rcuscale: Move shutdown from wait_event() to wait_event_idle()

[ Upstream commit ef1ef3d476 ]

The rcu_scale_shutdown() and kfree_scale_shutdown() kthreads/functions
use wait_event() to wait for the rcuscale test to complete.  However,
each updater thread in such a test waits for at least 100 grace periods.
If each grace period takes more than 1.2 seconds, which is long, but
not insanely so, this can trigger the hung-task timeout.

This commit therefore replaces those wait_event() calls with calls to
wait_event_idle(), which do not trigger the hung-task timeout.

Reported-by: kernel test robot <yujie.liu@intel.com>
Reported-by: Liam Howlett <liam.howlett@oracle.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: Yujie Liu <yujie.liu@intel.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Stable-dep-of: 23fc8df26d ("rcu/rcuscale: Stop kfree_scale_thread thread(s) after unloading rcuscale")
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Paul E. McKenney 2023-01-31 12:08:54 -08:00 committed by Greg Kroah-Hartman
parent a6d33ea305
commit 751cb95117

View file

@ -609,8 +609,7 @@ static int compute_real(int n)
static int
rcu_scale_shutdown(void *arg)
{
wait_event(shutdown_wq,
atomic_read(&n_rcu_scale_writer_finished) >= nrealwriters);
wait_event_idle(shutdown_wq, atomic_read(&n_rcu_scale_writer_finished) >= nrealwriters);
smp_mb(); /* Wake before output. */
rcu_scale_cleanup();
kernel_power_off();
@ -736,8 +735,8 @@ kfree_scale_cleanup(void)
static int
kfree_scale_shutdown(void *arg)
{
wait_event(shutdown_wq,
atomic_read(&n_kfree_scale_thread_ended) >= kfree_nrealthreads);
wait_event_idle(shutdown_wq,
atomic_read(&n_kfree_scale_thread_ended) >= kfree_nrealthreads);
smp_mb(); /* Wake before output. */