Re: [PATCH 2/5] writeback: dirty position control

From: Wu Fengguang
Date: Fri Aug 26 2011 - 08:21:11 EST


On Fri, Aug 26, 2011 at 08:11:50PM +0800, Peter Zijlstra wrote:
> On Fri, 2011-08-26 at 19:26 +0800, Wu Fengguang wrote:
> > Now I get 3 figures. Test case is: run 1 dd write task for 300s, with
> > a "disturber" dd read task during roughly 120-130s.
>
> Ah, but ideally the disturber task should run in bursts of 100ms
> (<feedback period), otherwise your N is indeed mostly constant.

Ah yeah, the disturber task should be a dd writer! Then we get

- 120s: N=1 => N=2
- 130s: N=2 => N=1

I'll try it right away.

Thanks,
Fengguang
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