Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754633AbYCaCSc (ORCPT ); Sun, 30 Mar 2008 22:18:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750923AbYCaCSZ (ORCPT ); Sun, 30 Mar 2008 22:18:25 -0400 Received: from netops-testserver-3-out.sgi.com ([192.48.171.28]:60672 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750775AbYCaCSY (ORCPT ); Sun, 30 Mar 2008 22:18:24 -0400 Date: Sun, 30 Mar 2008 21:18:21 -0500 From: Jack Steiner To: Yinghai Lu Cc: Andi Kleen , Ingo Molnar , tglx@linutronix.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [RFC 8/8] x86_64: Support for new UV apic Message-ID: <20080331021821.GC20619@sgi.com> References: <20080324182122.GA28327@sgi.com> <87abknhzhd.fsf@basil.nowhere.org> <20080325175657.GA6262@sgi.com> <20080326073823.GD3442@elte.hu> <86802c440803301323q5c4bd4f4k1f9bdc1d6b1a0a7b@mail.gmail.com> <20080330210356.GA13383@sgi.com> <20080330211848.GA29105@one.firstfloor.org> <86802c440803301629g6d1b896o27e12ef3c84ded2c@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <86802c440803301629g6d1b896o27e12ef3c84ded2c@mail.gmail.com> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 832 Lines: 24 > > if the calling path like GET_APIC_ID is keeping checking if it is UV > box after boot time, that may not good. > > don't need make other hundreds of machine keep running the code only > for several big box all the time. > > YH I added trace code to see how often GET_APIC_ID() is called. For my 8p AMD box, the function is called 6 times per cpu during boot. I have not seen any other calls to the function after early boot although I'm they occur under some circumstances. Can you think of a workload where the frequency of calls is high enough to be significant?? --- jack -- 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/