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=-5.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 DCEF4C433DF for ; Sat, 20 Jun 2020 07:44:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B9FF923A1E for ; Sat, 20 Jun 2020 07:44:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="I3udPM4L" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726545AbgFTHo0 (ORCPT ); Sat, 20 Jun 2020 03:44:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40588 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725835AbgFTHoZ (ORCPT ); Sat, 20 Jun 2020 03:44:25 -0400 Received: from mail-io1-xd41.google.com (mail-io1-xd41.google.com [IPv6:2607:f8b0:4864:20::d41]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 41C01C06174E; Sat, 20 Jun 2020 00:44:25 -0700 (PDT) Received: by mail-io1-xd41.google.com with SMTP id o5so13877745iow.8; Sat, 20 Jun 2020 00:44:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:reply-to:from:date:message-id :subject:to:cc; bh=R3DIeUaXv04N92HP3WFMAv9JRTr9DLfjsPtXt3CI6Tc=; b=I3udPM4LUAU735jznatS8AR+IH1rD5XL+ktc1ev9knbyqIMQJhEzVB6x0+U0GN1M+P Sg6NvO1I/0YxOmZI0K71uARUW7eicLqpyZw83s8x4Dg+1wyz/0tt7gmkY3LKY1xXA6U+ qvnr+ZJyeJ1P/BnrHiV+G5QeGSqqcFkaLXeLGunIBUKnYLo1YhK9icEifr/zEJVCi0r1 DJJwYIF0K7WrZx0TfnpbYqqAJS1k9Ph3Y0qyX/10Pe+n87gndkzGY/qVURatAeMTxtPL z/1kuOFWZnIpVSFgKHpUfX8K8zJjFAtq6jTu9P9bonNQBvYiSassIA165oRfGI9RNbgU Zthw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:reply-to :from:date:message-id:subject:to:cc; bh=R3DIeUaXv04N92HP3WFMAv9JRTr9DLfjsPtXt3CI6Tc=; b=eiLtur44kS9S1IKvN25MVxmQfT6ntLBworXgp5Pfc2EY9n44ZYopnCK1V4MRU+vmzU WztRG+OEjsZxt2BnRgQ9UZ5E47ryXDeaFg30uM2WHVCFS/+hKVa18GkQv3K3MMqu2z37 w2s+CCP+0WPduo0WeRop+/Sz3a4kjRV49yMLcusQpiq6eo/cyCxNy/m9RDz1ZN3fUyFf uTu9cjEQ6QDDHnv5V8sD8Ocfp9FCeEJM05mDGhEw8Tp3xBH+MzaaTmLAPMaau23jmO/c U7lMl4ir4OoE+EeZQeniJjRTIllr2lSLeVjrsTkTigT9cgYFP7I0nniTUQp8jhpu0es6 d66g== X-Gm-Message-State: AOAM531xsRRuD5QU4tEr1lfQd+dnc2rdi/doRTRi3G6H5N4mp1kJX2CD iSF3AZdoeBmOzNhbtuZJNyqwV1P2ACN6ug50kro= X-Google-Smtp-Source: ABdhPJxT6aTrvzVXVZfaZQXlxk5xLyxN6TlYGQxy8b2/fW7uWBZtuTtwPl4kSlc6YmqQt4b54+St+in2RtL5E3TUfM4= X-Received: by 2002:a05:6602:2dca:: with SMTP id l10mr8269728iow.163.1592639064282; Sat, 20 Jun 2020 00:44:24 -0700 (PDT) MIME-Version: 1.0 References: <20200619010513.GW8681@bombadil.infradead.org> In-Reply-To: Reply-To: sedat.dilek@gmail.com From: Sedat Dilek Date: Sat, 20 Jun 2020 09:44:12 +0200 Message-ID: Subject: Re: Parallel compilation performance regression To: "Derrick, Jonathan" Cc: "willy@infradead.org" , "linux-fsdevel@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "dhowells@redhat.com" Content-Type: text/plain; charset="UTF-8" Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Sat, Jun 20, 2020 at 5:53 AM Derrick, Jonathan wrote: > > On Thu, 2020-06-18 at 18:05 -0700, Matthew Wilcox wrote: > > On Thu, Jun 18, 2020 at 11:52:55PM +0000, Derrick, Jonathan wrote: > > > Hi David, > > > > > > I've been experiencing a performance regression when running a parallel > > > compilation (eg, make -j72) on recent kernels. > > > > I bet you're using a version of make which predates 4.3: > > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0ddad21d3e99c743a3aa473121dc5561679e26bb > > > > I am! > > # make --version > GNU Make 4.2.1 > > > Thank you Matthew! Check your distribution and included patches on top of a vanilla make v4.2. Debian had some important ones I described in [1]. When proposing "make version 4.3" for tc-build - an opportunity to build a llvm-toolchain the easy way - we saw different numbers. I pointed in [1] to the Linus patch Matthew did here. Personally, with switching to Debian's make version 4.3-3 I have seen no big differences when using "make -j3" to build Linux v5.7+. That might be different with "make -j72"... ...can I have SSH access to this machine, please :-), You forgot to tell which Linux version you use. If you are interested please look at closed tc-build issue #72 for our analysis. For tc-build it did not matter - (Debian's) make v4.2 had some slightly better performance. BTW, with that pipe improvements in Linux v5.7 I see some better numbers when using pipebench to benchmark my devices: Example: SanDisk iSSD 16GB root# cat /dev/sdb | pipebench > /dev/null Summary: Piped 14.91 GB in 00h01m25.20s: 179.23 MB/second Before: approx. 100MB/s BTW, I heard of hyperfine benchmark tool the first time when dealing with make performance (see [2]) in ClangBuiltLinux. I would like to see some benchmark numbers with hyperfine from you if you do not mind. Stay OPEN minded and curious. Thanks. - Sedat - [1] https://github.com/ClangBuiltLinux/tc-build/issues/72 [2] https://github.com/sharkdp/hyperfine [3] https://github.com/sharkdp/hyperfine/releases