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=-4.4 required=3.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 7F19D1F953 for ; Wed, 15 Dec 2021 20:45:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231992AbhLOUpc (ORCPT ); Wed, 15 Dec 2021 15:45:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55012 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229452AbhLOUpb (ORCPT ); Wed, 15 Dec 2021 15:45:31 -0500 Received: from mail-qv1-xf36.google.com (mail-qv1-xf36.google.com [IPv6:2607:f8b0:4864:20::f36]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 240EDC061574 for ; Wed, 15 Dec 2021 12:45:31 -0800 (PST) Received: by mail-qv1-xf36.google.com with SMTP id b11so21429568qvm.7 for ; Wed, 15 Dec 2021 12:45:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gitlab.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=+2/eM47BJiSzUyC4WwfyMybc3m5BfBdb1YU9A1xP8w8=; b=KGfXNLUlPH+dh6zz5X5elLcHLJBpbmBD5QNBfptj4y/A8J1uabTgA4hxCHvR5mAwSa iOkxOrVGNMStAQ/45ZEJ82lRpYCyVkvSNgUcPrp/SrYj8F9bZ91OM18ssl+d9Vl1Uh5s UrABD5/d7Pwp0NRkScocMYSvA2dScSxyYTzHc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=+2/eM47BJiSzUyC4WwfyMybc3m5BfBdb1YU9A1xP8w8=; b=q3I46H5LSoqTYUwGjufsorBJbOm8MJ1ETrc6fAbp4EF+KByzt9cETBYUCi8kuicEO3 HxBjUTrYYKtFwfqncWbfujcRvzoHf2AvMeRay3rv7ZQnQnXR8cD+cZex++9/e1TcWZwW gxIu4PUv3ROhSlNsX+4D3/DoFjtl95nsyWPsEZ8slu/SH5xzCLS/KU1fuoo1hw/8rOdE o8fGDzrNsg2+OAG4x18foUTCLIButayeYYN4B14xmmIEM5DXX/mgIyCBAxleUBgCri25 M2W1AUe1+Z58p4bL5a9LjaIPULS9LglpqX5wBuUuaBKmNKowC+dO3t8FtTgBK48d4V6R zqrw== X-Gm-Message-State: AOAM531V7jk2hZvlEO+WtHuJ+B18g9maXQjBOOpCvL5ZWdg3aIS/ckuQ LEY2V0myKIP8Zcw51ucqARoVy6uS85Ou9c/y9ex/pQ== X-Google-Smtp-Source: ABdhPJzr4sjNDiJQyz1OsjtXyZZOCNM9tIXE+uket3SbM0OuXeHbC5wx0OldxucbCssDuUuaeLaHe+UpvNcI87Rl8aE= X-Received: by 2002:a05:6214:27ee:: with SMTP id jt14mr13067643qvb.5.1639601130303; Wed, 15 Dec 2021 12:45:30 -0800 (PST) MIME-Version: 1.0 References: <20211214194626.33814-1-jacob@gitlab.com> <20211214194626.33814-2-jacob@gitlab.com> <003001d7f1ee$48c88410$da598c30$@nexbridge.com> <003301d7f1f3$c1e24f20$45a6ed60$@nexbridge.com> In-Reply-To: <003301d7f1f3$c1e24f20$45a6ed60$@nexbridge.com> From: Jacob Vosmaer Date: Wed, 15 Dec 2021 21:45:19 +0100 Message-ID: Subject: Re: [PATCH v2 1/1] upload-pack.c: increase output buffer size To: rsbecker@nexbridge.com Cc: Junio C Hamano , git@vger.kernel.org, avarab@gmail.com, peff@peff.net Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Wed, Dec 15, 2021 at 9:38 PM wrote: > > The maximum I/O size on the platform is 56Kb. Anything larger will fail. That's why we use xread and xwrite for non-buffered I/O. That sounds like it's orthogonal to what this patch is changing. Regardless of this patch, the actual writes are performed by write_or_die, which calls write_in_full. In turn, write_in_full calls xwrite however often is necessary. We are not making any assumptions anywhere about how large individual write syscalls turn out. Git packets use userspace buffers so we can read and write them no matter what the underlying IO sizes are.