This is a note to let you know that I've just added the patch titled
io_uring: allow conditional reschedule for intensive iterators
to the 5.14-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-allow-conditional-reschedule-for-intensive-.patch
and it can be found in the queue-5.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit cfcd1a38f6c74d200c718354da9be37da0875dfc
Author: Jens Axboe <axboe@xxxxxxxxx>
Date: Fri Sep 24 07:12:27 2021 -0600
io_uring: allow conditional reschedule for intensive iterators
[ Upstream commit 8bab4c09f24ec8d4a7a78ab343620f89d3a24804 ]
If we have a lot of threads and rings, the tctx list can get quite big.
This is especially true if we keep creating new threads and rings.
Likewise for the provided buffers list. Be nice and insert a conditional
reschedule point while iterating the nodes for deletion.
Link: https://lore.kernel.org/io-uring/00000000000064b6b405ccb41113@xxxxxxxxxx/
Reported-by: syzbot+111d2a03f51f5ae73775@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 699a08d724c2..675216f7022d 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8648,8 +8648,10 @@ static void io_destroy_buffers(struct io_ring_ctx *ctx)
struct io_buffer *buf;
unsigned long index;
- xa_for_each(&ctx->io_buffers, index, buf)
+ xa_for_each(&ctx->io_buffers, index, buf) {
__io_remove_buffers(ctx, buf, index, -1U);
+ cond_resched();
+ }
}
static void io_req_cache_free(struct list_head *list, struct task_struct *tsk)
@@ -9145,8 +9147,10 @@ static void io_uring_clean_tctx(struct io_uring_task *tctx)
struct io_tctx_node *node;
unsigned long index;
- xa_for_each(&tctx->xa, index, node)
+ xa_for_each(&tctx->xa, index, node) {
io_uring_del_tctx_node(index);
+ cond_resched();
+ }
if (wq) {
/*
* Must be after io_uring_del_task_file() (removes nodes under
