blk-mq: skip hybrid polling if iopoll doesn't spin (f6f371f7) · Commits · 戴 / test

If blk_poll() is not going to spin (i.e. @spin=false), it also must not sleep in hybrid polling, otherwise it might be pretty suprising for users trying to do a quick check and expecting no-wait behaviour. Signed-off-by:

Pavel Begunkov <asml.silence@gmail.com> Signed-off-by:

Jens Axboe <axboe@kernel.dk>

block/blk-mq.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -3865,9 +3865,10 @@ int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin)
		* the state. Like for the other success return cases, the
		* caller is responsible for checking if the IO completed. If
		* the IO isn't complete, we'll get called again and will go
		* straight to the busy poll loop.
		* straight to the busy poll loop. If specified not to spin,
		* we also should not sleep.
		*/
		if (blk_mq_poll_hybrid(q, hctx, cookie))
		if (spin && blk_mq_poll_hybrid(q, hctx, cookie))
		return 1;

		hctx->poll_considered++;

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