Re: [PATCH V4 07/15] blk-throttle: make throtl_slice tunable

From: Tejun Heo
Date: Tue Nov 22 2016 - 16:27:22 EST


Hello,

On Mon, Nov 14, 2016 at 02:22:14PM -0800, Shaohua Li wrote:
> throtl_slice is important for blk-throttling. A lot of stuffes depend on
> it, for example, throughput measurement. It has 100ms default value,
> which is not appropriate for all disks. For example, for SSD we might
> use a smaller value to make the throughput smoother. This patch makes it
> tunable.

It bothers me a bit because time slice doesn't mean anything inherent
to throttling. It really is an implementation detail - throttling can
be implemented at per-operation level without time slice involved at
all. It's okay to expose the knob if necessary but the meaning of the
knob is almost completely arbitrary to users (as it has no inherent
meaning).

Thanks.

--
tejun