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![]() Impact: fix CPU hotplug hang on Power6 testbox On architectures that support offlining all cpus (at least powerpc/pseries), hot-unpluging the tick_do_timer_cpu can result in a system hang. This comes from the fact that if the cpu going down happens to be the cpu doing the tick, then as the tick_do_timer_cpu handover happens after the cpu is dead (via the CPU_DEAD notification), we're left without ticks, jiffies are frozen and any task relying on timers (msleep, ...) is stuck. That's particularly the case for the cpu looping in __cpu_die() waiting for the dying cpu to be dead. This patch addresses this by having the tick_do_timer_cpu handover happen earlier during the CPU_DYING notification. For this, a new clockevent notification type is introduced (CLOCK_EVT_NOTIFY_CPU_DYING) which is triggered in hrtimer_cpu_notify(). Signed-off-by: Sebastien Dugue <sebastien.dugue@bull.net> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> |
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.. | ||
clockevents.c | ||
clocksource.c | ||
jiffies.c | ||
Kconfig | ||
Makefile | ||
ntp.c | ||
tick-broadcast.c | ||
tick-common.c | ||
tick-internal.h | ||
tick-oneshot.c | ||
tick-sched.c | ||
timekeeping.c | ||
timer_list.c | ||
timer_stats.c |