[PATCH 2/3] test-ww_mutex: Move work to its own UNBOUND workqueue

From: John Stultz
Date: Thu Jul 31 2025 - 22:34:24 EST


The test-ww_mutex test already allocates its own workqueue
so be sure to use it for the mtx.work and abba.work rather
then the default system workqueue.

This resolves numerous messages of the sort:
"workqueue: test_abba_work hogged CPU... consider switching to WQ_UNBOUND"
"workqueue: test_mutex_work hogged CPU... consider switching to WQ_UNBOUND"

Signed-off-by: John Stultz <jstultz@xxxxxxxxxx>
---
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Waiman Long <longman@xxxxxxxxxx>
Cc: Boqun Feng <boqun.feng@xxxxxxxxx>
Cc: "Paul E . McKenney" <paulmck@xxxxxxxxxx>
Cc: Joel Fernandes <joelagnelf@xxxxxxxxxx>
Cc: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
Cc: Suleiman Souhlal <suleiman@xxxxxxxxxx>
Cc: kernel-team@xxxxxxxxxxx
---
kernel/locking/test-ww_mutex.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/locking/test-ww_mutex.c b/kernel/locking/test-ww_mutex.c
index 20f509ca17e16..11bc467c286aa 100644
--- a/kernel/locking/test-ww_mutex.c
+++ b/kernel/locking/test-ww_mutex.c
@@ -72,7 +72,7 @@ static int __test_mutex(struct ww_class *class, unsigned int flags)
init_completion(&mtx.done);
mtx.flags = flags;

- schedule_work(&mtx.work);
+ queue_work(wq, &mtx.work);

wait_for_completion(&mtx.ready);
ww_mutex_lock(&mtx.mutex, (flags & TEST_MTX_CTX) ? &ctx : NULL);
@@ -234,7 +234,7 @@ static int test_abba(struct ww_class *class, bool trylock, bool resolve)
abba.trylock = trylock;
abba.resolve = resolve;

- schedule_work(&abba.work);
+ queue_work(wq, &abba.work);

ww_acquire_init_noinject(&ctx, class);
if (!trylock)
--
2.50.1.565.gc32cd1483b-goog