Re: [Bug #15192] netperf ~50% regression with 2.6.33-rc1, bisectto 1b9508f

From: Mike Galbraith
Date: Sun Feb 21 2010 - 23:59:32 EST


On Sat, 2010-02-20 at 15:52 +0800, Lin Ming wrote:
> On Mon, 2010-02-01 at 16:04 +0800, Mike Galbraith wrote:
> > On Mon, 2010-02-01 at 01:22 +0100, Rafael J. Wysocki wrote:
> > > This message has been generated automatically as a part of a report
> > > of recent regressions.
> > >
> > > The following bug entry is on the current list of known regressions
> > > from 2.6.32. Please verify if it still should be listed and let me know
> > > (either way).
> >
> > Yes, it should remain open. We're currently waiting for some data from
> > Lin Ming. The regression itself isn't making much sense.. a kernel with
> > NEWIDLE disabled should show the same performance, but does not.
>
> (sorry for late response, I'm just back from vacation)
>
> We finally located this to a bug in mwait based C-state entry.
> Venki's patch has fixed it.
> http://patchwork.kernel.org/patch/78544/
>
> Venki, this is the original report,
> http://marc.info/?l=linux-kernel&m=126441481427331&w=4

Excellent, mystery solved. (adds acpi)

-Mike

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