[PATCH v3 14/14] bfq: optimize the calculation of bfq_weight_to_ioprio()
From: brookxu <hidden>
Date: 2021-03-25 06:59:21
Also in:
linux-block, lkml
Subsystem:
bfq i/o scheduler, block layer, the rest · Maintainers:
Yu Kuai, Jens Axboe, Linus Torvalds
From: Chunguang Xu <redacted> The value range of ioprio is [0, 7], but the result of bfq_weight_to_ioprio() may exceed this range, so simple optimization is required. Signed-off-by: Chunguang Xu <redacted> --- block/bfq-wf2q.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c
index b477a9b..1b91c8b 100644
--- a/block/bfq-wf2q.c
+++ b/block/bfq-wf2q.c@@ -586,8 +586,9 @@ unsigned short bfq_ioprio_to_weight(int ioprio) */ static unsigned short bfq_weight_to_ioprio(int weight) { - return max_t(int, 0, - IOPRIO_BE_NR * BFQ_WEIGHT_CONVERSION_COEFF - weight); + int ioprio = IOPRIO_BE_NR - weight / BFQ_WEIGHT_CONVERSION_COEFF; + + return ioprio < 0 ? 0 : min_t(int, ioprio, IOPRIO_BE_NR - 1); } static void bfq_get_entity(struct bfq_entity *entity)
--
1.8.3.1