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authorKemeng Shi <shikemeng@huawei.com>2022-10-18 14:12:39 +0300
committerJens Axboe <axboe@kernel.dk>2022-11-01 18:12:24 +0300
commit6891f968985f0569eaf56430518895b3c2885da1 (patch)
tree4e954cb97720333e7f869a1fe1ef9d32888b3063 /block/blk-iolatency.c
parentdb5896e9cf93f119c0b181c5e6b473d8bf0302e5 (diff)
downloadlinux-6891f968985f0569eaf56430518895b3c2885da1.tar.xz
block: Correct comment for scale_cookie_change
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 <shikemeng@huawei.com> Link: https://lore.kernel.org/r/20221018111240.22612-3-shikemeng@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-iolatency.c')
-rw-r--r--block/blk-iolatency.c6
1 files 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)
{