Messages in this thread | | | Date | Fri, 12 Aug 2022 06:54:09 +0200 | Subject | Re: [PATCH] aio: Save a few cycles in 'lookup_ioctx()' | From | Christophe JAILLET <> |
| |
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@wanadoo.fr> > --- > 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
| |