Re: [PATCH] init: Don't decrease loops_per_jiffy when a CPU comes up

From: Doug Anderson
Date: Tue May 13 2014 - 18:54:29 EST


Paul,

On Fri, May 9, 2014 at 9:03 AM, Paul Gortmaker
<paul.gortmaker@xxxxxxxxxxxxx> wrote:
> On 14-05-07 07:50 PM, Doug Anderson wrote:
>> The loops_per_jiffy count continues to be updated as each CPU is
>> brought up. This causes problems when we've got an HMP system and
>> different CPUs have different loops per jiffy. On exynos 542x
>> systems, for instance, the A7s will have significantly lower loops per
>> jiffy than their big brothers.
>
> Based on the other discussion for the ARM variant of this, I'm
> assuming this also becomes a WFC issue. And if not, then it
> probably should go by John or similar ; getmaintainers is just
> being dumb in spitting my name out, since I only made one
> trivial change to this file a year ago or similar.

I think this change could still make sense. The ARM discussion is
about dealing with the scaling that the ARM code does, but it really
is a separate concept.

In general it seems like at least a warning is in order if
loops_per_jiffy changes significantly from CPU to CPU.
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