From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: [PATCH] git gc: Speed it up by 18% via faster hash comparisons Date: Thu, 28 Apr 2011 11:38:37 +0200 Message-ID: <20110428093837.GA15847@elte.hu> References: <20110427225114.GA16765@elte.hu> <20110428091110.GA14431@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: git@vger.kernel.org, "H. Peter Anvin" , Thomas Gleixner , Peter Zijlstra , Arnaldo Carvalho de Melo , =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , Pekka Enberg To: Dmitry Potapov X-From: git-owner@vger.kernel.org Thu Apr 28 11:39:12 2011 Return-path: Envelope-to: gcvg-git-2@lo.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1QFNgl-0007sY-3P for gcvg-git-2@lo.gmane.org; Thu, 28 Apr 2011 11:39:11 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757942Ab1D1Ji7 (ORCPT ); Thu, 28 Apr 2011 05:38:59 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:58528 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751131Ab1D1Ji6 (ORCPT ); Thu, 28 Apr 2011 05:38:58 -0400 Received: from elvis.elte.hu ([157.181.1.14]) by mx3.mail.elte.hu with esmtp (Exim) id 1QFNgF-0002Mu-6V from ; Thu, 28 Apr 2011 11:38:44 +0200 Received: by elvis.elte.hu (Postfix, from userid 1004) id 47D0D3E236B; Thu, 28 Apr 2011 11:38:33 +0200 (CEST) Content-Disposition: inline In-Reply-To: <20110428091110.GA14431@elte.hu> User-Agent: Mutt/1.5.20 (2009-08-17) Received-SPF: neutral (mx3: 157.181.1.14 is neither permitted nor denied by domain of elte.hu) client-ip=157.181.1.14; envelope-from=mingo@elte.hu; helo=elvis.elte.hu; X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: * Ingo Molnar wrote: > > Another thing is that so far this optimization was only with > > GCC, and we do not know whether it helps or harms to compilers. > > So, maybe placing this code under 'ifdef __GNUC__' makes more > > sense than pushing this change on other compilers too. > > Well, given that 90%+ of Git development is done with GCC (and probably the > user share is similarly high as well): > > aldebaran:~/git> git log --pretty=oneline -i --grep gcc | wc -l > 127 > aldebaran:~/git> git log --pretty=oneline -i --grep llvm | wc -l > 1 I left out: aldebaran:~/git> git log --pretty=oneline -i --grep clang | wc -l 5 Still well within the 90%+ figure. Thanks, Ingo