From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 31B931E1AC for ; Thu, 10 Aug 2023 14:04:22 +0000 (UTC) Received: from mail-qv1-xf33.google.com (mail-qv1-xf33.google.com [IPv6:2607:f8b0:4864:20::f33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5910426A9; Thu, 10 Aug 2023 07:04:21 -0700 (PDT) Received: by mail-qv1-xf33.google.com with SMTP id 6a1803df08f44-63d30554eefso5881376d6.3; Thu, 10 Aug 2023 07:04:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1691676260; x=1692281060; h=content-transfer-encoding:mime-version:subject:references :in-reply-to:message-id:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=Bvw8YvdgNBQrpsheEQ2rQUvV3iq1U97lLZrULuXMDMs=; b=MT6tgtnaPVBnDX1/jqNuZTikjkdy/v7dbMQcgYVXfQDEneiPJDdbLoAi6RSDSyYZLe Yz5fdQuOkXLbFf+CREPHQBav9P9kC/lwhAANwrnpV0ROj/Sl2shYVSPsQ+/3XXM1Ng6b 5yg+GrasWSnc5Kcx1QWDEPNf/OpoFcqEGwfp6eUN8FxEy7KLdP5mq1JxTfl46p3X+wTx HV421oyUX6EPdNboTTA3tCFOFsJb3pTOlITfzEJoMolSkV/Wiyqw6tX6H2G0knKW9dD9 we2RbbGuYvti3h0t3Yoxcdx3TjBi8m7cZl8idxX0lCVctcK21cBote/q1c5mmgRvcw6f /kgA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691676260; x=1692281060; h=content-transfer-encoding:mime-version:subject:references :in-reply-to:message-id:cc:to:from:date:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=Bvw8YvdgNBQrpsheEQ2rQUvV3iq1U97lLZrULuXMDMs=; b=b2xtVHdI4n5m4lmDdh1AWvbNcKBNE1wvnt0L558lryVfZTzmMWTMXRe3E++YcH2kbL SWIeHMqrEYixGKkF98Kyk/lxhcBYozdQocF39Kcdj2huBTWgmlnfURiYTz7y+23JSjS4 QCBi9fAgi30LyLW9JqjFmx6Me2WP5jisgWChb4/63L7mX4aIDfLguN9g2qve+RYCk5QO +dwm5wWOuSy5vA3R6qCidmP5ASDhQOQYjriqLLskSYSzmiwY9UTZYPOMrjl5SnDUQsiv EoxeT0iLXd8MRiA81ml8I5lfKhMmawrgvyRj0B2DKER/c1fxE9FwfHw5101ck0LZHb1r Q0+w== X-Gm-Message-State: AOJu0Yxlvc4v0WrN4J50UNeZcj6jc1e+VocgKJkE0WdKO9+SqPOFxi3N vRl4ZfTbqbWOt4GORCf4LSg= X-Google-Smtp-Source: AGHT+IEa19gHa+xwfMPcikqOiNgjQXbBoYvmyyHFcu3B3sagWhL9r8l0C0lLB86O9aTgEoSci5WBhw== X-Received: by 2002:a05:6214:5283:b0:639:91ad:64d6 with SMTP id kj3-20020a056214528300b0063991ad64d6mr2357058qvb.61.1691676260347; Thu, 10 Aug 2023 07:04:20 -0700 (PDT) Received: from localhost (172.174.245.35.bc.googleusercontent.com. [35.245.174.172]) by smtp.gmail.com with ESMTPSA id d5-20020a0cdb05000000b0062b76c29978sm504864qvk.6.2023.08.10.07.04.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Aug 2023 07:04:19 -0700 (PDT) Date: Thu, 10 Aug 2023 10:04:19 -0400 From: Willem de Bruijn To: Tahsin Erdogan , Willem de Bruijn , Jason Wang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Herbert Xu Cc: Tahsin Erdogan , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Message-ID: <64d4ee63a11e9_8e54c294a9@willemb.c.googlers.com.notmuch> In-Reply-To: <20230809164753.2247594-1-trdgn@amazon.com> References: <20230809164753.2247594-1-trdgn@amazon.com> Subject: Re: [PATCH v4] tun: avoid high-order page allocation for packet header Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Tahsin Erdogan wrote: > When gso.hdr_len is zero and a packet is transmitted via write() or > writev(), all payload is treated as header which requires a contiguous > memory allocation. This allocation request is harder to satisfy, and may > even fail if there is enough fragmentation. > > Note that sendmsg() code path limits the linear copy length, so this change > makes write()/writev() and sendmsg() paths more consistent. > > Signed-off-by: Tahsin Erdogan Reviewed-by: Willem de Bruijn