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=-4.1 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 4FC5020248 for ; Tue, 5 Mar 2019 12:57:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727590AbfCEM5q (ORCPT ); Tue, 5 Mar 2019 07:57:46 -0500 Received: from mail-it1-f169.google.com ([209.85.166.169]:55379 "EHLO mail-it1-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726301AbfCEM5p (ORCPT ); Tue, 5 Mar 2019 07:57:45 -0500 Received: by mail-it1-f169.google.com with SMTP id z131so3910050itf.5 for ; Tue, 05 Mar 2019 04:57:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=2bFEYfeJGX1DVKMx1u7tJT8s42+/eUmywnUz5Kv00tE=; b=amtfh3MWT4p2ofO8+ZuUgaNkxxvz8T4LvWyTawe1agOPJK3GTLt2ThW2jhZhOrxfxX 8G7efTGIudDABHpKf8A1GV7EDgmwJKSDER+oJSBTHheNHxHJqgfejpqEUEFmZkQjiLZR KZgT+HuxwSD6TWgx+Txctn9KF1qHOmRe+bwGXK+l0JfD8IkZbXMxVdoU8Gj1iYATb0NK 5d51nQB0MtHTo9NpbYMR1dZ6SWuTcATisqvwYRVXDKXwXIizUqC4fMG7LqadaHpeZMOL 4T792woY2QTxzshUK5WQP2xXQRjXD8lvuw5ANNUcrzdrC+TwmiTiQGtOMX4YpNvBTgFL HKlA== 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=2bFEYfeJGX1DVKMx1u7tJT8s42+/eUmywnUz5Kv00tE=; b=tQ7lhu03XKGGGOy5zl4Lo5aXKjR02Hb/sJYIVGLWgw09KgszgvRSjf5GTQcGQ6LcCN nRz5Btj4XILgWusKny2O/T6pljJ4mD7ePGrtyhAXJEhLNhqC/w9/6WJXiasq1SA4VUa6 rlMAx24JJm4OFEzphm4FuPNBTEEFlDmB6fZPZNThHDztXwJIj6bQimGjkI/sGP5g84JS FYccf+ALw+YzDXmx+3GTlyiyoSTeyDMHFx50rF/F8JK+vY0MW9bn17G6Ja/Popq4P7gz nNoMSFbZT2Gm4HVPC6f2S+aX+sEMscBgIfvBeNRqn5YMymp4odAgyg/EgYrTD0uc75uo or7Q== X-Gm-Message-State: APjAAAVBsJFUg2vjSYQ0lCEzfEq+Pz8RFuWSH3t6C7ZzA+eLuJWBAj9t m3s65Zwj/8vLbMNunRWmTYB5bxX1GMmlS2WOy6U= X-Google-Smtp-Source: APXvYqx2KslmGxUu5RqcKL7xNVlXvtdWPwcgTmCYwlzCYAWfpN2YE6cleCoZ9BGgrsnJs1W3g3o8Zn26ISN/aOv2BCc= X-Received: by 2002:a24:3b0a:: with SMTP id c10mr2167504ita.10.1551790665143; Tue, 05 Mar 2019 04:57:45 -0800 (PST) MIME-Version: 1.0 References: <20190302150900.GU6085@hank.intra.tgummerer.com> <20190305045140.GH19800@sigill.intra.peff.net> In-Reply-To: <20190305045140.GH19800@sigill.intra.peff.net> From: Duy Nguyen Date: Tue, 5 Mar 2019 19:57:18 +0700 Message-ID: Subject: Re: Questions on GSoC 2019 Ideas To: Jeff King Cc: Christian Couder , Thomas Gummerer , Matheus Tavares Bernardino , git , =?UTF-8?B?0J7Qu9GPINCi0LXQu9C10LbQvdCw0Y8=?= , Elijah Newren , Tanushree Tumane 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 Tue, Mar 5, 2019 at 11:51 AM Jeff King wrote: > > processing power from multiple cores, but about _not_ blocking. I > > think one example use case here is parallel checkout. While one thread > > is blocked by pack access code for whatever reason, the others can > > still continue doing other stuff (e.g. write the checked out file to > > disk) or even access the pack again to check more things out. > > I'm not sure if it would help much for packs, because they're organized > to have pretty good cold-cache read-ahead behavior. But who knows until > we measure it. > > I do suspect that inflating (and delta reconstruction) done in parallel > could be a win for git-grep, especially if you have a really simple > regex that is quick to search. Maybe git-blame too. But this is based purely on me watching CPU utilization of one command with hot cache. For git-blame though, diff code as to be thread safe too but that's another story. -- Duy