Re: very low IOPS due to "block: reduce kblockd_mod_delayed_work_on() CPU consumption"

[Jens Axboe]

On 12/18/21 11:57 AM, Alex Xu (Hello71) wrote:
> Hi,
> 
> I recently noticed that between 6441998e2e and 9eaa88c703, I/O became 
> much slower on my machine using ext4 on dm-crypt on NVMe with bfq 
> scheduler. Checking iostat during heavy usage (find / -xdev and fstrim 
> -v /), maximum IOPS had fallen from ~10000 to ~100. Reverting cb2ac2912a 
> ("block: reduce kblockd_mod_delayed_work_on() CPU consumption") resolves 
> the issue.

Hmm interesting. I'll try and see if I can reproduce this and come up
with a fix.

-- 
Jens Axboe