Re: [PATCH] aio: Save a few cycles in 'lookup_ioctx()'

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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



[Index of Archives]     [Kernel Development]     [Kernel Announce]     [Kernel Newbies]     [Linux Networking Development]     [Share Photos]     [IDE]     [Security]     [Git]     [Netfilter]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Device Mapper]

  Powered by Linux