Re: [PATCH RT 1/2] tasklet: Address a race resulting in double-enqueue
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: 2020-06-09 16:34:54
Also in:
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: 2020-06-09 16:34:54
Also in:
lkml
On 2020-06-09 11:17:53 [-0500], Tom Zanussi wrote:
Hi Sebastian,
Hi Tom,
I did find a problem with the patch when configured as !SMP since in that case the RUN flag is never set (will send a patch for that shortly), but that wouldn't be the case here.
How?
| #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT_FULL)
| static inline int tasklet_trylock(struct tasklet_struct *t)
| {
| return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
| }
I can't tell from the backtrace if he runs with RT or without but I
assumed RT. But yes, for !SMP && !RT it would explain it.
It would help to be able to reproduce it, but I haven't been able to yet. Tom
Sebastian