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=-0.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 4949FC433E0 for ; Wed, 27 May 2020 12:50:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2B15F2053B for ; Wed, 27 May 2020 12:50:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730162AbgE0Muk (ORCPT ); Wed, 27 May 2020 08:50:40 -0400 Received: from mout.kundenserver.de ([212.227.17.24]:40779 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730085AbgE0Muj (ORCPT ); Wed, 27 May 2020 08:50:39 -0400 Received: from mail-qt1-f182.google.com ([209.85.160.182]) by mrelayeu.kundenserver.de (mreue109 [212.227.15.145]) with ESMTPSA (Nemesis) id 1M4bA0-1jcHM340LG-001iuT for ; Wed, 27 May 2020 14:50:38 +0200 Received: by mail-qt1-f182.google.com with SMTP id y1so8302052qtv.12 for ; Wed, 27 May 2020 05:50:37 -0700 (PDT) X-Gm-Message-State: AOAM533XfK+m0PwVoC+cdZqeF0LQ4SigZG+CSvh/ATeRHQ8V5JcaWRn0 A1u+eE8mSQ3DySJyjaRiNTim4YdfnUtKGYxsIHA= X-Google-Smtp-Source: ABdhPJx20udF+dw7mm7gvALJ3Shi6o19LcsetLnO/1t3pasrdggEXONy0LdbDLSI8is7yzMeSPhw064eSdt94SBno7I= X-Received: by 2002:ac8:1844:: with SMTP id n4mr3896231qtk.142.1590583836877; Wed, 27 May 2020 05:50:36 -0700 (PDT) MIME-Version: 1.0 References: <20200527103236.148700-1-elver@google.com> In-Reply-To: From: Arnd Bergmann Date: Wed, 27 May 2020 14:50:20 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH -tip] compiler_types.h: Optimize __unqual_scalar_typeof compilation time To: Sedat Dilek Cc: Marco Elver , Will Deacon , Peter Zijlstra , Borislav Petkov , Thomas Gleixner , Ingo Molnar , clang-built-linux , "Paul E. McKenney" , Dmitry Vyukov , Alexander Potapenko , Andrey Konovalov , kasan-dev , "linux-kernel@vger.kernel.org" , Nick Desaulniers , Stephen Rothwell Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K1:kFETjL0+C0Lrv27og+SqcX6djBmuPQsR8i4Uc7qTUGqX6Fu17v8 TsDgE4gP+Y+HJH+seBGW9tUZ7m/YYigAElbE8+QtHQS2wZr1d8kWOKfWtELRENSIwJW8+Xm VvbFEeIdIEwmooVUeGLsZDUa03NHI393HLXfsa1rdzD0QZ31BrbYNqC8QL4K5CqiKYI3Bc7 MQ5znmJ9EilxBkYAfVdsQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:yjc2mT/onzY=:2XXZzBi0EkKMa6VcNef6+k pwwHctM9w/RAvHjm/z6MXXXWZWMz6HE2A9U9t5AmqnVffTXypwrasnwFjK7ylScGfju0Gfi9P zWDKRrvAAWbcVFPfG+m5/xPG/gm/ar8AVI4H1z0wd0HzJZnerFicXbuHg/uqvY+nNnhHa1HBe eXVH4Bjm8NpyzImznrliC4keKsdXt8Y2ylnbe2dNQBKUle7I8SUau9qHY/AVkqcj6B6qsDYt3 J2QkfgFAbSTHKaBz9rJR6B6lXsSOV8wqMgkka5IomGgSFfWV4hq4598+nEhrV2ekUENQfDz4E wE0MZPEogKM/lu+mFjPWKkYx25VoL8S+/Qobj0mrgHWchkaxpH8XBxvtPYMltHOmwCC/+ReS1 ns1G2H424cNfaQUYndZ1TdsDv4xxSkHKYkqSN0utAT0nTli2JKaOrzXd6cUXV3nya01e0art0 9foTKexYAIjGfNoXElHmWRrlfnx9J4W7GFAR44XapW00iOdhwwZ3AUIp10YgAN1qSdyLNbJMe Hj05pE35FriQctvmm+SdI4/onKuk/23Kdn9Ah2mlgBxPGI1i2GT4oAmLnfGJcp8bHZV84IbwA txTuyQRduD3qYv9/eo4BtqUay0NRN2SDGFhj4VLLmli8TN0BM0GWCu8WzIuhMrvTWFJzMv1FV +rigUuOEVcYT9tyiGX+qxkt8fq7n6H0xBbodU2XHacuKyI54PQUV4eMBz6G/OmTGfFil+rNCE UyQFzf6jW9k660J40mF6oFTWKJz19BRWtGnfzpg2Abm8bKo6+D8/ofJJEjQ/4cs9Awob0/SQa 5nnEM9+SJZQtQ7BMRSW61sFb+4oNI6NI4QcQ1Y1Wh8F6bSudnE= Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 27, 2020 at 2:35 PM Sedat Dilek wrote: > On Wed, May 27, 2020 at 2:31 PM Arnd Bergmann wrote: > > On Wed, May 27, 2020 at 1:36 PM Sedat Dilek wrote: > > > On Wed, May 27, 2020 at 1:27 PM Arnd Bergmann wrote: > > > > On Wed, May 27, 2020 at 12:33 PM Marco Elver wrote: > > > > > > > > This gives us back 80% of the performance drop on clang, and 50% > > > > of the drop I saw with gcc, compared to current mainline. > > > > > > > > Tested-by: Arnd Bergmann > > > > > > > > > > Hi Arnd, > > > > > > with "mainline" you mean Linux-next aka Linux v5.8 - not v5.7? > > > > I meant v5.7. > > > > > I have not seen __unqual_scalar_typeof(x) in compiler_types.h in Linux v5.7. > > > > > > Is there a speedup benefit also for Linux v5.7? > > > Which patches do I need? > > > > v5.7-rc is the baseline and is the fastest I currently see. On certain files, > > I saw an intermittent 10x slowdown that was already fixed earlier, now > > linux-next > > is more like 2x slowdown for me and 1.2x with this patch on top, so we're > > almost back to the speed of linux-5.7. > > > > Which clang version did you use - and have you set KCSAN kconfigs - > AFAICS this needs clang-11? I'm currently using clang-11, but I see the same problem with older versions, and both with and without KCSAN enabled. I think the issue is mostly the deep nesting of macros that leads to code bloat. Arnd