On 6/9/23 13:20, Hao Xu wrote:
From: Hao Xu <howeyxu@xxxxxxxxxxx>
acct->nr_workers should be decremented when we break the loop in
io_wq_worker().
Fixes: 78f8876c2d9f ("io-wq: exclusively gate signal based exit on get_signal() return")
Signed-off-by: Hao Xu <howeyxu@xxxxxxxxxxx>
---
io_uring/io-wq.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/io_uring/io-wq.c b/io_uring/io-wq.c
index b2715988791e..b70eebec2845 100644
--- a/io_uring/io-wq.c
+++ b/io_uring/io-wq.c
@@ -634,6 +634,10 @@ static int io_wq_worker(void *data)
if (!get_signal(&ksig))
continue;
+
+ raw_spin_lock(&wq->lock);
+ acct->nr_workers--;
+ raw_spin_unlock(&wq->lock);
Wouldn't it suffer the same race you fixed with the following?
commit 767a65e9f31789d80e41edd03a802314905e8fbf
Author: Hao Xu <haoxu@xxxxxxxxxxxxxxxxx>
Date: Sun Sep 12 03:40:52 2021 +0800
io-wq: fix potential race of acct->nr_workers
Even more, seems we fail to decrement nr_workers when the loop condition
fails, i.e.
while (!test_bit(IO_WQ_BIT_EXIT, &wq->state)) {
I.e. the patch looks legit, but what we currently have is a mess and we
have more work to do.
--
Pavel Begunkov
