Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756826AbaDHWo2 (ORCPT ); Tue, 8 Apr 2014 18:44:28 -0400 Received: from mail-vc0-f174.google.com ([209.85.220.174]:47187 "EHLO mail-vc0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756210AbaDHWo0 (ORCPT ); Tue, 8 Apr 2014 18:44:26 -0400 MIME-Version: 1.0 In-Reply-To: <20140408204906.GA3616@cloud> References: <20140407201919.GA15838@sepie.suse.cz> <20140408204906.GA3616@cloud> Date: Tue, 8 Apr 2014 15:44:25 -0700 X-Google-Sender-Auth: ohU8ng_HM-3FjTJJ0rAOPMUB9ao Message-ID: Subject: Re: [GIT] kbuild/lto changes for 3.15-rc1 From: Linus Torvalds To: Josh Triplett Cc: Michal Marek , Andi Kleen , Linux Kbuild mailing list , Linux Kernel Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 8, 2014 at 1:49 PM, wrote: > > In addition to making the kernel smaller and such (I'll leave the > specific stats there to Andi), here's the key awesomeness of LTO that > you, personally, should find useful and compelling: LTO will eliminate > the need to add many lower-level Kconfig symbols to compile out bits of > the kernel. Actually that, to me, is a negative right now. Since there's no way we'll make LTO the default in the foreseeable future, people starting to use it like that is just a bad bad thing. So really, the main advantage of LTO would be any actual optimizations it can do. And call me anal, but I want *numbers* for that before I merge it. Not handwaving. I'm not actually aware of how well - if at all - code generation actually improves. Linus -- 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/