From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kemeng Shi Subject: [PATCH v2 2/3] block: Correct comment for scale_cookie_change Date: Tue, 18 Oct 2022 19:12:39 +0800 Message-ID: <20221018111240.22612-3-shikemeng@huawei.com> References: <20221018111240.22612-1-shikemeng@huawei.com> Mime-Version: 1.0 Return-path: In-Reply-To: <20221018111240.22612-1-shikemeng-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, josef-DigfWCa+lFGyeJad7bwFQA@public.gmane.org, axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, shikemeng-hv44wF8Li93QT0dZR+AlfA@public.gmane.org Default queue depth of iolatency_grp is unlimited, so we scale down quickly(once by half) in scale_cookie_change. Remove the "subtract 1/16th" part which is not the truth and add the actual way we scale down. Signed-off-by: Kemeng Shi --- block/blk-iolatency.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c index b24d7b788ba3..2c574f98c8d1 100644 --- a/block/blk-iolatency.c +++ b/block/blk-iolatency.c @@ -364,9 +364,11 @@ static void scale_cookie_change(struct blk_iolatency *blkiolat, } /* - * Change the queue depth of the iolatency_grp. We add/subtract 1/16th of the + * Change the queue depth of the iolatency_grp. We add 1/16th of the * queue depth at a time so we don't get wild swings and hopefully dial in to - * fairer distribution of the overall queue depth. + * fairer distribution of the overall queue depth. We halve the queue depth + * at a time so we can scale down queue depth quickly from default unlimited + * to target. */ static void scale_change(struct iolatency_grp *iolat, bool up) { -- 2.30.0