From 3fcee5a6d5414df8ff4ee22f2477bde76d34527c Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Mon, 6 Jul 2020 17:59:31 +0300 Subject: [PATCH] io_uring: briefly loose locks while reaping events It's not nice to hold @uring_lock for too long io_iopoll_reap_events(). For instance, the lock is needed to publish requests to @poll_list, and that locks out tasks doing that for no good reason. Loose it occasionally. Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe --- fs/io_uring.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 332008f346e3..6e3169834bf7 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2069,8 +2069,13 @@ static void io_iopoll_reap_events(struct io_ring_ctx *ctx) /* * Ensure we allow local-to-the-cpu processing to take place, * in this case we need to ensure that we reap all events. + * Also let task_work, etc. to progress by releasing the mutex */ - cond_resched(); + if (need_resched()) { + mutex_unlock(&ctx->uring_lock); + cond_resched(); + mutex_lock(&ctx->uring_lock); + } } mutex_unlock(&ctx->uring_lock); } -- 2.11.0