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=DKIM_SIGNED,DKIM_VALID, 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 EB28AC432C3 for ; Sat, 16 Nov 2019 07:18:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8100C20723 for ; Sat, 16 Nov 2019 07:18:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nifty.com header.i=@nifty.com header.b="yE7QrN1y" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726748AbfKPHSm (ORCPT ); Sat, 16 Nov 2019 02:18:42 -0500 Received: from conssluserg-06.nifty.com ([210.131.2.91]:55423 "EHLO conssluserg-06.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726197AbfKPHSm (ORCPT ); Sat, 16 Nov 2019 02:18:42 -0500 Received: from mail-ua1-f53.google.com (mail-ua1-f53.google.com [209.85.222.53]) (authenticated) by conssluserg-06.nifty.com with ESMTP id xAG7IPvp009560 for ; Sat, 16 Nov 2019 16:18:26 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conssluserg-06.nifty.com xAG7IPvp009560 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1573888706; bh=wEcD40KlL4hRWN44PHTQtvlzIboJTCA/cT3il2X2CW0=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=yE7QrN1ydIRr0LnmwncAIJefKyfPe1sj4FG1Ox/O7u3o/7b8Uc6l3PrUg3pExNgeF gCH/tGDIR7pmdtrGTBaixBtsYCcyxOgTTtWfhJ4Abq22UvWYDseFNZ4vSJz8Z7nBPW +UGZZo0UycMNZlGzHZJb9LWvosuDBs2PPPQjID+wSWtGRywVyA4Q4i7b+UG0bMHAGc gsJ6MIlOG9JxePnl7mJiV4axPD4IbkGUmplg/h3vbqtTemSHd8Cs2i2p9LdjXG8lv+ d4ShEo8rRm3QukhCLtALwD9fZj9/6EhNr65EIggsJH+aUjcziPpOIOPyQpzK2KRSti SgIqLNp88KOtA== X-Nifty-SrcIP: [209.85.222.53] Received: by mail-ua1-f53.google.com with SMTP id o9so3718545uat.8 for ; Fri, 15 Nov 2019 23:18:26 -0800 (PST) X-Gm-Message-State: APjAAAV0Vc3f3T23RQgm2MFseVQ4wrygnZDjLG80zo7PIn+cLUXxoUJP ydk8dup9yWPQCX4WRRTO+0GLbC6D8lVXXxKU5DI= X-Google-Smtp-Source: APXvYqw3sHv8rd4DoJC83katM0DWjVv8RJpz4kKYhH4b6sa+dC+Og/B5BDNeVedVpIDNg3XF5LW+hwbBWKQfVo1KYUM= X-Received: by 2002:a9f:3015:: with SMTP id h21mr11902836uab.95.1573888704938; Fri, 15 Nov 2019 23:18:24 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Masahiro Yamada Date: Sat, 16 Nov 2019 16:17:49 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: Recent slowdown in single object builds To: Jens Axboe Cc: "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Nov 16, 2019 at 8:10 AM Jens Axboe wrote: > > 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... This is necessary cost to do single builds (394053f4a4b3e3eeeaa67b67fc886a9a75bd9e4d) but, it is much better in linux-next. -- Best Regards Masahiro Yamada