This is a note to let you know that I've just added the patch titled
io_uring: remove iopoll spinlock
to the 6.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
io_uring-remove-iopoll-spinlock.patch
and it can be found in the queue-6.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 2dac1a159216b39ced8d78dba590c5d2f4249586 Mon Sep 17 00:00:00 2001
From: Pavel Begunkov <asml.silence@xxxxxxxxx>
Date: Wed, 23 Nov 2022 11:33:42 +0000
Subject: io_uring: remove iopoll spinlock
From: Pavel Begunkov <asml.silence@xxxxxxxxx>
commit 2dac1a159216b39ced8d78dba590c5d2f4249586 upstream.
This reverts commit 2ccc92f4effcfa1c51c4fcf1e34d769099d3cad4
io_req_complete_post() should now behave well even in case of IOPOLL, we
can remove completion_lock locking.
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Link: https://lore.kernel.org/r/7e171c8b530656b14a671c59100ca260e46e7f2a.1669203009.git.asml.silence@xxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
io_uring/rw.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -1063,7 +1063,6 @@ int io_do_iopoll(struct io_ring_ctx *ctx
else if (!pos)
return 0;
- spin_lock(&ctx->completion_lock);
prev = start;
wq_list_for_each_resume(pos, prev) {
struct io_kiocb *req = container_of(pos, struct io_kiocb, comp_list);
@@ -1078,11 +1077,11 @@ int io_do_iopoll(struct io_ring_ctx *ctx
req->cqe.flags = io_put_kbuf(req, 0);
__io_fill_cqe_req(req->ctx, req);
}
- io_commit_cqring(ctx);
- spin_unlock(&ctx->completion_lock);
+
if (unlikely(!nr_events))
return 0;
+ io_commit_cqring(ctx);
io_cqring_ev_posted_iopoll(ctx);
pos = start ? start->next : ctx->iopoll_list.first;
wq_list_cut(&ctx->iopoll_list, prev, start);
Patches currently in stable-queue which might be from asml.silence@xxxxxxxxx are
queue-6.0/io_uring-net-fix-cleanup-after-recycle.patch
queue-6.0/io_uring-protect-cq_timeouts-with-timeout_lock.patch
queue-6.0/io_uring-remove-iopoll-spinlock.patch
queue-6.0/io_uring-add-completion-locking-for-iopoll.patch
queue-6.0/io_uring-improve-io_double_lock_ctx-fail-handling.patch
