From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0EC48C46470 for ; Tue, 7 Aug 2018 11:59:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C47A32178F for ; Tue, 7 Aug 2018 11:59:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C47A32178F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388890AbeHGONn (ORCPT ); Tue, 7 Aug 2018 10:13:43 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:54378 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727572AbeHGONm (ORCPT ); Tue, 7 Aug 2018 10:13:42 -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 w77Bx3Eh146591 for ; Tue, 7 Aug 2018 07:59:41 -0400 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0b-001b2d01.pphosted.com with ESMTP id 2kq9604cgt-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 07 Aug 2018 07:59:41 -0400 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 7 Aug 2018 12:59:37 +0100 Received: from b06cxnps3075.portsmouth.uk.ibm.com (9.149.109.195) by e06smtp05.uk.ibm.com (192.168.101.135) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 7 Aug 2018 12:59:34 +0100 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w77BxXnS20381940 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 7 Aug 2018 11:59:33 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BD62F11C054; Tue, 7 Aug 2018 14:59:40 +0100 (BST) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 620A411C04C; Tue, 7 Aug 2018 14:59:40 +0100 (BST) Received: from localhost (unknown [9.152.212.155]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Tue, 7 Aug 2018 14:59:40 +0100 (BST) Date: Tue, 7 Aug 2018 13:59:31 +0200 From: Vasily Gorbik To: Andi Kleen Cc: Masahiro Yamada , Michal Marek , Martin Schwidefsky , Heiko Carstens , Steven Rostedt , Ingo Molnar , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Subject: Re: [PATCH 2/4] trace: avoid calling cc-option -mrecord-mcount for every Makefile References: <20180806180740.GI4238@tassilo.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20180806180740.GI4238@tassilo.jf.intel.com> X-TM-AS-GCONF: 00 x-cbid: 18080711-0020-0000-0000-000002B35FBA X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18080711-0021-0000-0000-000021006605 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-08-07_04:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=983 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1808070123 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 06, 2018 at 11:07:40AM -0700, Andi Kleen wrote: > On Mon, Aug 06, 2018 at 03:17:44PM +0200, Vasily Gorbik wrote: > > Currently if CONFIG_FTRACE_MCOUNT_RECORD is enabled -mrecord-mcount > > compiler flag support is tested for every Makefile. > > Good catch. Does it make a measurable compile time difference? > A bit more than couple of seconds, but it does make a difference for a delta build: with patch: real 0m9.405s user 0m6.966s sys 0m2.287s without: real 0m12.153s user 0m9.058s sys 0m3.026s with -j48 on s390 24 cores lpar: with patch: real 0m1.949s user 0m7.034s sys 0m2.400s without: real 0m2.255s user 0m9.243s sys 0m3.266s > > > > Top 4 cc-option usages: > > 511 -mrecord-mcount