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| author | Thomas Gleixner <tglx@linutronix.de> | 2008-09-29 15:47:42 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2008-09-29 17:09:14 +0200 |
| commit | ccc7dadf736639da86f3e0c86832c11a66fc8221 (patch) | |
| tree | 3f1c0df0a291fec4a10d72cc1ab278ad81e697c5 /include/linux/hrtimer.h | |
| parent | b00c1a99e7758f794923c61e5cd55268d61c9469 (diff) | |
| download | lwn-ccc7dadf736639da86f3e0c86832c11a66fc8221.tar.gz lwn-ccc7dadf736639da86f3e0c86832c11a66fc8221.zip | |
hrtimer: prevent migration of per CPU hrtimers
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 <tglx@linutronix.de>
Diffstat (limited to 'include/linux/hrtimer.h')
| -rw-r--r-- | include/linux/hrtimer.h | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index bdd88df1b4e5..2f245fe63bda 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -47,14 +47,22 @@ enum hrtimer_restart { * HRTIMER_CB_IRQSAFE: Callback may run in hardirq context * HRTIMER_CB_IRQSAFE_NO_RESTART: Callback may run in hardirq context and * does not restart the timer - * HRTIMER_CB_IRQSAFE_NO_SOFTIRQ: Callback must run in hardirq context - * Special mode for tick emultation + * HRTIMER_CB_IRQSAFE_PERCPU: Callback must run in hardirq context + * Special mode for tick emulation and + * scheduler timer. Such timers are per + * cpu and not allowed to be migrated on + * cpu unplug. + * HRTIMER_CB_IRQSAFE_UNLOCKED: Callback should run in hardirq context + * with timer->base lock unlocked + * used for timers which call wakeup to + * avoid lock order problems with rq->lock */ enum hrtimer_cb_mode { HRTIMER_CB_SOFTIRQ, HRTIMER_CB_IRQSAFE, HRTIMER_CB_IRQSAFE_NO_RESTART, - HRTIMER_CB_IRQSAFE_NO_SOFTIRQ, + HRTIMER_CB_IRQSAFE_PERCPU, + HRTIMER_CB_IRQSAFE_UNLOCKED, }; /* |