From b5bb3a24f69da92e0ec2a301452364333e45be03 Mon Sep 17 00:00:00 2001
From: Pavel Begunkov <asml.silence@gmail.com>
Date: Sat, 6 Mar 2021 11:02:16 +0000
Subject: [PATCH] io_uring: warn when ring exit takes too long
We use system_unbound_wq to run io_ring_exit_work(), so it's hard to
monitor whether removal hang or not. Add WARN_ONCE to catch hangs.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
fs/io_uring.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 01a7fa4a4889e0..945e54690b8110 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8560,6 +8560,7 @@ static void io_tctx_exit_cb(struct callback_head *cb)
static void io_ring_exit_work(struct work_struct *work)
{
struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx, exit_work);
+ unsigned long timeout = jiffies + HZ * 60 * 5;
struct io_tctx_exit exit;
struct io_tctx_node *node;
int ret;
@@ -8572,10 +8573,14 @@ static void io_ring_exit_work(struct work_struct *work)
*/
do {
io_uring_try_cancel_requests(ctx, NULL, NULL);
+
+ WARN_ON_ONCE(time_after(jiffies, timeout));
} while (!wait_for_completion_timeout(&ctx->ref_comp, HZ/20));
mutex_lock(&ctx->uring_lock);
while (!list_empty(&ctx->tctx_list)) {
+ WARN_ON_ONCE(time_after(jiffies, timeout));
+
node = list_first_entry(&ctx->tctx_list, struct io_tctx_node,
ctx_node);
exit.ctx = ctx;
--
GitLab