4.18-stable review patch. If anyone has any objections, please let me know.
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From: Ilya Dryomov idryomov@gmail.com
commit 587562d0c7cd6861f4f90a2eb811cccb1a376f5f upstream.
trace_block_unplug() takes true for explicit unplugs and false for implicit unplugs. schedule() unplugs are implicit and should be reported as timer unplugs. While correct in the legacy code, this has been inverted in blk-mq since 4.11.
Cc: stable@vger.kernel.org Fixes: bd166ef183c2 ("blk-mq-sched: add framework for MQ capable IO schedulers") Reviewed-by: Omar Sandoval osandov@fb.com Signed-off-by: Ilya Dryomov idryomov@gmail.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- block/blk-mq.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1596,7 +1596,7 @@ void blk_mq_flush_plug_list(struct blk_p BUG_ON(!rq->q); if (rq->mq_ctx != this_ctx) { if (this_ctx) { - trace_block_unplug(this_q, depth, from_schedule); + trace_block_unplug(this_q, depth, !from_schedule); blk_mq_sched_insert_requests(this_q, this_ctx, &ctx_list, from_schedule); @@ -1616,7 +1616,7 @@ void blk_mq_flush_plug_list(struct blk_p * on 'ctx_list'. Do those. */ if (this_ctx) { - trace_block_unplug(this_q, depth, from_schedule); + trace_block_unplug(this_q, depth, !from_schedule); blk_mq_sched_insert_requests(this_q, this_ctx, &ctx_list, from_schedule); }