From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755749AbdEEGno convert rfc822-to-8bit (ORCPT ); Fri, 5 May 2017 02:43:44 -0400 Received: from terminus.zytor.com ([65.50.211.136]:53051 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752624AbdEEGnn (ORCPT ); Fri, 5 May 2017 02:43:43 -0400 Date: Thu, 04 May 2017 23:38:57 -0700 User-Agent: K-9 Mail for Android In-Reply-To: <20170505062333.hvaxghrpy5mgpksf@gmail.com> References: <20170504191409.ptpxg4ooxfqipy3z@treble> <20170505031730.6741-1-nick.desaulniers@gmail.com> <20170505062333.hvaxghrpy5mgpksf@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Subject: Re: [Patch v2] x86/build: require only gcc use -maccumulate-outgoing-args To: Ingo Molnar , Nick Desaulniers CC: jpoimboe@redhat.com, tglx@linutronix.de, mingo@redhat.com, x86@kernel.org, linux-kernel@vger.kernel.org From: hpa@zytor.com Message-ID: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On May 4, 2017 11:23:33 PM PDT, Ingo Molnar wrote: > >* Nick Desaulniers wrote: > >> Other compilers, like clang, treat unknown compiler flags as errors. >> >> Signed-off-by: Nick Desaulniers >> --- >> arch/x86/Makefile | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/arch/x86/Makefile b/arch/x86/Makefile >> index 4430dd489620..12757a252e6b 100644 >> --- a/arch/x86/Makefile >> +++ b/arch/x86/Makefile >> @@ -179,7 +179,7 @@ ifdef CONFIG_JUMP_LABEL >> endif >> >> ifeq ($(ACCUMULATE_OUTGOING_ARGS), 1) >> - KBUILD_CFLAGS += -maccumulate-outgoing-args >> + KBUILD_CFLAGS += $(if $(filter >gcc,$(cc-name)),-maccumulate-outgoing-args) >> endif >> >> # Stackpointer is addressed different for 32 bit and 64 bit x86 > >The justification Josh gave for this pattern should be put into a >comment and into >the changelog as well. > >Thanks, > > Ingo However, I don't think Josh's explanation is correct. I am pretty sure it is a performance issue, not a correctness issue, and besides, a version of gcc that old won't be able to compile the kernel for other reasons, as evidenced by the fact that noone has complained about this option being mandatory. -- Sent from my Android device with K-9 Mail. Please excuse my brevity.