From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: Re: [PATCH 5/7] kvm tools: enable LTO Date: Thu, 30 Aug 2012 10:33:21 +0200 Message-ID: <503F2551.2080909@gmail.com> References: <1346312203-29456-1-git-send-email-levinsasha928@gmail.com> <1346312203-29456-5-git-send-email-levinsasha928@gmail.com> <20120830081654.GA3741@gmail.com> <20120830082217.GG21422@moon> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Pekka Enberg , Ingo Molnar , asias.hejun@gmail.com, mingo@elte.hu, kvm@vger.kernel.org To: Cyrill Gorcunov Return-path: Received: from mail-ee0-f46.google.com ([74.125.83.46]:59627 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751358Ab2H3IdP (ORCPT ); Thu, 30 Aug 2012 04:33:15 -0400 Received: by eekc1 with SMTP id c1so582154eek.19 for ; Thu, 30 Aug 2012 01:33:14 -0700 (PDT) In-Reply-To: <20120830082217.GG21422@moon> Sender: kvm-owner@vger.kernel.org List-ID: On 08/30/2012 10:22 AM, Cyrill Gorcunov wrote: > On Thu, Aug 30, 2012 at 10:16:54AM +0200, Ingo Molnar wrote: >> >> * Pekka Enberg wrote: >> >>> On Thu, Aug 30, 2012 at 10:36 AM, Sasha Levin wrote: >>>> Build with -flto set, which should enable link-time-optimizations. >>>> >>>> I'm not sure if it provides a significant performance increase, but >>>> it's probably just worth it for catching issues which it may cause. >>>> >>>> Signed-off-by: Sasha Levin >>> >>> Ingo, any objections to this? >> >> No objections if you can live with a 2x-4x increase in build >> time - at worst it might cause funnies with the BIOS linker >> script and such. > > Maybe we could enable it via some make option? > Say make LTO=1 or something? Build time went from 6 sec to 14, I don't think it's that significant...