diff mbox series

[v3] io_uring: do the sqpoll napi busy poll outside the submission block

Message ID 19905713556ad4195d1bf8c8c1e38fc2683b592b.1723502167.git.olivier@trillion01.com (mailing list archive)
State New
Headers show
Series [v3] io_uring: do the sqpoll napi busy poll outside the submission block | expand

Commit Message

Olivier Langlois July 30, 2024, 9:10 p.m. UTC
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 <olivier@trillion01.com>
---
 io_uring/sqpoll.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/io_uring/sqpoll.c b/io_uring/sqpoll.c
index cc4a25136030..b74db3988b7f 100644
--- a/io_uring/sqpoll.c
+++ b/io_uring/sqpoll.c
@@ -195,9 +195,6 @@  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)
@@ -322,6 +319,10 @@  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);