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 <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 332008f..6e31698 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);
}