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=-16.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 B3F8EC433C1 for ; Mon, 29 Mar 2021 22:53:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 87FB16198E for ; Mon, 29 Mar 2021 22:53:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231135AbhC2WxG (ORCPT ); Mon, 29 Mar 2021 18:53:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41128 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230161AbhC2Wwi (ORCPT ); Mon, 29 Mar 2021 18:52:38 -0400 Received: from mail-qv1-xf4a.google.com (mail-qv1-xf4a.google.com [IPv6:2607:f8b0:4864:20::f4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 659B9C061762 for ; Mon, 29 Mar 2021 15:52:38 -0700 (PDT) Received: by mail-qv1-xf4a.google.com with SMTP id da16so11943087qvb.2 for ; Mon, 29 Mar 2021 15:52:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=q+pONZ+c5gzLHZlc8vklxdpHbUYpIrWC8EjxE4Qzlnc=; b=i2KpWGdI/+ml8LNXX0aSU7N82qqTntdTDZjcHo8J2MMruG576SgALMQkjAX6KOXceW IrOVZ+cozFtEm6yTSStYwgQWftf2uFZcl/rgv2EGbcV3zTZxg/iLBHymUt/sQAx1kMYu viD7uqt2Mp4iqZsQWvx6T6WiIZHhpe6YkpdeUIPXwRZWKTcZU36ciArP6/nQp96X0QRX lhSB7s6xq/ddvkbqhYHYvvAE3bkN9L5MQ6BUhWL7Q9Ys0eUDQObZlFK1jHsbRlJRcgcv 7F9SysQBjk9MQ9/LDhz/vAMJTZItQ/ppdSVI14TrjXvtGM9v8QyzL/Kz6Evt5CWBdB20 cVyw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=q+pONZ+c5gzLHZlc8vklxdpHbUYpIrWC8EjxE4Qzlnc=; b=m9gFqZMG+QeBeXG0657zBHRnRmmI4i27/aR8xIn3t1SN7FWJ8Nr6hiNA6R5yIbDqAk 0NQuoj0eiHixDB14hCdTvudacD64cSkFW8Dn2xwvF6bHdcyEoyv/YfDiV/WjrcmxpBfZ vpqL/aPsvVUksUgMhEU1EjKbOkoNjQP0QRp8NPSndrwkNvBu5cgvfwpiL5blsOXz6jsq 1DEbTL3VU7/8H7i6uMHy8LQaE+16165PJ8PVp9LQaDzH32YCusYkOWJVpoxlGeWp1+e4 JwNq9ZjO/dbR+GNGhkOowhwGpBhg0pRlEId3BbQZGBW3Ql3kjka6bBXPRmYhDuDJTsBI g/oQ== X-Gm-Message-State: AOAM530E643gXJ1zgVI46FYpoNH0+Rld/akPZATo1h3K5gP2j5sFblZL kweprDtjEHc4OVbdFwFM7Hzi8pZDk9H9NgcsVyM= X-Google-Smtp-Source: ABdhPJz7NMMYH+EO7jPPhn+82vEbQx/l4SdUF0/BAZVldxnLPfgrSAWzVrLnKVkVhoFUEptinOdh+noYxp2C71l/FFY= X-Received: from ndesaulniers1.mtv.corp.google.com ([2620:15c:211:202:c959:2751:3fb4:47b1]) (user=ndesaulniers job=sendgmr) by 2002:ad4:4431:: with SMTP id e17mr27689931qvt.37.1617058357412; Mon, 29 Mar 2021 15:52:37 -0700 (PDT) Date: Mon, 29 Mar 2021 15:52:35 -0700 In-Reply-To: <20210328064121.2062927-1-yhs@fb.com> Message-Id: <20210329225235.1845295-1-ndesaulniers@google.com> Mime-Version: 1.0 References: <20210328064121.2062927-1-yhs@fb.com> X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: Re: [PATCH kbuild] kbuild: add -grecord-gcc-switches to clang build From: Nick Desaulniers To: yhs@fb.com Cc: arnaldo.melo@gmail.com, ast@kernel.org, bpf@vger.kernel.org, kernel-team@fb.com, linux-kbuild@vger.kernel.org, masahiroy@kernel.org, michal.lkml@markovi.net, clang-built-linux@googlegroups.com, sedat.dilek@gmail.com, morbo@google.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org (replying to https://lore.kernel.org/bpf/20210328064121.2062927-1-yhs@fb.com/) Thanks for the patch! > +# gcc emits compilation flags in dwarf DW_AT_producer by default > +# while clang needs explicit flag. Add this flag explicitly. > +ifdef CONFIG_CC_IS_CLANG > +DEBUG_CFLAGS += -grecord-gcc-switches > +endif > + This adds ~5MB/1% to vmlinux of an x86_64 defconfig built with clang. Do we want to add additional guards for CONFIG_DEBUG_INFO_BTF, so that we don't have to pay that cost if that config is not set?