From 80c18e4ac20c9cde420cb3ffab48c936147cf07d Mon Sep 17 00:00:00 2001
From: Pavel Begunkov <asml.silence@gmail.com>
Date: Thu, 7 Jan 2021 03:15:41 +0000
Subject: [PATCH] io_uring: trigger eventfd for IOPOLL
Make sure io_iopoll_complete() tries to wake up eventfd, which currently
is skipped together with io_cqring_ev_posted() for non-SQPOLL IOPOLL.
Add an iopoll version of io_cqring_ev_posted(), duplicates a bit of
code, but they actually use different sets of wait queues may be for
better.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
fs/io_uring.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 27a8c226abf8c..91e517ad1421c 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1713,6 +1713,16 @@ static void io_cqring_ev_posted(struct io_ring_ctx *ctx)
eventfd_signal(ctx->cq_ev_fd, 1);
}
+static void io_cqring_ev_posted_iopoll(struct io_ring_ctx *ctx)
+{
+ if (ctx->flags & IORING_SETUP_SQPOLL) {
+ if (waitqueue_active(&ctx->wait))
+ wake_up(&ctx->wait);
+ }
+ if (io_should_trigger_evfd(ctx))
+ eventfd_signal(ctx->cq_ev_fd, 1);
+}
+
/* Returns true if there are no backlogged entries after the flush */
static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force,
struct task_struct *tsk,
@@ -2428,8 +2438,7 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
}
io_commit_cqring(ctx);
- if (ctx->flags & IORING_SETUP_SQPOLL)
- io_cqring_ev_posted(ctx);
+ io_cqring_ev_posted_iopoll(ctx);
io_req_free_batch_finish(ctx, &rb);
if (!list_empty(&again))
--
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