Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753046Ab0FCNEz (ORCPT ); Thu, 3 Jun 2010 09:04:55 -0400 Received: from e35.co.us.ibm.com ([32.97.110.153]:57051 "EHLO e35.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752179Ab0FCNEy (ORCPT ); Thu, 3 Jun 2010 09:04:54 -0400 Date: Thu, 3 Jun 2010 18:34:50 +0530 From: Srivatsa Vaddagiri To: Nick Piggin Cc: Avi Kivity , Andi Kleen , Gleb Natapov , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, hpa@zytor.com, mingo@elte.hu, tglx@linutronix.de, mtosatti@redhat.com Subject: Re: [PATCH] use unfair spinlock when running on hypervisor. Message-ID: <20100603130450.GA26607@linux.vnet.ibm.com> Reply-To: vatsa@in.ibm.com References: <4C053ACC.5020708@redhat.com> <20100601172730.GB11880@basil.fritz.box> <4C05C722.1010804@redhat.com> <20100602085055.GA14221@basil.fritz.box> <4C061DAB.6000804@redhat.com> <20100603042051.GA5953@linux.vnet.ibm.com> <20100603103855.GG6822@laptop> <20100603120450.GH4035@linux.vnet.ibm.com> <20100603123832.GL6822@laptop> <20100603125821.GJ4035@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100603125821.GJ4035@linux.vnet.ibm.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 614 Lines: 14 On Thu, Jun 03, 2010 at 06:28:21PM +0530, Srivatsa Vaddagiri wrote: > Ok got it - although that approach is not advisable in some cases for ex: when > the lock holder vcpu and lock acquired vcpu are scheduled on the same pcpu by > the hypervisor (which was experimented with in [1] where they foud a huge hit in > perf). 1. http://lkml.org/lkml/2010/4/13/464 - vatsa -- 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/