block: Introduce IOPRIO_NR_LEVELS

The BFQ scheduler and ioprio_check_cap() both assume that the RT
priority class (IOPRIO_CLASS_RT) can have up to 8 different priority
levels, similarly to the BE class (IOPRIO_CLASS_iBE). This is
controlled using the IOPRIO_BE_NR macro , which is badly named as the
number of levels also applies to the RT class.

Introduce the class independent IOPRIO_NR_LEVELS macro, defined to 8,
to make things clear. Keep the old IOPRIO_BE_NR macro definition as an
alias for IOPRIO_NR_LEVELS.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Link: https://lore.kernel.org/r/20210811033702.368488-6-damien.lemoal@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Damien Le Moal
2021-08-11 12:37:01 +09:00
committed by Jens Axboe
parent ba05200fcc
commit 202bc942c5
6 changed files with 14 additions and 14 deletions

View File

@@ -505,7 +505,7 @@ static void bfq_active_insert(struct bfq_service_tree *st,
*/
unsigned short bfq_ioprio_to_weight(int ioprio)
{
return (IOPRIO_BE_NR - ioprio) * BFQ_WEIGHT_CONVERSION_COEFF;
return (IOPRIO_NR_LEVELS - ioprio) * BFQ_WEIGHT_CONVERSION_COEFF;
}
/**
@@ -514,12 +514,12 @@ unsigned short bfq_ioprio_to_weight(int ioprio)
*
* To preserve as much as possible the old only-ioprio user interface,
* 0 is used as an escape ioprio value for weights (numerically) equal or
* larger than IOPRIO_BE_NR * BFQ_WEIGHT_CONVERSION_COEFF.
* larger than IOPRIO_NR_LEVELS * BFQ_WEIGHT_CONVERSION_COEFF.
*/
static unsigned short bfq_weight_to_ioprio(int weight)
{
return max_t(int, 0,
IOPRIO_BE_NR * BFQ_WEIGHT_CONVERSION_COEFF - weight);
IOPRIO_NR_LEVELS * BFQ_WEIGHT_CONVERSION_COEFF - weight);
}
static void bfq_get_entity(struct bfq_entity *entity)