tick-broadcast.c
    +++ b/kernel/time/tick-broadcast.c
    @@ -307,12 +307,19 @@ int tick_resume_broadcast(void)
    spin_lock_irqsave(&tick_broadcast_lock, flags);

    bc = tick_broadcast_device.evtdev;
    - if (bc) {
    - if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC &&
    - !cpus_empty(tick_broadcast_mask))
    - tick_broadcast_start_periodic(bc);

    - broadcast = cpu_isset(smp_processor_id(), tick_broadcast_mask);
    + if (bc) {
    + switch (tick_broadcast_device.mode) {
    + case TICKDEV_MODE_PERIODIC:
    + if(!cpus_empty(tick_broadcast_mask))
    + tick_broadcast_start_periodic(bc);
    + broadcast = cpu_isset(smp_processor_id(),
    + tick_broadcast_mask);
    + break;
    + case TICKDEV_MODE_ONESHOT:
    + broadcast = tick_resume_broadcast_oneshot(bc);
    + break;
    + }
    }
    spin_unlock_irqrestore(&tick_broadcast_lock, flags);

    @@ -347,6 +354,16 @@ static int tick_broadcast_set_event(ktime_t expires, int force)
    }
    }

    +int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
    +{
    + clockevents_set_mode(bc, CLOCK_EVT_MODE_ONESHOT);
    +
    + if(!cpus_empty(tick_broadcast_oneshot_mask))
    + tick_broadcast_set_event(ktime_get(), 1);
    +
    + return cpu_isset(smp_processor_id(), tick_broadcast_oneshot_mask);
    +}
    +
    /*
    * Reprogram the broadcast device:
    *
    diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
    index 43ba1bd..bfda3f7 100644
    --- a/kernel/time/tick-common.c
    +++ b/kernel/time/tick-common.c
    @@ -298,18 +298,17 @@ static void tick_shutdown(unsigned int *cpup)
    spin_unlock_irqrestore(&tick_device_lock, flags);
    }

    -static void tick_suspend_periodic(void)
    +static void tick_suspend(void)
    {
    struct tick_device *td = &__get_cpu_var(tick_cpu_device);
    unsigned long flags;

    spin_lock_irqsave(&tick_device_lock, flags);
    - if (td->mode == TICKDEV_MODE_PERIODIC)
    - clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_SHUTDOWN);
    + clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_SHUTDOWN);
    spin_unlock_irqrestore(&tick_device_lock, flags);
    }

    -static void tick_resume_periodic(void)
    +static void tick_resume(void)
    {
    struct tick_device *td = &__get_cpu_var(tick_cpu_device);
    unsigned long flags;
    @@ -317,6 +316,8 @@ static void tick_resume_periodic(void)
    spin_lock_irqsave(&tick_device_lock, flags);
    if (td->mode == TICKDEV_MODE_PERIODIC)
    tick_setup_periodic(td->evtdev, 0);
    + else
    + tick_resume_oneshot();
    spin_unlock_irqrestore(&tick_device_lock, flags);
    }

    @@ -348,13 +349,13 @@ static int tick_notify(struct notifier_block *nb, unsigned long reason,
    break;

    case CLOCK_EVT_NOTIFY_SUSPEND:
    - tick_suspend_periodic();
    + tick_suspend();
    tick_suspend_broadcast();
    break;

    case CLOCK_EVT_NOTIFY_RESUME:
    if (!tick_resume_broadcast())
    - tick_resume_periodic();
    + tick_resume();
    break;

    default:
    diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
    index 75890ef..c9d203b 100644
    --- a/kernel/time/tick-internal.h
    +++ b/kernel/time/tick-internal.h
    @@ -19,12 +19,13 @@ extern void tick_setup_oneshot(struct clock_event_device *newdev,
    extern int tick_program_event(ktime_t expires, int force);
    extern void tick_oneshot_notify(void);
    extern int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *));
    -
    +extern void tick_resume_oneshot(void);
    # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
    extern void tick_broadcast_setup_oneshot(struct clock_event_device *bc);
    extern void tick_broadcast_oneshot_control(unsigned long reason);
    extern void tick_broadcast_switch_to_oneshot(void);
    extern void tick_shutdown_broadcast_oneshot(unsigned int *cpup);
    +extern int tick_resume_broadcast_oneshot(struct clock_event_device *bc);
    # else /* BROADCAST */
    static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
    {
    @@ -43,6 +44,10 @@ void tick_setup_oneshot(struct clock_event_device *newdev,
    {
    BUG();
    }
    +static inline void tick_resume_oneshot(void)
    +{
    + BUG();
    +}
    static inline int tick_program_event(ktime_t expires, int force)
    {
    return 0;
    @@ -54,6 +59,10 @@ static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
    }
    static inline void tick_broadcast_oneshot_control(unsigned long reason) { }
    static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
    +static inline int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
    +{
    + return 0;
    +}
    #endif /* !TICK_ONESHOT */

    /*
    diff --git a/kernel/time/tick-oneshot.c b/kernel/time/tick-oneshot.c
    index 2e8b7ff..f6997ab 100644
    --- a/kernel/time/tick-oneshot.c
    +++ b/kernel/time/tick-oneshot.c
    @@ -41,6 +41,18 @@ int tick_program_event(ktime_t expires, int force)
    }

    /**
    + * tick_resume_onshot - resume oneshot mode
    + */
    +void tick_resume_oneshot(void)
    +{
    + struct tick_device *td = &__get_cpu_var(tick_cpu_device);
    + struct clock_event_device *dev = td->evtdev;
    +
    + clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
    + tick_program_event(ktime_get(), 1);
    +}
    +
    +/**
    * tick_setup_oneshot - setup the event device for oneshot mode (hres or nohz)
    */
    void tick_setup_oneshot(struct clock_event_device *newdev,

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2007-03-17 00:21    [W:0.034 / U:3.068 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site