Messages in this thread | | | From | Dexuan Cui <> | Subject | RE: Random high CPU utilization in blk-mq with the none scheduler | Date | Mon, 13 Dec 2021 04:20:49 +0000 |
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> From: Ming Lei <ming.lei@redhat.com> > ... > Can you provide the following blk-mq debugfs log? > > (cd /sys/kernel/debug/block/dm-N && find . -type f -exec grep -aH . {} \;) > > (cd /sys/kernel/debug/block/sdN && find . -type f -exec grep -aH . {} \;) > > And it is enough to just collect log from one dm-mpath & one underlying iscsi > disk, > so we can understand basic blk-mq setting, such as nr_hw_queues, queue > depths, ... > > Thanks, > Ming
Attached. I collected the logs for all the dm-* and sd* devices against v5.16-rc4 with the 3 commits reverted: b22809092c70 ("block: replace always false argument with 'false'") ff1552232b36 ("blk-mq: don't issue request directly in case that current is to be blocked") dc5fc361d891 ("block: attempt direct issue of plug list")
v5.16-rc4 does not reproduce the issue, so I'm pretty sure b22809092c70 is the patch that resolves the excessive CPU usage. [unhandled content-type:application/x-zip-compressed] | |