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=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 71E55C432C3 for ; Fri, 15 Nov 2019 23:10:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3887020730 for ; Fri, 15 Nov 2019 23:10:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="pT5JWBdC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727168AbfKOXKs (ORCPT ); Fri, 15 Nov 2019 18:10:48 -0500 Received: from mail-pg1-f172.google.com ([209.85.215.172]:39484 "EHLO mail-pg1-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727022AbfKOXKr (ORCPT ); Fri, 15 Nov 2019 18:10:47 -0500 Received: by mail-pg1-f172.google.com with SMTP id 29so6656240pgm.6 for ; Fri, 15 Nov 2019 15:10:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=to:cc:from:subject:message-id:date:user-agent:mime-version :content-language:content-transfer-encoding; bh=tQ3lvrS3blm9KMnMM0Lci3Z1sGKOamHxljOn3CuMDbY=; b=pT5JWBdCAjIGTWuNcLh+8kHAirWygCIcGtV+7SqbZj/KpGYc99JYbfhUZCrPPratnM d7NlCrAWgnZkYYPP/J9uSONJcYTmnCOGFerQFynY2FPqUP/VNw3O0Fg4aSfLaxWV7jT3 mvNDuBPOIW1lnvAPSQCglBlVnkqnUtENac8bjo9rce6G4UdH4gZZNpP5lAjk2E5hZsD/ hvsKERBv4q+n1jMC8yVUXJrg4yFsCy1mDlAaEJMcwH4Ifq5LblyMrENIVjNsIZc2gY4T ZI8FZc3Np0xPw6PHsAo9s7DE/jdxwkWaVvS8WijRM+KjiDH61HXyDJQg/n6CXZJ3CWmi nmcQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:cc:from:subject:message-id:date:user-agent :mime-version:content-language:content-transfer-encoding; bh=tQ3lvrS3blm9KMnMM0Lci3Z1sGKOamHxljOn3CuMDbY=; b=XLiuboC6zgpGcCX7OWR/XTcRh/Wjmm5/0VkM46p8yoUf5Avr13tC9xeL26xJ4Wpavz ShSY0r3VarKgBjF8NtQYwv3ih1G66GaedrAB//TzvjhnUmjI50YMbOX1YqWPLcdkjb0R Evv8RzcUcGF+zk+QxNGN37PUSUh0Wi/AJViNr1hsRTRXg94cJ9zIeJNks1DprELiRVNf OkXgYRwPJB16pC5uuLnE7eSfLf6m9SVynU3qz/UzJnkZn/2TnIr9Z1KUZSQ9GwiguXgD k31Bi1wPzuRpVpIkKNxebOQ9na4uq16FLh81ffbuO4dB3eEkEQrfTtR76/o39axx87yG epwQ== X-Gm-Message-State: APjAAAUwN0owGylRVhF8AkK+JcTxDOrST3N446Ccz75yIEklZRZSuUnb XVEL9vz9XWSD9AqafNsRr6NWXiQr7aE= X-Google-Smtp-Source: APXvYqy+4lU01UeVkOSTSTAdSRd9AT8DW/Xp+4MWRX3F8hpid7A+dV0245Knc+YxZRpdcznwGa62/w== X-Received: by 2002:aa7:8210:: with SMTP id k16mr20243455pfi.84.1573859445210; Fri, 15 Nov 2019 15:10:45 -0800 (PST) Received: from ?IPv6:2620:10d:c081:1134::115d? ([2620:10d:c090:180::be7a]) by smtp.gmail.com with ESMTPSA id b26sm11209631pfo.158.2019.11.15.15.10.43 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 15 Nov 2019 15:10:44 -0800 (PST) To: Masahiro Yamada Cc: "linux-kernel@vger.kernel.org" From: Jens Axboe Subject: Recent slowdown in single object builds Message-ID: Date: Fri, 15 Nov 2019 16:10:42 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, I've noticed that current -git is a lot slower at doing single object builds than earlier kernels. Here's an example, building the exact same file on 5.2 and -git: $ time make fs/io_uring.o real 0m5.953s user 0m5.402s sys 0m0.649s vs 5.2 based (with all the backports, identical file): $ time make fs/io_uring.o real 0m3.218s user 0m2.968s sys 0m0.520s Any idea what's going on here? It's almost twice as slow, which is problematic... -- Jens Axboe