On Tue, Aug 04, 2026 at 12:03:39AM +0000, Bradley Morgan wrote:
> The do_pending kthread never sleeps. Its supposed to.
> kthread_do_pending_ms sets the gap between cleanups, and the docs
> say so too. But the sleep sits behind torture_must_stop(), and thats
> false while the test runs. So the kthread never sleeps. It just loops.
> It drains the pending lists over and over, no pause, and burns a full
> CPU for the whole test.
>
> Flip the check. With !torture_must_stop() it sleeps for
> kthread_do_pending_ms between passes. When the test stops it does one
> last cleanup and exits. Nothing left to do, so no sleep needed then.
>
> Fixes: 94d2e93c222e ("hazptrtorture: Add kthread to release deferred hazard
> pointers")
> Signed-off-by: Bradley Morgan <[email protected]>
Good catch, applied, thank you!
Thanx, Paul
> ---
> kernel/rcu/hazptrtorture.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/rcu/hazptrtorture.c b/kernel/rcu/hazptrtorture.c
> index 72aeb50668e9..7c8b5899fb01 100644
> --- a/kernel/rcu/hazptrtorture.c
> +++ b/kernel/rcu/hazptrtorture.c
> @@ -555,7 +555,7 @@ static int hazptr_torture_do_pending(void *arg)
> cpu = cpumask_next_wrap(cpu, cpu_possible_mask);
> hazptr_torture_do_one_pending(cpu, &rand);
> }
> - if (torture_must_stop())
> + if (!torture_must_stop())
> torture_hrtimeout_ms(kthread_do_pending_ms,
> USEC_PER_MSEC, &rand);
> // Omit stutter_wait() because this function needs to do
> cleanup.
> } while (!torture_must_stop());
> --
> 2.47.3
>
