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-Status: No, score=-3.7 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,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 C23FC1F9FD for ; Thu, 25 Feb 2021 07:59:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235365AbhBYH6e (ORCPT ); Thu, 25 Feb 2021 02:58:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54320 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235338AbhBYH63 (ORCPT ); Thu, 25 Feb 2021 02:58:29 -0500 Received: from mail-lj1-x22f.google.com (mail-lj1-x22f.google.com [IPv6:2a00:1450:4864:20::22f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2B441C061788 for ; Wed, 24 Feb 2021 23:57:49 -0800 (PST) Received: by mail-lj1-x22f.google.com with SMTP id u4so5410257ljh.6 for ; Wed, 24 Feb 2021 23:57:49 -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=NF8jm0DLpgaMGyeDm7FqmiwtgLdS2HrDrzj3pZzXUzg=; b=IRvy+sr19p+C0Nk4YqovBlXGUtMP1/PcUD8dUslo3gupU5wN7Cx2X08KWekoG3b2YE QCyuGu+Dl+0h+Zbmq6C1IdDqXv1qOw3HTbxlLecD85eGejM8xKU2fD8Xsw3zaEXE1XRp CS/uY2eRgaiNgAIdmk56SOLomzfu2YzTm4XhXvE9int8YM89QLyzbpK+XgsFItvniogC pPszOro/TrUKS+FFVDLbvwnQ2hWtXv0ufyr4zNCRgesHa/3N4PawTp3r1/n/5Gle8YBt e83gGLZBmP6s3DH4IEcv9ilq9xCyrgurt8scL9J0+MwCppmGpjpc2LzCerPdj0TNHU/Y kVUA== 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=NF8jm0DLpgaMGyeDm7FqmiwtgLdS2HrDrzj3pZzXUzg=; b=Y15qhehsLu2uwhCdYQt+h5XRm4AhzTMgou4gdAX9v1c6x8vilGX8fmv8g08RtrxZRj UjLi3+wkuDGuXv+Iwwi3nJCjd0TqFPnA1NEW55h/g5L+Io561tCGA4tm/J7T5EWfVwjI /lgxbCrBxrJNTySSiroVrX3Cp8fcJ1z1n9M9YsJorV0H5+LMNDdqH4w3XOw44OOBx0ZV UFua5oZatgS6CMBZYcRvTRGxOuuU5TWhhq9m3noBVM36fxtPvpHJj59XPJOXu2WMT0te xi3uwuvOj9sqjE71rgHgY7vFaStp4ACBzilGla+AMFTEGvx+ZKGmTNbhAgzxxob6p3+w 7EpA== X-Gm-Message-State: AOAM532XP3zmrtO2AVxHpbvmG8x3NsEA/5t2poo9eQAzWFULTHgLRffX bgl9bw7I/SVVg5wtNUpvbTZ07m+3JeZeMCiOYj8= X-Google-Smtp-Source: ABdhPJzC9KhFl35GzW4t37y/oON67n8AvDnRka/im9mEpc0pw8rS0efIaFx9m2KHhQYp0MvONk8aKzpnjzpQwwP864U= X-Received: by 2002:a2e:b81a:: with SMTP id u26mr942229ljo.434.1614239867735; Wed, 24 Feb 2021 23:57:47 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Chris Torek Date: Wed, 24 Feb 2021 23:57:36 -0800 Message-ID: Subject: Re: [PATCH] read-cache: make the index write buffer size 128K To: Neeraj Singh Cc: Junio C Hamano , Jeff Hostetler , Git List , "Neeraj K. Singh" Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Wed, Feb 24, 2021 at 11:36 PM Neeraj Singh wrote: > From a quick perusal of freebsd, st_blksize seems to be the system > PAGE_SIZE by default (4k most of the time, I assume). The Windows > equivalent of this value is really tuned to what you want to send down > when bypassing the cache (to avoid partial cluster/stripe writes). It's page-size for pipes, sockets, etc., but for real files, it's based on a report from the underlying file system. It's actually 8k on a typical ancient UFS file system, 64K on UFS2, and 128K on ZFS, on FreeBSD. > https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_stat.h.html > doesn't elicit much confidence. The units of st_blksize aren't even > defined. Despite POSIX's rather obstreperous definition of st_blksize, the units are actually just bytes, in practice. Chris