On Sat, Jan 25, 2025 at 06:59:06AM +0000, lizetao wrote:
-----Original Message----- From: Pavel Begunkov asml.silence@gmail.com Sent: Saturday, January 25, 2025 2:54 AM To: io-uring@vger.kernel.org; stable@vger.kernel.org Cc: asml.silence@gmail.com; Xan Charbonnet xan@charbonnet.com; Salvatore Bonaccorso carnil@debian.org Subject: [PATCH stable-6.1 1/1] io_uring: fix waiters missing wake ups
[ upstream commit 3181e22fb79910c7071e84a43af93ac89e8a7106 ]
There are reports of mariadb hangs, which is caused by a missing barrier in the waking code resulting in waiters losing events.
The problem was introduced in a backport 3ab9326f93ec4 ("io_uring: wake up optimisations"), and the change restores the barrier present in the original commit 3ab9326f93ec4 ("io_uring: wake up optimisations")
Reported by: Xan Charbonnet xan@charbonnet.com Fixes: 3ab9326f93ec4 ("io_uring: wake up optimisations") Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1093243#99 Signed-off-by: Pavel Begunkov asml.silence@gmail.com
io_uring/io_uring.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 9b58ba4616d40..e5a8ee944ef59 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -592,8 +592,10 @@ static inline void __io_cq_unlock_post_flush(struct io_ring_ctx *ctx) io_commit_cqring(ctx); spin_unlock(&ctx->completion_lock); io_commit_cqring_flush(ctx);
- if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN))
- if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN)) {
smp_mb();- }
}
void io_cq_unlock_post(struct io_ring_ctx *ctx)
2.47.1
Reviewed-by: Li Zetao lizetao1@huawei.com
Now queued up, thanks.
greg k-h