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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 C8CDFC46471 for ; Mon, 6 Aug 2018 18:18:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7965620685 for ; Mon, 6 Aug 2018 18:18:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7965620685 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.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 S2387663AbeHFU2u (ORCPT ); Mon, 6 Aug 2018 16:28:50 -0400 Received: from mga17.intel.com ([192.55.52.151]:46278 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726279AbeHFU2t (ORCPT ); Mon, 6 Aug 2018 16:28:49 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Aug 2018 11:18:33 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,452,1526367600"; d="scan'208";a="78975165" Received: from tassilo.jf.intel.com (HELO tassilo.localdomain) ([10.7.201.126]) by fmsmga001.fm.intel.com with ESMTP; 06 Aug 2018 11:07:40 -0700 Received: by tassilo.localdomain (Postfix, from userid 1000) id 12A42301388; Mon, 6 Aug 2018 11:07:40 -0700 (PDT) Date: Mon, 6 Aug 2018 11:07:40 -0700 From: Andi Kleen To: Vasily Gorbik 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 Message-ID: <20180806180740.GI4238@tassilo.jf.intel.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) 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 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? > > Top 4 cc-option usages: > 511 -mrecord-mcount > 11 -fno-stack-protector > 9 -Wno-override-init > 2 -fsched-pressure > > To address that move cc-option from scripts/Makefile.build to top Makefile > and export CC_USING_RECORD_MCOUNT to be used in original place. > > While doing that also add -mrecord-mcount to CC_FLAGS_FTRACE (if gcc > actually supports it). > > Signed-off-by: Vasily Gorbik Acked-by: Andi Kleen -Andi