Re: [PATCH] x86: eliminate redundant/contradicting cache line size config options

Arjan van de Ven
2009-11-23T14:50:16Z

On Mon, 23 Nov 2009 09:34:59 +0100
Ingo Molnar <mingo@elte.hu> wrote:

>
> * Arjan van de Ven <arjan@infradead.org> wrote:
>
> > On Thu, 19 Nov 2009 09:13:07 +0100
> > Nick Piggin <npiggin@suse.de> wrote:
> > >
> > > My other point was just this, but I don't care too much. But it is
> > > worded pretty negatively. The key here is that increasing the
> > > value too large tends to only cost a very small amount of size
> > > (and no increase in cacheline foot print, only RAM).
> >
> > 128 has a pretty significant impact on TPC-C benchmarks.....
> > it was the top issue until mainline fixed it to default to 64
>
> Mind sending a patch that sets the default to 64 on NUMA too?
>
> P4 based NUMA boxes are ... a bad memory to be forgotten.

this patch adds a regression. Linux defaulted to 64 since.. march or so.

now we go back to the old setting; Nick should fix that. Or at least
extremely document and justify this change....

--
Arjan van de Ven Intel Open Source Technology Centre
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