Re: [Bug #11308] tbench regression on each kernel release from 2.6.22-> 2.6.28

From: Linus Torvalds
Date: Mon Nov 17 2008 - 14:56:29 EST




On Mon, 17 Nov 2008, David Miller wrote:
>
> Again, do a non-NMI profile and the top (at least for me)
> looks like this:

Can _you_ please do a NMI profile and see what your real problem is?

I can't imagine that Niagara (or whatever) is so weak that it can't do
NMI's.

The fact is, David, that Ingo just posted a profile that was _better_ than
anything you have ever posted, and it doesn't show what you complain
about. So he's not seeing it. Asking him to do a _stupid_ profile is just
that: stupid.

So try to figure out why his (better) profile doesn't match your
(inferior) one, instead of asking him to do stupid things. It's some
difference in architectures, likely: maybe the sparc timekeeping is crap,
maybe it's a cache issue and sparc caches are crap, maybe it's something
where Niagara (is it niagara) has some oddness that shows up because it
has that odd four-threads+four-cores or whatever.

Linus
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