From f58680085478dd292435727210122960d38e8014 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 27 Jan 2023 09:50:31 -0700 Subject: io_uring: add reschedule point to handle_tw_list() If CONFIG_PREEMPT_NONE is set and the task_work chains are long, we could be running into issues blocking others for too long. Add a reschedule check in handle_tw_list(), and flush the ctx if we need to reschedule. Cc: stable@vger.kernel.org # 5.10+ Signed-off-by: Jens Axboe --- io_uring/io_uring.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'io_uring') diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index fab581a31dc1..acf6d9680d76 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -1179,10 +1179,16 @@ static unsigned int handle_tw_list(struct llist_node *node, /* if not contended, grab and improve batching */ *locked = mutex_trylock(&(*ctx)->uring_lock); percpu_ref_get(&(*ctx)->refs); - } + } else if (!*locked) + *locked = mutex_trylock(&(*ctx)->uring_lock); req->io_task_work.func(req, locked); node = next; count++; + if (unlikely(need_resched())) { + ctx_flush_and_put(*ctx, locked); + *ctx = NULL; + cond_resched(); + } } return count; -- cgit v1.2.3