From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:36686 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727529AbeHGHnC (ORCPT ); Tue, 7 Aug 2018 03:43:02 -0400 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w775SrsO133455 for ; Tue, 7 Aug 2018 01:30:25 -0400 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0b-001b2d01.pphosted.com with ESMTP id 2kq54ege4n-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 07 Aug 2018 01:30:25 -0400 Received: from localhost by e06smtp01.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 7 Aug 2018 06:30:24 +0100 Date: Tue, 7 Aug 2018 07:30:17 +0200 From: Heiko Carstens Subject: Re: [PATCH 4/4] s390/ftrace: add -mfentry and -mnop-mcount support References: MIME-Version: 1.0 In-Reply-To: Message-Id: <20180807053017.GA6613@osiris> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit Content-Disposition: inline Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Vasily Gorbik Cc: Masahiro Yamada , Michal Marek , Martin Schwidefsky , Steven Rostedt , Ingo Molnar , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, Andi Kleen On Mon, Aug 06, 2018 at 03:17:47PM +0200, Vasily Gorbik wrote: > Utilize -mfentry and -mnop-mcount gcc options together with > -mrecord-mcount to get compiler generated calls to the profiling functions > as nops which are compatible with current -mhotpatch=0,3 approach. At the > same time -mrecord-mcount enables __mcount_loc section generation by > the compiler which allows to avoid using scripts/recordmcount.pl script. > > Signed-off-by: Vasily Gorbik > --- > arch/s390/Kconfig | 2 ++ > arch/s390/Makefile | 16 +++++++++------- > arch/s390/include/asm/ftrace.h | 6 +++--- > arch/s390/kernel/ftrace.c | 2 +- > arch/s390/kernel/mcount.S | 2 +- > 5 files changed, 16 insertions(+), 12 deletions(-) Do you have numbers which tell how much this reduces the compile time of the kernel on s390? I assume this change makes quite some difference. Reviewed-by: Heiko Carstens