From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E9053C43334 for ; Tue, 12 Jul 2022 23:05:43 +0000 (UTC) Received: from localhost ([::1]:60378 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oBOwo-0001zv-Tg for qemu-devel@archiver.kernel.org; Tue, 12 Jul 2022 19:05:42 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50612) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oBOWf-0004QD-K7 for qemu-devel@nongnu.org; Tue, 12 Jul 2022 18:38:41 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:44451) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oBOWP-000554-K9 for qemu-devel@nongnu.org; Tue, 12 Jul 2022 18:38:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1657665501; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=F3SLJWQ6ZTWHTWfYbzqeqwqgxsn1JANpNhROR3s70TU=; b=VgqfGg/NhJAQXV5ZZOhULG1fjerqRZfm+Qvx5fnYHwAWu26OEX06C07ZZY0mveVUSfVgnc QA+GPU2HotBhokoGNEIlNgiExcY5O77x8rGzQl8NhopDUuY6HawT1qCHjrhuHCOZ7GAWBA eDQ6dRkY2s93A2F44ffSE+PgI2rRtdM= Received: from mail-qk1-f199.google.com (mail-qk1-f199.google.com [209.85.222.199]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-550-UgBGRnZ1M3SZN9Tc1cgCUQ-1; Tue, 12 Jul 2022 18:38:20 -0400 X-MC-Unique: UgBGRnZ1M3SZN9Tc1cgCUQ-1 Received: by mail-qk1-f199.google.com with SMTP id x22-20020a05620a259600b006b552a69231so8795871qko.18 for ; Tue, 12 Jul 2022 15:38:20 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=F3SLJWQ6ZTWHTWfYbzqeqwqgxsn1JANpNhROR3s70TU=; b=w4FJxZHXXvM9xJx7sC9CQ4QyVVIQwLUIp9Qzj4ytZ84+iGJdXZ52iAbc4vlfW9lhfn H0+jNG7EwinzeazeXl6ynIoPCWWa92eVSdnMQQBogRwK+cduhRnrOtK4tfMSat3JqpFa lbCZIDYTf+O63j348IIry7xyaBuzjj/kPuriwIClSY4MyovIWBRWstHNqMUhx5MUU2qj 84XJv0RkH1lDGgiV0VKz0salQU/hPX82ycnZk48khrY87zkUPZNMDKrzh1ZZPlprBVLR duqtxnAQ5pySkWigXjcqFnTp0CJsNxJPGeUzTQZfxn5D5ps1fE/s1nzvo0OTdkCCNokz rnqQ== X-Gm-Message-State: AJIora9haH8/ECFPOQFlE5dby82eDFiA0z/73ARPSch7VwA1kFUw2kMZ Qrzav6TSnKfldmrTjqBAWWYBMdBw/I+t8jo83yOMDfPQQ2inbDR7+DiImSzlu+uzcyG5EpR0Ouq oTHLu7kLF420leu8= X-Received: by 2002:ad4:5de8:0:b0:473:8d62:d2db with SMTP id jn8-20020ad45de8000000b004738d62d2dbmr507540qvb.112.1657665499761; Tue, 12 Jul 2022 15:38:19 -0700 (PDT) X-Google-Smtp-Source: AGRyM1vJjVhO33uWCZgagyEHU7n8fgTtrc5EW2hfh6QSC89gviPt9IoFmq/fRE1Vy6LZsJacYoj33A== X-Received: by 2002:ad4:5de8:0:b0:473:8d62:d2db with SMTP id jn8-20020ad45de8000000b004738d62d2dbmr507527qvb.112.1657665499573; Tue, 12 Jul 2022 15:38:19 -0700 (PDT) Received: from xz-m1.local (bras-base-aurron9127w-grc-37-74-12-30-48.dsl.bell.ca. [74.12.30.48]) by smtp.gmail.com with ESMTPSA id h9-20020a05620a244900b006af59e9ddeasm10252634qkn.18.2022.07.12.15.38.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 Jul 2022 15:38:18 -0700 (PDT) Date: Tue, 12 Jul 2022 18:38:17 -0400 From: Peter Xu To: Leonardo Bras Cc: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= , Juan Quintela , "Dr. David Alan Gilbert" , Eric Blake , Markus Armbruster , qemu-devel@nongnu.org Subject: Re: [PATCH v4 1/3] QIOChannelSocket: Fix zero-copy flush returning code 1 when nothing sent Message-ID: References: <20220711211112.18951-1-leobras@redhat.com> <20220711211112.18951-2-leobras@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220711211112.18951-2-leobras@redhat.com> Received-SPF: pass client-ip=170.10.133.124; envelope-from=peterx@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01, T_SPF_HELO_TEMPERROR=0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Jul 11, 2022 at 06:11:11PM -0300, Leonardo Bras wrote: > If flush is called when no buffer was sent with MSG_ZEROCOPY, it currently > returns 1. This return code should be used only when Linux fails to use > MSG_ZEROCOPY on a lot of sendmsg(). > > Fix this by returning early from flush if no sendmsg(...,MSG_ZEROCOPY) > was attempted. > > Fixes: 2bc58ffc2926 ("QIOChannelSocket: Implement io_writev zero copy flag & io_flush for CONFIG_LINUX") > Signed-off-by: Leonardo Bras > Reviewed-by: Daniel P. Berrangé > Acked-by: Daniel P. Berrangé > Reviewed-by: Juan Quintela Reviewed-by: Peter Xu -- Peter Xu