Messages in this thread | | | From | Joel Fernandes <> | Date | Wed, 22 Mar 2017 12:19:17 -0700 | Subject | Re: [PATCH] sched: fair: Improve PELT decay_load calculation comments |
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Hi Peter,
On Wed, Mar 22, 2017 at 10:02 AM, Peter Zijlstra <peterz@infradead.org> wrote: > On Wed, Mar 22, 2017 at 09:35:43AM -0700, Joel Fernandes wrote: >> On Wed, Mar 22, 2017 at 7:16 AM, Peter Zijlstra <peterz@infradead.org> wrote: >> > On Fri, Mar 10, 2017 at 12:23:41PM -0800, Joel Fernandes wrote: >> >> The PELT decay_load comments are a bit confusing, first of all >> >> the 1/2^N should be (1/2)^N so that the reader doesn't get confused. >> > >> > I'm thinking you're confused. They're identical. >> > >> > (1/2)^N = (2^-1)^N = 2^-N = 1/2^N >> >> They are identical I know, but I meant by enclosing the 1/2 in >> brackets, it is more clear that we multiply by 1/2 N times to the >> first time reader - for the reason that we'd like to reduce the PELT >> calculated load by 1/2 N times. > > Must be me then, because I've never been confused about that. Esp. so > since the first part: y^p = 1/2, explicitly mentions half. So its clear > from the factorization that half is meant.
Yes that's true.
>> >> Secondly, the y^N splitting into a 2-part decay factor deserves >> >> a better explanation. This patch improves the comments. >> > >> > I find its actually harder to read. >> >> Oh, which part? Can you help improve it? Maybe I didn't word something >> correctly? > > I think the fact that there's now words actually makes it worse. > > The equation very concisely shows what we do. I don't see why we need > extra words there to obscure things.
Ok, I agree with you and will kill this patch then. Thanks for the review.
Regards, Joel
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