Re: [PATCH v2] kyber: introduce kyber_depth_updated()

From: Jens Axboe
Date: Mon Feb 22 2021 - 14:39:19 EST


On 2/5/21 2:13 AM, Yang Yang wrote:
> Hang occurs when user changes the scheduler queue depth, by writing to
> the 'nr_requests' sysfs file of that device.
>
> The details of the environment that we found the problem are as follows:
> an eMMC block device
> total driver tags: 16
> default queue_depth: 32
> kqd->async_depth initialized in kyber_init_sched() with queue_depth=32
>
> Then we change queue_depth to 256, by writing to the 'nr_requests' sysfs
> file. But kqd->async_depth don't be updated after queue_depth changes.
> Now the value of async depth is too small for queue_depth=256, this may
> cause hang.
>
> This patch introduces kyber_depth_updated(), so that kyber can update
> async depth when queue depth changes.

Applied, thanks.

--
Jens Axboe