Commit ef1ef3d4 authored by Paul E. McKenney's avatar Paul E. McKenney Committed by Boqun Feng
Browse files

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



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: default avatarkernel test robot <yujie.liu@intel.com>
Reported-by: default avatarLiam Howlett <liam.howlett@oracle.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
Tested-by: default avatarYujie Liu <yujie.liu@intel.com>
Signed-off-by: default avatarBoqun Feng <boqun.feng@gmail.com>
parent 4f02ac23

kernel/rcu/rcuscale.c

+3 −4
Original line number Diff line number Diff line
@@ -631,8 +631,7 @@ 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();
@@ -771,7 +770,7 @@ kfree_scale_cleanup(void) 
static int

kfree_scale_shutdown(void *arg)

{

	wait_event(shutdown_wq,

	wait_event_idle(shutdown_wq,

			atomic_read(&n_kfree_scale_thread_ended) >= kfree_nrealthreads);



	smp_mb(); /* Wake before output. */