From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dominik Brodowski Subject: Re: SMP status? Date: Tue, 22 Jul 2003 14:04:22 +0200 Sender: cpufreq-admin@www.linux.org.uk Message-ID: <20030722120422.GC1160@brodo.de> References: Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: Errors-To: cpufreq-admin@www.linux.org.uk List-Unsubscribe: , List-Id: List-Post: List-Help: List-Subscribe: , List-Archive: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: John Clemens Cc: cpufreq@www.linux.org.uk On Mon, Jul 21, 2003 at 01:06:05AM -0400, John Clemens wrote: > > Out of curiousity, has anyone thought about what it would take get SMP > support into cpufreq? I'm thinking about servers... It's already done. The generic cpufreq core is perfectly SMP-capable, the x86 timing updates [in arch/i386/kernel/timers/timer_tsc.c] is SMP-capable, the /proc/sys/, /proc and /sys/devices interfaces are SMP-capable. However, it's more a question of which CPUs support frequency and voltage scaling. There's no "speedstep" for server-grade processors yet, though AMD is reportedly thinking of including PowerNow in future releases of their AMD64 processors. So, on x86 only the throttling-driver "p4-clockmod" does provide SMP [and Hyperthreading!] support. On other architectures cpufreq + SMP is more widely available, e.g. on sparc64. > how big of a rats nest is this, as bad as i think it is? It seems to work :-) Dominik