[PATCH v7 11/11] workqueue: Make queue_rcu_work() use call_rcu_flush()

From: Joel Fernandes (Google)
Date: Mon Oct 03 2022 - 22:43:21 EST


From: Uladzislau Rezki <urezki@xxxxxxxxx>

call_rcu() changes to save power will slow down RCU workqueue items
queued via queue_rcu_work(). This may not be an issue, however we cannot
assume that workqueue users are OK with long delays. Use
call_rcu_flush() API instead which reverts to the old behavior.

Signed-off-by: Uladzislau Rezki <urezki@xxxxxxxxx>
Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
---
kernel/workqueue.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index aeea9731ef80..fe1146d97f1a 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1771,7 +1771,7 @@ bool queue_rcu_work(struct workqueue_struct *wq, struct rcu_work *rwork)

if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) {
rwork->wq = wq;
- call_rcu(&rwork->rcu, rcu_work_rcufn);
+ call_rcu_flush(&rwork->rcu, rcu_work_rcufn);
return true;
}

--
2.38.0.rc1.362.ged0d419d3c-goog