Re: [PATCH block/for-5.5-fixes] iocost: over-budget forced IOs should schedule async delay

[Jens Axboe]

On 12/16/19 2:34 PM, Tejun Heo wrote:
> When over-budget IOs are force-issued through root cgroup,
> iocg_kick_delay() adjusts the async delay accordingly but doesn't
> actually schedule async throttle for the issuing task.  This bug is
> pretty well masked because sooner or later the offending threads are
> gonna get directly throttled on regular IOs or have async delay
> scheduled by mem_cgroup_throttle_swaprate().
> 
> However, it can affect control quality on filesystem metadata heavy
> operations.  Let's fix it by invoking blkcg_schedule_throttle() when
> iocg_kick_delay() says async delay is needed.

Applied, thanks Tejun.

-- 
Jens Axboe