block/bfq_wf2q: correct weight to ioprio

YahuGao · axboe · commit bcd2be763252 · 2022-02-16T20:09:14.000-07:00
The return value is ioprio * BFQ_WEIGHT_CONVERSION_COEFF or 0. What we want is ioprio or 0. Correct this by changing the calculation. Signed-off-by: Yahu Gao <gaoyahu19@gmail.com> Acked-by: Paolo Valente <paolo.valente@linaro.org> Link: https://lore.kernel.org/r/20220107065859.25689-1-gaoyahu19@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c
@@ -519,7 +519,7 @@ unsigned short bfq_ioprio_to_weight(int ioprio)
 static unsigned short bfq_weight_to_ioprio(int weight)
 {
 	return max_t(int, 0,
-		     IOPRIO_NR_LEVELS * BFQ_WEIGHT_CONVERSION_COEFF - weight);
+		     IOPRIO_NR_LEVELS - weight / BFQ_WEIGHT_CONVERSION_COEFF);
 }
 
 static void bfq_get_entity(struct bfq_entity *entity)

Original file line number	Diff line number	Diff line change
`@@ -519,7 +519,7 @@ unsigned short bfq_ioprio_to_weight(int ioprio)`
`519`	`519`	`static unsigned short bfq_weight_to_ioprio(int weight)`
`520`	`520`	`{`
`521`	`521`	`return max_t(int, 0,`
`522`		`- IOPRIO_NR_LEVELS * BFQ_WEIGHT_CONVERSION_COEFF - weight);`
	`522`	`+ IOPRIO_NR_LEVELS - weight / BFQ_WEIGHT_CONVERSION_COEFF);`
`523`	`523`	`}`
`524`	`524`
`525`	`525`	`static void bfq_get_entity(struct bfq_entity *entity)`