Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268484AbUILGKQ (ORCPT ); Sun, 12 Sep 2004 02:10:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268486AbUILGKQ (ORCPT ); Sun, 12 Sep 2004 02:10:16 -0400 Received: from ozlabs.org ([203.10.76.45]:6537 "EHLO ozlabs.org") by vger.kernel.org with ESMTP id S268484AbUILGKM (ORCPT ); Sun, 12 Sep 2004 02:10:12 -0400 Date: Sun, 12 Sep 2004 16:09:04 +1000 From: Anton Blanchard To: Nick Piggin Cc: Zwane Mwaikambo , Andrew Morton , torvalds@osdl.org, paulus@samba.org, linux-kernel@vger.kernel.org, jun.nakajima@intel.com, ak@suse.de, mingo@elte.hu Subject: Re: [PATCH] Yielding processor resources during lock contention Message-ID: <20040912060904.GJ32755@krispykreme> References: <20040911220003.0e9061ad.akpm@osdl.org> <4143D16F.30500@yahoo.com.au> <4143D491.6070006@yahoo.com.au> <4143D855.9070005@yahoo.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4143D855.9070005@yahoo.com.au> User-Agent: Mutt/1.5.6+20040818i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 964 Lines: 25 > OK that sounds alight. > > If it is a "I'm going to be spinning for ages, so schedule me off *now*" > then I think it is wrong... but if it just allows you to keep the hypervisor > preemption turned on, then fine. The hypervisor can preempt us anywhere but we can give it clues so it tends to preempt us at better times. Within a few instructions the hypervisor should be able to answer the big question: is the cpu Im waiting for currently scheduled on another cpu. If it is then it might be best for the hypervisor to leave us alone. If it isnt then the spin time will most likely be dominated by how long it takes to get that cpu scheduled again and the hypervisor should make an effort to schedule it. Anton - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/