Re: [PATCH v4 12/12] blk-mq: Warn when attempting to run a hardware queue that is not mapped
From: Jens Axboe <axboe@kernel.dk>
Date: 2017-06-19 23:06:01
On 06/19/2017 04:08 PM, Bart Van Assche wrote:
quoted hunk ↗ jump to hunk
From: Bart Van Assche <redacted> A queue must be frozen while the mapped state of a hardware queue is changed. Additionally, any change of the mapped state is followed by a call to blk_mq_map_swqueue() (see also blk_mq_init_allocated_queue() and blk_mq_update_nr_hw_queues()). Since blk_mq_map_swqueue() does not map any unmapped hardware queue onto any software queue, no attempt will be made to run an unmapped hardware queue. Hence issue a warning upon attempts to run an unmapped hardware queue. Signed-off-by: Bart Van Assche <redacted> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <redacted> Cc: Ming Lei <redacted> --- block/blk-mq.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)diff --git a/block/blk-mq.c b/block/blk-mq.c index e7b0d69fdf65..c6218f32770d 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c@@ -1140,8 +1140,9 @@ static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async, unsigned long msecs) { - if (unlikely(blk_mq_hctx_stopped(hctx) || - !blk_mq_hw_queue_mapped(hctx))) + WARN_ON_ONCE(!blk_mq_hw_queue_mapped(hctx)); +
if (WARN_ON_ONCE(!blk_mq_hw_queue_mapped(hctx))) return; -- Jens Axboe