]> www.infradead.org Git - users/hch/block.git/commit
block, bfq: forbid stable merging of queues associated with different actuators
authorPaolo Valente <paolo.valente@linaro.org>
Tue, 3 Jan 2023 14:54:57 +0000 (15:54 +0100)
committerJens Axboe <axboe@kernel.dk>
Mon, 16 Jan 2023 13:45:09 +0000 (06:45 -0700)
commit615b51f2a7ec9a142c13dc6afab4f371d4ed0fb5
treeafffd9a9b64bc967ae3e97d0b25081499bf93bb5
parent51ec2387623a63268edb9da1da6369af47cfd5f0
block, bfq: forbid stable merging of queues associated with different actuators

If queues associated with different actuators are merged, then control
is lost on each actuator. Therefore some actuator may be
underutilized, and throughput may decrease. This problem cannot occur
with basic queue merging, because the latter is triggered by spatial
locality, and sectors for different actuators are not close to each
other. Yet it may happen with stable merging. To address this issue,
this commit prevents stable merging from occurring among queues
associated with different actuators.

Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20230103145503.71712-3-paolo.valente@linaro.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
block/bfq-iosched.c