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=-9.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 15FF5C64E8A for ; Wed, 2 Dec 2020 12:55:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B7E5A2223F for ; Wed, 2 Dec 2020 12:55:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729981AbgLBMzB (ORCPT ); Wed, 2 Dec 2020 07:55:01 -0500 Received: from conssluserg-02.nifty.com ([210.131.2.81]:21995 "EHLO conssluserg-02.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727872AbgLBMy7 (ORCPT ); Wed, 2 Dec 2020 07:54:59 -0500 Received: from mail-pl1-f172.google.com (mail-pl1-f172.google.com [209.85.214.172]) (authenticated) by conssluserg-02.nifty.com with ESMTP id 0B2CrwPt017022; Wed, 2 Dec 2020 21:53:59 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conssluserg-02.nifty.com 0B2CrwPt017022 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1606913639; bh=vuORpWynQ+msTy9A4pkjY7EdykIPuUY4fBkBLNdds1I=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=1nx16JblC790bJmAZ1xYHXKZmc+9fDqZL78J7JuybTSn+d6qi1hgoiwyXKfY9Renl ZuBPRQ08/6zgwW86WJuHuFZBVsToZo/KmRMxJa+CrY8iVWSiKxUdlcTnrc/YWJ4/yV +aIdXBpEirv7o3ySgJPrHjz/H03t6FITkCRj6s532jnDdVTiEnbYFEgX+2p3mpYVVr DGDQcCeHklmU492sTaCON76ZbDFEx1c/sO2FEp/ctz02C6CBrw0QekQSEMR4sipqzL cmCvhhdrQYbWGzIh7vuz00Stzj82NvPeVHjjUzg+NgODvXCCQ6gfZh0Qo8fpJMNsni x+r1llflpQMCg== X-Nifty-SrcIP: [209.85.214.172] Received: by mail-pl1-f172.google.com with SMTP id r2so1081389pls.3; Wed, 02 Dec 2020 04:53:59 -0800 (PST) X-Gm-Message-State: AOAM530G2CaT5n3kCuc2CXzOLyUdANskbNCd5qqIEY1h3k4w/jOs0UUd T8I0jC+WqqvwfBr2jRkn/46Hi+YUVUZqn4DU0Y4= X-Google-Smtp-Source: ABdhPJzMK5zIztsquJ9LK5mqh5a3c9+MhxuXmUXbnBxX8NfGje2IPM6eNOgc2zbjgVpFz60/pBOVwLfSSL/v+BDGPUM= X-Received: by 2002:a17:90a:5905:: with SMTP id k5mr2288609pji.198.1606913638531; Wed, 02 Dec 2020 04:53:58 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Masahiro Yamada Date: Wed, 2 Dec 2020 21:53:20 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [GIT PULL 2/2] Kconfig updates for v5.10-rc1 To: Linus Torvalds Cc: Emese Revfy , Linux Kbuild mailing list , Linux Kernel Mailing List , Kees Cook Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Linus, On Sun, Nov 29, 2020 at 3:28 AM Linus Torvalds wrote: > > On Fri, Nov 27, 2020 at 11:05 PM Masahiro Yamada wrote: > > > > As for the cc1plus cost, I got a similar result. > > > > Running scripts/gcc-plugin.sh directly > > took me 0.5 sec, which is a fourth > > of the allmodconfig run-time. > > > > Actually, I did not know this shell script > > was so expensive to run... > > So it turns out that one reason it's so expensive to run is that it > does a *lot* more than it claims to do. > > It says "we need a c++ compiler that supports the designated > initializer GNU extension", but then it actually includes a header > file from hell, rather than just test designated initializers. > > This patch makes the cc1plus overhead go down a lot. That said, I'm > doubtful we really want gcc plugins at all, considering that the only > real users have all apparently migrated to clang builtin functionality > instead. > > Linus The attached patch looks OK to me. Just a nit: Now that the test code does not include any header, you can also delete "-I $srctree/gcc-plugins -I $gccplugins_dir/include" If you apply it directly, please feel free to add Reviewed-by: Masahiro Yamada -- Best Regards Masahiro Yamada