Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753381AbbFRHdj (ORCPT ); Thu, 18 Jun 2015 03:33:39 -0400 Received: from us01smtprelay-2.synopsys.com ([198.182.60.111]:39389 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751867AbbFRHdd (ORCPT ); Thu, 18 Jun 2015 03:33:33 -0400 Message-ID: <5582742D.9090206@synopsys.com> Date: Thu, 18 Jun 2015 13:03:01 +0530 From: Vineet Gupta User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 Newsgroups: gmane.linux.kernel.cross-arch,gmane.linux.kernel To: Geert Uytterhoeven CC: Michal Marek , "linux-arch@vger.kernel.org" , lkml Subject: Re: subtle side effect of commit a1c48bb160f836 References: <55826966.6050202@synopsys.com> In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.12.197.3] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1516 Lines: 36 On Thursday 18 June 2015 12:40 PM, Geert Uytterhoeven wrote: > On Thu, Jun 18, 2015 at 8:47 AM, Vineet Gupta > wrote: >> > commit a1c48bb160f8368 "Makefile: Fix unrecognized cross-compiler command line >> > options" moved ARCH specific cc option handling before common -Os/O2 setup. >> > >> > For ARC this had a subtle effect that we can no longer over-ride generic -O2 with >> > -O3, hence a performance regression observed going from 3.13 to 3.18 (the above >> > commit went into 3.16) >> > >> > I want to understand how to properly fix this. Moving the include of arch makefile >> > will bring back the old issue. I can introduce another option to set default optim >> > level, but only arc/m32r care about it anyways. > Can we include $(srctree)/arch/$(SRCARCH)/Makefile twice? Something like this would be ideal, but does that not bring back your warnings ? > > Or perhaps we can not apply the extra -O* if there's already a -O* option? Could be, but I'm not sure how to do that ? > Alternatively, as we already have CONFIG_CC_OPTIMIZE_FOR_SIZE, > a(nother) Kconfig option may make sense. I can cook this one - but is it really worth doing when only 2 arches care. Michal, do you have any opinion on how to solve this ? -Vineet -- 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/