Le 03/11/2021 à 22:31, Christophe JAILLET a écrit :
Use 'percpu_ref_tryget_live_rcu()' instead of 'percpu_ref_tryget_live()' to
save a few cycles when it is known that the rcu lock is already
taken/released.
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
fs/aio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/aio.c b/fs/aio.c
index 9c81cf611d65..d189ea13e10a 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1062,7 +1062,7 @@ static struct kioctx *lookup_ioctx(unsigned long ctx_id)
id = array_index_nospec(id, table->nr);
ctx = rcu_dereference(table->table[id]);
if (ctx && ctx->user_id == ctx_id) {
- if (percpu_ref_tryget_live(&ctx->users))
+ if (percpu_ref_tryget_live_rcu(&ctx->users))
ret = ctx;
}
out:
Hi,
gentle reminder.
Is this patch useful?
When I first posted it, percpu_ref_tryget_live_rcu() was really new.
Now it is part of linux since 5.16.
Saving a few cycles in a function with "lookup" in its name looks always
good to me.
CJ
