On 04/06/2019 09:54 AM, Shenghui Wang wrote:
> Set plug->rq_count 0 earlier can skip possible sort.
> Move the 0-value set after sort.
The same fix already exists at:
https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git/commit/?h=for-linus&id=bcc816dfe51ab86ca94663c7b225f2d6eb0fddb9
Dongli Zhang
>
> Signed-off-by: Shenghui Wang <[email protected]>
> ---
> block/blk-mq.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index f3b0d33bdf88..e5d32f186e81 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -1711,10 +1711,10 @@ void blk_mq_flush_plug_list(struct blk_plug *plug,
> bool from_schedule)
> unsigned int depth;
>
> list_splice_init(&plug->mq_list, &list);
> - plug->rq_count = 0;
>
> if (plug->rq_count > 2 && plug->multiple_queues)
> list_sort(NULL, &list, plug_rq_cmp);
> + plug->rq_count = 0;
>
> this_q = NULL;
> this_hctx = NULL;
>
