From 58d3be2c60d2cf4e6bb65bb6200fa39a7bc477f9 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Mon, 9 Aug 2021 13:04:17 +0100 Subject: [PATCH] io_uring: improve ctx hang handling If io_ring_exit_work() can't get it done in 5 minutes, something is going very wrong, don't keep spinning at HZ / 20 rate, it doesn't help and it may take much of CPU time if there is a lot of workers stuck as such. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/9e2d1ca81d569f6bc628af1a42ff6663bff7ce9c.1628471125.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- fs/io_uring.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 26a3ab9b6aed..af9472e3f17b 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -8795,6 +8795,7 @@ 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; + unsigned long interval = HZ / 20; struct io_tctx_exit exit; struct io_tctx_node *node; int ret; @@ -8819,8 +8820,11 @@ static void io_ring_exit_work(struct work_struct *work) io_sq_thread_unpark(sqd); } - WARN_ON_ONCE(time_after(jiffies, timeout)); - } while (!wait_for_completion_timeout(&ctx->ref_comp, HZ/20)); + if (WARN_ON_ONCE(time_after(jiffies, timeout))) { + /* there is little hope left, don't run it too often */ + interval = HZ * 60; + } + } while (!wait_for_completion_timeout(&ctx->ref_comp, interval)); init_completion(&exit.completion); init_task_work(&exit.task_work, io_tctx_exit_cb); -- 2.20.1