diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2021-03-09 09:55:57 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2021-03-17 16:34:11 +0100 |
| commit | 47c218dcae6587fb5bce30f1656b13e22391c8e3 (patch) | |
| tree | 0577017548da523ecaf141594aefd66291d036e7 /kernel/time | |
| parent | softirq: Make softirq control and processing RT aware (diff) | |
| download | linux-47c218dcae6587fb5bce30f1656b13e22391c8e3.tar.xz linux-47c218dcae6587fb5bce30f1656b13e22391c8e3.zip | |
tick/sched: Prevent false positive softirq pending warnings on RT
On RT a task which has soft interrupts disabled can block on a lock and
schedule out to idle while soft interrupts are pending. This triggers the
warning in the NOHZ idle code which complains about going idle with pending
soft interrupts. But as the task is blocked soft interrupt processing is
temporarily blocked as well which means that such a warning is a false
positive.
To prevent that check the per CPU state which indicates that a scheduled
out task has soft interrupts disabled.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210309085727.527563866@linutronix.de
Diffstat (limited to 'kernel/time')
| -rw-r--r-- | kernel/time/tick-sched.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index e10a4af88737..0cc55791b2b6 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -973,7 +973,7 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts) if (unlikely(local_softirq_pending())) { static int ratelimit; - if (ratelimit < 10 && + if (ratelimit < 10 && !local_bh_blocked() && (local_softirq_pending() & SOFTIRQ_STOP_IDLE_MASK)) { pr_warn("NOHZ tick-stop error: Non-RCU local softirq work is pending, handler #%02x!!!\n", (unsigned int) local_softirq_pending()); |