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 X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 46E35C47254 for ; Tue, 5 May 2020 10:24:05 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1DBAC20675 for ; Tue, 5 May 2020 10:24:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="h+lzVVOb" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1DBAC20675 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=0Oz/PXhEY9BaX/JRXswdfo9/q8v9Odd89SEicTkDRRo=; b=h+lzVVObzI7/z1 s3LBww2EBS6nQRvQ2BbFr2OWKYR67vd2ZrEc6l3muVT0NOKQkrDwglqwyy2/xsJsAOFsFroljqBoD erNq2hKg9AHHcEo8JrFm2GlFjOScrCKR0yiSqLk4g7re8nqwsyha0q1IKatS9R991aOeGetPRN3Dh 2NDXoFh/mJLm+SkJLFYY74Mfie/pti2lNmAvsmIjz9iSmCPshdUwoIPS4OH3MoDWflmaEVbTZ8QGh k1nPjYjbOuV7dIdcT3CBhARqAonN0f6V17pLbR+WrKls2yeA1xmreawFOPw8VXu6fYl7yVMRTuZMe AOoNw1SCZ7cukvn1q4cw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jVuk4-0002xh-4Y; Tue, 05 May 2020 10:24:00 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jVuk1-0002xG-LJ for linux-nvme@lists.infradead.org; Tue, 05 May 2020 10:23:58 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id AA65368C65; Tue, 5 May 2020 12:23:55 +0200 (CEST) Date: Tue, 5 May 2020 12:23:54 +0200 From: Christoph Hellwig To: Sagi Grimberg Subject: Re: [PATCH 1/2] nvme-tcp: set MSG_SENDPAGE_NOTLAST with MSG_MORE when we have more to send Message-ID: <20200505102354.GB15038@lst.de> References: <20200505052002.14924-1-sagi@grimberg.me> <20200505060907.GA3995@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200505_032357_850093_248F0375 X-CRM114-Status: GOOD ( 13.92 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Keith Busch , Mark Wunderlich , Anil Vasudevan , Christoph Hellwig , linux-nvme@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Mon, May 04, 2020 at 11:50:57PM -0700, Sagi Grimberg wrote: > >>> We can signal the stack that this is not the last page coming and the >>> stack can build a larger tso segment, so go ahead and use it. >> >> Maybe you wan a little helper that returns the flags based on a last >> flag? Something like: >> >> static int nvme_tcp_msg_flags(bool last_page) >> { >> if (last_page) >> return MSG_DONTWAIT | MSG_MORE | MSG_SENDPAGE_NOTLAST; >> return MSG_DONTWAIT | MSG_EOR; >> } > > You have it reversed, the flag here probably means more... > > Let me see if it is useful to have, will let you know... > >> >> or do we have a case where we don't want to set EOR? At least the >> target seems to currently have such a case. > > As a design goal, we try to tell the stack explicitly if we have more > to send and if not we want to push it down to reduce latency. So > I think we need to have it in the target as well. What I mean is that nvmet_try_send_data and nvmet_try_send_ddgst may set neither MS_MORE nor MSG_EOR. Is that intentional? _______________________________________________ linux-nvme mailing list linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme