Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932147AbZDWWNS (ORCPT ); Thu, 23 Apr 2009 18:13:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757042AbZDWWNA (ORCPT ); Thu, 23 Apr 2009 18:13:00 -0400 Received: from terminus.zytor.com ([198.137.202.10]:33037 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753390AbZDWWNA (ORCPT ); Thu, 23 Apr 2009 18:13:00 -0400 Message-ID: <49F0E6FD.8030108@zytor.com> Date: Thu, 23 Apr 2009 15:09:01 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.21 (X11/20090320) MIME-Version: 1.0 To: Joe Damato CC: Andi Kleen , Ingo Molnar , Jeff Garzik , Linus Torvalds , LKML , Thomas Gleixner , Ingo Molnar , x86@kernel.org Subject: Re: [PATCH] X86-32: Let gcc decide whether to inline memcpy was Re: New x86 warning References: <49EEBD3C.3060009@garzik.org> <20090422070157.GA28438@elte.hu> <8763gxoz50.fsf_-_@basil.nowhere.org> <3605561d0904221649n169dc579xb0694297154d97fa@mail.gmail.com> <49EFC8FE.7010403@zytor.com> <3605561d0904231422s57bd4cedl722be1dabf27428f@mail.gmail.com> In-Reply-To: <3605561d0904231422s57bd4cedl722be1dabf27428f@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 972 Lines: 28 Joe Damato wrote: > > Looks like this thread is dead/dying, but figured I should reply with > my test findings. The number of out-of-line calls (as determined by: > make mrproper && make defconfig && make && objdump -d vmlinux | grep > "call.*\ > gcc 4.2.4 - withOUT memset patch: 20 > gcc 4.2.4 - with memset patch: 365 > > gcc 3.4 - withOUT memset patch: 17 > gcc 3.4 - with memset patch: 349 > > I'm guessing this is probably not acceptable, so I won't bother > installing/trying gcc-3.2 unless anyone thinks that a 300+ increase in > out-of-line calls is OK. > Not unless it can be proven those calls are in non-performance-critical contexts. That's a lot of work to go through, though. -hpa -- 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/