Re: [PATCH v2] blk-throttle: simplify logic by token bucket algorithm

[Vivek Goyal <vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On Mon, Oct 14, 2013 at 09:36:20AM -0400, Tejun Heo wrote:
> Hello,
> 
> On Mon, Oct 14, 2013 at 05:09:17PM +0800, Hong Zhiguo wrote:
> > From: Hong Zhiguo <zhiguohong-1Nz4purKYjRBDgjK7y7TUQ@public.gmane.org>
> > 
> > Token bucket algorithm(http://en.wikipedia.org/wiki/Token_bucket)
> > is very simple and widely used for rate limiting and shaping.
> > It's well suitable for blk-throttle. And it natually works for
> > hierarchical cgroups. So I took it to replace the original time
> > _slicing_|_trimming_|_extending_ logic.
> > 
> > The advantage is simplicity, reliability and less fluctuation.
> > 
> > About 300 lines of code for time-slicing is replaced with 60 lines of
> > code for token bucket in blk-throttle.c.
> > 
> > I've tested this patch by fio with rw=randread, rw=randrw. It
> > behaves almost the same with original time-slicing implementation,
> > and with more accuracy.
> 
> Yes, this definitely is the direction we wanna take it.  I'll wait for
> Vivek to chime in but have you also tested hierarchical setup?

Hi Tejun,

I will have a look at it either today or tomorrow.

Thanks
Vivek