io_uring/napi: check napi_enabled in io_napi_add() before proceeding

doing so avoids the overhead of adding napi ids to all the rings that do
not enable napi.

if no id is added to napi_list because napi is disabled,
__io_napi_busy_loop() will not be called.

Signed-off-by: Olivier Langlois <olivier@trillion01.com>
Fixes: b4ccc4dd13 ("io_uring/napi: enable even with a timeout of 0")
Link: https://lore.kernel.org/r/bd989ccef5fda14f5fd9888faf4fefcf66bd0369.1723400131.git.olivier@trillion01.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Olivier Langlois 2024-08-11 14:07:11 -04:00 committed by Jens Axboe
parent 8fe8ac24ad
commit 84f2eecf95
2 changed files with 2 additions and 2 deletions

View file

@ -302,7 +302,7 @@ void __io_napi_busy_loop(struct io_ring_ctx *ctx, struct io_wait_queue *iowq)
{
iowq->napi_prefer_busy_poll = READ_ONCE(ctx->napi_prefer_busy_poll);
if (!(ctx->flags & IORING_SETUP_SQPOLL) && ctx->napi_enabled)
if (!(ctx->flags & IORING_SETUP_SQPOLL))
io_napi_blocking_busy_loop(ctx, iowq);
}

View file

@ -55,7 +55,7 @@ static inline void io_napi_add(struct io_kiocb *req)
struct io_ring_ctx *ctx = req->ctx;
struct socket *sock;
if (!READ_ONCE(ctx->napi_busy_poll_dt))
if (!READ_ONCE(ctx->napi_enabled))
return;
sock = sock_from_file(req->file);