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| author | Wanpeng Li <wanpeng.li@hotmail.com> | 2016-09-07 18:51:13 +0800 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2016-09-13 17:53:52 +0200 |
| commit | 57ccdf449f962ab5fc8cbf26479402f13bdb8be7 (patch) | |
| tree | 89cd6859175a3aa2503903af7d11813e2edabddb /kernel | |
| parent | 2ea3401e2a84eed3f5f55b2075706f88df160d85 (diff) | |
| download | blackbird-op-linux-57ccdf449f962ab5fc8cbf26479402f13bdb8be7.tar.gz blackbird-op-linux-57ccdf449f962ab5fc8cbf26479402f13bdb8be7.zip | |
tick/nohz: Prevent stopping the tick on an offline CPU
can_stop_full_tick() has no check for offline cpus. So it allows to stop
the tick on an offline cpu from the interrupt return path, which is wrong
and subsequently makes irq_work_needs_cpu() warn about being called for an
offline cpu.
Commit f7ea0fd639c2c4 ("tick: Don't invoke tick_nohz_stop_sched_tick() if
the cpu is offline") added prevention for can_stop_idle_tick(), but forgot
to do the same in can_stop_full_tick(). Add it.
[ tglx: Massaged changelog ]
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1473245473-4463-1-git-send-email-wanpeng.li@hotmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/time/tick-sched.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 2ec7c00228f3..3bcb61b52f6c 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -186,10 +186,13 @@ static bool check_tick_dependency(atomic_t *dep) return false; } -static bool can_stop_full_tick(struct tick_sched *ts) +static bool can_stop_full_tick(int cpu, struct tick_sched *ts) { WARN_ON_ONCE(!irqs_disabled()); + if (unlikely(!cpu_online(cpu))) + return false; + if (check_tick_dependency(&tick_dep_mask)) return false; @@ -843,7 +846,7 @@ static void tick_nohz_full_update_tick(struct tick_sched *ts) if (!ts->tick_stopped && ts->nohz_mode == NOHZ_MODE_INACTIVE) return; - if (can_stop_full_tick(ts)) + if (can_stop_full_tick(cpu, ts)) tick_nohz_stop_sched_tick(ts, ktime_get(), cpu); else if (ts->tick_stopped) tick_nohz_restart_sched_tick(ts, ktime_get()); |
