From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 7 Jul 2008 17:31:05 -0400 From: Dave Jones To: Arnd Bergmann Subject: Re: powerpc/cell/cpufreq: add spu aware cpufreq governor Message-ID: <20080707213105.GD4997@codemonkey.org.uk> References: <200807071702.31240.arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <200807071702.31240.arnd@arndb.de> Cc: Stephen Rothwell , cpufreq@lists.linux.org.uk, linuxppc-dev@ozlabs.org, Jeremy Kerr , cbe-oss-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Jul 07, 2008 at 05:02:30PM +0200, Arnd Bergmann wrote: > From: Christian Krafft > > This patch adds a cpufreq governor that takes the number of running spus > into account. It's very similar to the ondemand governor, but not as complex. > Instead of hacking spu load into the ondemand governor it might be easier to > have cpufreq accepting multiple governors per cpu in future. > Don't know if this is the right way, but it would keep the governors simple. > > Signed-off-by: Christian Krafft > Signed-off-by: Arnd Bergmann > --- > > Dave or other cpufreq people, can you take a look at this > and add an Acked-by when you're happy? It looks ok on a quick look through. I'm wondering about the multiple governors thing though. This came up at last years power management summit, but no-one has mentioned it since. I think it's possible we want to look at things like this in the future, and not just for cell. I keep hearing mumblings about future generations of x86's having dedicated coprocessors for certain tasks that may benefit from the same thing. > We have one prerequisite patch in the powerpc code (in spufs), > so should it get merged through powerpc.git? That's fine with me. Conflicts should be minimal if any at all, I've got nothing queued up which touches that part of Kconfig/Makefile One question I do have though, is how userspace scripts are supposed to know they're to echo cbe_spu_governor into the relevant parts of sysfs. I've not used anything with a cell. Do they expose the SPUs as regular CPUs, or do they show up in a different part of the tree? Dave -- http://www.codemonkey.org.uk