* Mel Gorman <mgor...@suse.de> wrote:
> On Thu, Dec 19, 2013 at 05:49:25PM +0100, Ingo Molnar wrote:
> >
> > * Mel Gorman <mgor...@suse.de> wrote:
> >
> > > [...]
> > >
> > > Because we lack data on TLB range flush distributions I think we
> > > should still go with the conservative choice for the TLB flush
> > > shift. The worst case is really bad here and it's painfully obvious
> > > on ebizzy.
> >
> > So I'm obviously much in favor of this - I'd in fact suggest
> > making the conservative choice on _all_ CPU models that have
> > aggressive TLB range values right now, because frankly the testing
> > used to pick those values does not look all that convincing to me.
>
> I think the choices there are already reasonably conservative. I'd
> be reluctant to support merging a patch that made a choice on all
> CPU models without having access to the machines to run tests on. I
> don't see the Intel people volunteering to do the necessary testing.
So based on this thread I lost confidence in test results on all CPU
models but the one you tested.
I see two workable options right now:
- We turn the feature off on all other CPU models, until someone
measures and tunes them reliably.
or
- We make all tunings that are more aggressive than yours to match
yours. In the future people can measure and argue for more
aggressive tunings.
Thanks,
Ingo
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