From: Ryan Arnold <rsa@us.ibm.com>
To: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Will Schmidt <will_schmidt@vnet.ibm.com>,
Steven Munroe <sjmunroe@us.ibm.com>,
linuxppc-dev@ozlabs.org
Subject: Re: [RFC] Moving toward smarter disabling of FPRs, VRs, and VSRs in the MSR
Date: Sat, 14 Mar 2009 09:58:59 -0500 [thread overview]
Message-ID: <1237042739.8874.3.camel@localhost.localdomain> (raw)
In-Reply-To: <FFBC9638-D064-43F9-B764-243739289710@kernel.crashing.org>
On Sat, 2009-03-14 at 14:49 +0100, Segher Boessenkool wrote:
> > Another option might be simply to say that if an app has used FP,
> > VMX or
> > VSX -once-, then it's likely to do it again and just keep re-enabling
> > it :-)
> >
> > I'm serious here, do we know that many cases where these things are
> > used
> > seldomly once in a while ?
>
> For FP, I believe many apps use it only sporadically. But for VMX
> and VSX,
> yeah, it might well be optimal to keep it enabled all the time. Someone
> should do some profiling...
We can do some VMX testing on existing POWER6 machines. The VSX
instruction set hasn't been fully implemented in GCC yet so we'll need
to wait a bit for that. Does anyone have an idea for a good VMX/Altivec
benchmark?
Ryan
next prev parent reply other threads:[~2009-03-14 14:59 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-13 20:23 [RFC] Moving toward smarter disabling of FPRs, VRs, and VSRs in the MSR Ryan Arnold
2009-03-13 21:15 ` Kumar Gala
2009-03-13 22:45 ` Benjamin Herrenschmidt
2009-03-13 23:52 ` Josh Boyer
2009-03-14 2:31 ` Ryan Arnold
2009-03-14 3:22 ` Benjamin Herrenschmidt
2009-03-14 13:55 ` Segher Boessenkool
2009-03-14 13:49 ` Segher Boessenkool
2009-03-14 14:58 ` Ryan Arnold [this message]
2009-03-16 0:49 ` Benjamin Herrenschmidt
2009-03-16 6:43 ` Michael Neuling
2009-03-16 10:52 ` Gabriel Paubert
2009-03-14 8:20 ` Michael Neuling
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