On 10/5/23 23:36, Kanchan Joshi wrote:
On Thu, Oct 05, 2023 at 12:40:48PM -0700, Bart Van Assche wrote:
A later patch will store the data lifetime in the bio->bi_ioprio member
before the blk-ioprio policy is applied. Make sure that this policy
doesn't
clear more bits than necessary.
Cc: Damien Le Moal <dlemoal@xxxxxxxxxx>
Cc: Niklas Cassel <niklas.cassel@xxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
block/blk-ioprio.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/block/blk-ioprio.c b/block/blk-ioprio.c
index 4051fada01f1..2db86f153b6d 100644
--- a/block/blk-ioprio.c
+++ b/block/blk-ioprio.c
@@ -202,7 +202,8 @@ void blkcg_set_ioprio(struct bio *bio)
* to achieve this.
*/
if (IOPRIO_PRIO_CLASS(bio->bi_ioprio) != IOPRIO_CLASS_RT)
- bio->bi_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_RT, 4);
+ ioprio_set_class_and_level(&bio->bi_ioprio,
+ IOPRIO_PRIO_VALUE(IOPRIO_CLASS_RT, 4));
return;
}
@@ -213,10 +214,10 @@ void blkcg_set_ioprio(struct bio *bio)
* If the bio I/O priority equals IOPRIO_CLASS_NONE, the cgroup I/O
* priority is assigned to the bio.
*/
- prio = max_t(u16, bio->bi_ioprio,
+ prio = max_t(u16, bio->bi_ioprio & IOPRIO_CLASS_LEVEL_MASK,
IOPRIO_PRIO_VALUE(blkcg->prio_policy, 0));
All 9 bits (including CDL) are not taking part in this decision making
now. Maybe you want to exclude only lifetime bits.
- if (prio > bio->bi_ioprio)
- bio->bi_ioprio = prio;
+ if (prio > (bio->bi_ioprio & IOPRIO_CLASS_LEVEL_MASK))
+ ioprio_set_class_and_level(&bio->bi_ioprio, prio);
Same as above.
Hi Kanchan,
It is intentional that the CDL bits are left out from these decisions.
I think the decisions made in this policy should be based on the I/O
priority class and level only and not on the CDL value.
Thanks,
Bart.
