From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.9 required=3.0 tests=AWL,BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id DFDE820A1E for ; Fri, 14 Dec 2018 19:11:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730460AbeLNTK7 (ORCPT ); Fri, 14 Dec 2018 14:10:59 -0500 Received: from mail-io1-f54.google.com ([209.85.166.54]:38127 "EHLO mail-io1-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730410AbeLNTK7 (ORCPT ); Fri, 14 Dec 2018 14:10:59 -0500 Received: by mail-io1-f54.google.com with SMTP id l14so5278737ioj.5 for ; Fri, 14 Dec 2018 11:10:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=atlassian-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=khv48W5VEMGl8Zv3GZfG0srs6E7+3EVJQyA/3ODNz+c=; b=MAqISEalqFwsRI8n7zc+DCbWHAn2FkKUpvrQqDDQNhPWtU9sXPo2OCUA+/WAzNnGk0 v/7pOHMQnSEUtqY5/QlT4PMmfw2vY6WhZ3udHGCPro9iDcF6SctlPPEF77HtXuaoV9tM WDtrMjMpYsvP7Ak3WDN7GFsMH+FDTc8EAZw5l0qOEAvh/0HMtdqkUzwax3CbeQ6uZllq dL4UIKC3+6YD3a374nxZGgDAJSBhsDk6oFcnreYFRe+u6CIOjBAephZ5Y8N5BAvXgc3e L5XqecL9AqUpEPtXTz+W7zWvDYNhn+DS4hLjp2SdRwmvRfs3qvHRvelYbXqZFcL9PaEJ wFsA== 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:from:date :message-id:subject:to:cc; bh=khv48W5VEMGl8Zv3GZfG0srs6E7+3EVJQyA/3ODNz+c=; b=hbCirUK61pVEV7cGkeoaLYUVuRxK0ZIcEfr4oBnpsBiFDCRItf74DYAQkMShR4PJFq 0UPVYPP5w+S+qcibr9cQsCsRVhfjw/EybcMFSyyc6BRXd2RKHTczCRXjfX5s4U9ejhuR fyJ8TdY8f3aTP+vlkROijIcmpkHs4hPneXF8CORerA1Rc53b5iBonAlgv4YVk4t1VWlv /gVXMxIyrIDjuK0A2kC0DPLbaCFgn3kopUAzskn8Z1uprA9oYk2XNo7q8u/K/aRQYc8C KwpMFuUccsYsjN4rzPKDPL8I/kfiihYwwlpqbZgoIWjFvDiBXdeofYyOG2uikmFo2UUM fbcw== X-Gm-Message-State: AA+aEWZbFzE9xnLpntqt5mtebiWhvtBFHmnhbP3FBxnVaLBwYBzIBQlk FQB7Xv5FIM9ExjXqRYPnls/QmlR8bOUpownGbp+87EZzWpw= X-Google-Smtp-Source: AFSGD/U4TJhRMElrKEFfAESV6OP0rqWuhiUIY2ptiZI1nil9cNPt7m82XI2FpfQc2AZr/Og2H5HpECHDjXeQh0/HN9Y= X-Received: by 2002:a6b:f80e:: with SMTP id o14mr3733471ioh.68.1544814658107; Fri, 14 Dec 2018 11:10:58 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Bryan Turner Date: Fri, 14 Dec 2018 11:10:47 -0800 Message-ID: Subject: Re: Git blame performance on files with a lot of history To: clement.moyroud@gmail.com Cc: Git Users Content-Type: text/plain; charset="UTF-8" Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Fri, Dec 14, 2018 at 10:29 AM Clement Moyroud wrote: > > Hello, > > My group at work is migrating a CVS repo to Git. The biggest issue we > face so far is the performance of git blame, especially compared to > CVS on the same file. One file especially causes us trouble: it's a > 30k lines file with 25 years of history in 3k+ commits. The complete > repo has 200k+ commits over that same period of time. After you converted the repository from CVS to Git, did you run a manual repack? The process of converting a repository from another SCM often results in poor delta chain selections which result in a repository that's unnecessarily large on disk, and/or performs quite slowly. Something like `git repack -Adf --depth=50 --window=200` discards the existing delta chains and chooses new ones, and may result in significantly improved performance. A smaller depth, like --depth=20, might result in even more performance improvement, but may also make the repository larger on disk; you'll need to find the balance that works for you. Might be something worth testing, if you haven't? Bryan