Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751481AbVJYHcg (ORCPT ); Tue, 25 Oct 2005 03:32:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751482AbVJYHcg (ORCPT ); Tue, 25 Oct 2005 03:32:36 -0400 Received: from mailgate-out2.mysql.com ([213.136.52.68]:26026 "EHLO mailgate.mysql.com") by vger.kernel.org with ESMTP id S1751481AbVJYHcg (ORCPT ); Tue, 25 Oct 2005 03:32:36 -0400 Message-ID: <435DE042.9060208@mysql.com> Date: Tue, 25 Oct 2005 09:35:30 +0200 From: Jonas Oreland User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.7.11) Gecko/20050915 X-Accept-Language: en-us, en MIME-Version: 1.0 To: john stultz , Andi Kleen CC: Jonas Oreland , lkml , Andrew Morton , discuss@x86-64.org Subject: x86-64: Syncing dualcore cpus TSCs References: <1127157404.3455.209.camel@cog.beaverton.ibm.com> <20051007122624.GA23606@tentacle.sectorb.msk.ru> <200510071431.47245.ak@suse.de> <20051008101153.GA1541@tentacle.sectorb.msk.ru> <1128967404.8195.419.camel@cog.beaverton.ibm.com> <20051010181216.GA21548@tentacle.sectorb.msk.ru> <434AB0BE.3080206@mysql.com> <20051011073532.GA29254@tentacle.sectorb.msk.ru> <434BE7E9.8000501@mysql.com> In-Reply-To: <434BE7E9.8000501@mysql.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 795 Lines: 19 Hi, This might be a very bad suggestion, but here it is: On dualcore cpus (amd64) the TSC will get out of sync when executing hlt instruction. booting with idle=poll, will make it never to execute hlt, hence TSC will be in sync. booting with notsc will make it use other time source...but this is slower (this is default after "[PATCH] x86-64: Fix bad assumption that dualcore cpus have synced TSCs") How about syncing TSC after hlt? If cost of syncing TSC's is smaller than cost of using other time source this might be an alternative. /Jonas - 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/