On Thu, Jun 02, 2011 at 03:04:26PM +0200, Peter Zijlstra wrote: > On Thu, 2011-06-02 at 15:52 +0800, Yong Zhang wrote: > > In sched_clock_local(), clock is calculated around ->tick_gtod even if > > that ->tick_gtod is stale for long time because we stays in idle state. > > You know ->tick_gtod is only updated in sched_clock_tick(); > > (well, no, there's idle callbacks as you said below) > > > IOW, when a cpu goes out of idle, sched_clock_tick() is called from > > tick_nohz_stop_idle() which is later than interrupt. > > Gah, that would be awefull and mean wakeups from interrupts were already > borken. /me goes look at code. > > irq_enter() -> tick_check_idle() -> tick_check_nohz() -> > tick_nohz_stop_idle() -> sched_clock_idle_wakeup_event() > > should update the thing before we run any isrs, right? Hmmm, you are right. But smp_reschedule_interrupt() doesn't call irq_enter()/irq_exit(), is that correct? Thanks, Yong -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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