From 53d69bdd5b19bb17602cb224e01aeed730ff3289 Mon Sep 17 00:00:00 2001 From: Olivier Langlois Date: Mon, 16 Sep 2024 15:17:56 -0400 Subject: io_uring/sqpoll: do the napi busy poll outside the submission block there are many small reasons justifying this change. 1. busy poll must be performed even on rings that have no iopoll and no new sqe. It is quite possible that a ring configured for inbound traffic with multishot be several hours without receiving new request submissions 2. NAPI busy poll does not perform any credential validation 3. If the thread is awaken by task work, processing the task work is prioritary over NAPI busy loop. This is why a second loop has been created after the io_sq_tw() call instead of doing the busy loop in __io_sq_thread() outside its credential acquisition block. Signed-off-by: Olivier Langlois Link: https://lore.kernel.org/r/de7679adf1249446bd47426db01d82b9603b7224.1726161831.git.olivier@trillion01.com Signed-off-by: Jens Axboe --- io_uring/sqpoll.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'io_uring') diff --git a/io_uring/sqpoll.c b/io_uring/sqpoll.c index 7c79685baeb1..b800be719260 100644 --- a/io_uring/sqpoll.c +++ b/io_uring/sqpoll.c @@ -196,9 +196,6 @@ static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries) ret = io_submit_sqes(ctx, to_submit); mutex_unlock(&ctx->uring_lock); - if (io_napi(ctx)) - ret += io_napi_sqpoll_busy_poll(ctx); - if (to_submit && wq_has_sleeper(&ctx->sqo_sq_wait)) wake_up(&ctx->sqo_sq_wait); if (creds) @@ -323,6 +320,10 @@ static int io_sq_thread(void *data) if (io_sq_tw(&retry_list, IORING_TW_CAP_ENTRIES_VALUE)) sqt_spin = true; + list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) + if (io_napi(ctx)) + io_napi_sqpoll_busy_poll(ctx); + if (sqt_spin || !time_after(jiffies, timeout)) { if (sqt_spin) { io_sq_update_worktime(sqd, &start); -- cgit v1.2.3