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: AS53758 23.128.96.0/24 X-Spam-Status: No, score=-3.8 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, SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by dcvr.yhbt.net (Postfix) with ESMTP id BEC7D1F670 for ; Mon, 25 Oct 2021 21:21:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232920AbhJYVYK (ORCPT ); Mon, 25 Oct 2021 17:24:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50612 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233020AbhJYVYJ (ORCPT ); Mon, 25 Oct 2021 17:24:09 -0400 Received: from mail-wm1-x336.google.com (mail-wm1-x336.google.com [IPv6:2a00:1450:4864:20::336]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8EB7BC061745 for ; Mon, 25 Oct 2021 14:21:46 -0700 (PDT) Received: by mail-wm1-x336.google.com with SMTP id 5so2252350wmb.1 for ; Mon, 25 Oct 2021 14:21:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:references:user-agent:in-reply-to :message-id:mime-version:content-transfer-encoding; bh=ONyz8A80Vkj2Jw9sKpY5z8jy0iNzQmzev+uX3V3mIhI=; b=p3CuGeGbCqD+A+NrwMWSB5ljyqBtEfIT+U7mIFEoaPmdX4sGqJbT3LBJJ4iRD+Ajih eb9e0veVoNzHWCrLMiBcbZTHjhrxqwnpcAKLTRMwQEyaV+JqWjueslNjtz7CbX9cUNjm 6SYrYU1AJb0WogXD/LbPI8Juhvo8H2NzDOPKT5NEayu9Nxh0bII02aqEjPXblUa8jgp1 DvMCkvwdS1XNyfxcrZijuC6u6dBCKtTWZ+0ttKvMWu9CFLVxE1kBS7whX5yUHaB8uxd+ xakhBRc0+Zn7TFx+I2GYJYool5FhtjV1NrvePTZiGzkkdjhXzU+3z1MXkxhU2uXhqsoj Ipcw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:references:user-agent :in-reply-to:message-id:mime-version:content-transfer-encoding; bh=ONyz8A80Vkj2Jw9sKpY5z8jy0iNzQmzev+uX3V3mIhI=; b=HNuOieoqErv/dEa9Cvvm5sCDon1fxjoJDRBL7O/wrYQx/HaOJktF8EC9LOx7nZcUXN sAXLXhAzumsgunoHHIFx58CFJP0Np3NSs6kiQZcnEnMk7CKI7K7ZUX9GmGB1eouhpnmi 3ZIftC2lCklwNl1d+i19gCrG6zmge68oQRwLwKegRuoGK7IganQU7t/7OYEZZ988hJP2 DMH/3ee0sj8ZYSbjVHec+YVD1lx4KoAit4kAeMxaSZLgp/BAsGPMkx5o0Ah2HZCKjLeA 4Qrt8+ER0a8OtHfTQWGsGw0XJiGG64xB7drp5HcUZ5fAKV5OIYG3XkWRrjUx1QgWlAkc bnAA== X-Gm-Message-State: AOAM532D6CvopAzlgN/RqPgGe8uSElRQLhhVLf60uU6yO6M5UY6rLXVm fG9RxWwOLTG6agBNXs9/jUs= X-Google-Smtp-Source: ABdhPJxMyeSjH9jWHqjmGmZ8oUPQhChA6LFZY4dZeFYcMNndtBY9lzdsns+HSbGds78GdPk8FJFV8Q== X-Received: by 2002:a05:600c:35cb:: with SMTP id r11mr2491502wmq.76.1635196904986; Mon, 25 Oct 2021 14:21:44 -0700 (PDT) Received: from gmgdl (j120189.upc-j.chello.nl. [24.132.120.189]) by smtp.gmail.com with ESMTPSA id q14sm19653517wmq.4.2021.10.25.14.21.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 25 Oct 2021 14:21:44 -0700 (PDT) Received: from avar by gmgdl with local (Exim 4.95) (envelope-from ) id 1mf7Pc-001fL7-0R; Mon, 25 Oct 2021 23:21:44 +0200 From: =?utf-8?B?w4Z2YXIgQXJuZmrDtnLDsA==?= Bjarmason To: Philip Oakley Cc: git@vger.kernel.org, Johannes Schindelin , Emily Shaffer Subject: Re: [Summit topic] Let's have chalk talks (part 1/?) Date: Mon, 25 Oct 2021 23:20:18 +0200 References: User-agent: Debian GNU/Linux bookworm/sid; Emacs 27.1; mu4e 1.6.6 In-reply-to: Message-ID: <211025.865ytk3imw.gmgdl@evledraar.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Mon, Oct 25 2021, Philip Oakley wrote: > On 22/10/2021 08:51, Johannes Schindelin wrote: >> Apparently I have to send this in chunks, to fool the Bayes filter of our >> beloved mailing list into doing The Right Thing. >> >> This session was led by Emily Shaffer. Supporting cast: =C3=86var Arnfj= =C3=B6r=C3=B0 >> Bjarmason, brian m. carlson, CB Bailey, and Junio Hamano. >> >> Notes: >> >> 1. What=E2=80=99s a public chalk talk? >> >> 1. At Google, once a week, the team meets up with no particular to= pic in >> mind, or a couple topics, very informal >> >> 2. One person=E2=80=99s turn each week to give an informal talk wi= th a white >> board (not using chalk) >> >> 3. Topic should be technical and of interest to the presenter > [...] > > A 'listener' perspective.. > > At the summit, the packfile's packing algorithm was mentioned as a > historic 'chalk talk' that's now in the technical documentation. > > In the meantime, while chatting to a colleague about the birthday > paradox and its relation to Bloom filters, I realised I didn't > understand what our Bloom filters were trying to do and what they recorde= d. > > I had a look at the code and documentation, but there isn't much there > about our Bloom filter implementation. A chalk talk could later be used > in the same manner as the packfile discussion to show what the filters do? > > If there is someone who'd like to talk through what the Bloom filters > are doing in Git then I'd be all ears. That sounds like a good idea for a topic, not to take away from any of that discussion, but I believe the bloom filters we have are exclusively used for path filtering if they exist in the commit-graph. I.e. for: git rev-list -- $path See c525ce95b46 (commit-graph: check all leading directories in changed path Bloom filters, 2020-07-01) for one use-case and benchmark numbers.