From b5691848893012c68ca79579d682245a5f91c361 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Fri, 13 May 2022 11:24:56 +0100 Subject: [PATCH] io_uring: avoid io-wq -EAGAIN looping for !IOPOLL BugLink: https://bugs.launchpad.net/bugs/1987451 [ Upstream commit e0deb6a025ae8c850dc8685be39fb27b06c88736 ] If an opcode handler semi-reliably returns -EAGAIN, io_wq_submit_work() might continue busily hammer the same handler over and over again, which is not ideal. The -EAGAIN handling in question was put there only for IOPOLL, so restrict it to IOPOLL mode only where there is no other recourse than to retry as we cannot wait. Fixes: def596e9557c9 ("io_uring: support for IO polling") Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/f168b4f24181942f3614dd8ff648221736f572e6.1652433740.git.asml.silence@gmail.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin Signed-off-by: Kamal Mostafa Signed-off-by: Stefan Bader --- fs/io_uring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 0c5dcda0b622..9bff14c5e2b2 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -6866,7 +6866,7 @@ static void io_wq_submit_work(struct io_wq_work *work) * forcing a sync submission from here, since we can't * wait for request slots on the block side. */ - if (ret != -EAGAIN) + if (ret != -EAGAIN || !(req->ctx->flags & IORING_SETUP_IOPOLL)) break; cond_resched(); } while (1); -- 2.39.5