Re: [PATCH 16/35] writeback: increase min pause time on concurrentdirtiers

[Peter Zijlstra]

On Tue, 2010-12-14 at 13:42 -0500, Valdis.Kletnieks@xxxxxx wrote:
> On Tue, 14 Dec 2010 14:51:33 +0800, Wu Fengguang said:
> 
> > > > +	/* (N * 10ms) on 2^N concurrent tasks */
> > > > +	t = (hi - lo) * (10 * HZ) / 1024;
> > > 
> > > Either I need more caffeine, or the comment doesn't match the code
> > > if HZ != 1000?
> > 
> > The "ms" in the comment may be confusing, but the pause time (t) is
> > measured in jiffies :)  Hope the below patch helps.
> 
> No, I meant that 10 * HZ evaluates to different numbers depending what
> the CONFIG_HZ parameter is set to - 100, 250, 1000, or some other
> custom value.  Does this code behave correctly on a CONFIG_HZ=100 kernel?

10*HZ = 10 seconds
(10*HZ) / 1024 ~= 10 milliseconds
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