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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 42517C43331 for ; Tue, 24 Mar 2020 13:20:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1604D208DB for ; Tue, 24 Mar 2020 13:20:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585056019; bh=SKKMNxawj+JTG4PwVo9ZHSzlg0hcJb0jdQWP5yeJv6I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=dLuS0WCRk0G/v78mBFfXL8TtQqaz0RG2P7A455SsYqSTXSyBF+E/P7ualYddWF8Vh to2JN7+KtE3IITa1pgSAi2ud8mnZhXT9Z2sjaEsXULmSu1bTPuBHp4+E0MSwh5uWHk S1RyAc9JnhcRT1hOp4rM556ERQuqUj21eGcyxWzk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728919AbgCXNUR (ORCPT ); Tue, 24 Mar 2020 09:20:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:41410 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728140AbgCXNUO (ORCPT ); Tue, 24 Mar 2020 09:20:14 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8F2A920870; Tue, 24 Mar 2020 13:20:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585056014; bh=SKKMNxawj+JTG4PwVo9ZHSzlg0hcJb0jdQWP5yeJv6I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eaInU6RE5wTzHimRoGlBkBK4Q0VCn8dK1du4HKuzpY+2+dKK3rgLPro9gqcKd57cI xVCD3WUB6vr9F5ggSI82o93MCynL3S8L2xTT0FU5gELRcEsiGEOZhXJ4/siganns8r QXlKfxYUR7XJvq4rC7PD6Cm2LU+Y4N8w+VChkfvQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mark Wunderlich , Sagi Grimberg , Keith Busch Subject: [PATCH 5.4 099/102] nvmet-tcp: set MSG_MORE only if we actually have more to send Date: Tue, 24 Mar 2020 14:11:31 +0100 Message-Id: <20200324130816.773551496@linuxfoundation.org> X-Mailer: git-send-email 2.25.2 In-Reply-To: <20200324130806.544601211@linuxfoundation.org> References: <20200324130806.544601211@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sagi Grimberg commit 98fd5c723730f560e5bea919a64ac5b83d45eb72 upstream. When we send PDU data, we want to optimize the tcp stack operation if we have more data to send. So when we set MSG_MORE when: - We have more fragments coming in the batch, or - We have a more data to send in this PDU - We don't have a data digest trailer - We optimize with the SUCCESS flag and omit the NVMe completion (used if sq_head pointer update is disabled) This addresses a regression in QD=1 with SUCCESS flag optimization as we unconditionally set MSG_MORE when we didn't actually have more data to send. Fixes: 70583295388a ("nvmet-tcp: implement C2HData SUCCESS optimization") Reported-by: Mark Wunderlich Tested-by: Mark Wunderlich Signed-off-by: Sagi Grimberg Signed-off-by: Keith Busch Signed-off-by: Greg Kroah-Hartman --- drivers/nvme/target/tcp.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) --- a/drivers/nvme/target/tcp.c +++ b/drivers/nvme/target/tcp.c @@ -515,7 +515,7 @@ static int nvmet_try_send_data_pdu(struc return 1; } -static int nvmet_try_send_data(struct nvmet_tcp_cmd *cmd) +static int nvmet_try_send_data(struct nvmet_tcp_cmd *cmd, bool last_in_batch) { struct nvmet_tcp_queue *queue = cmd->queue; int ret; @@ -523,9 +523,15 @@ static int nvmet_try_send_data(struct nv while (cmd->cur_sg) { struct page *page = sg_page(cmd->cur_sg); u32 left = cmd->cur_sg->length - cmd->offset; + int flags = MSG_DONTWAIT; + + if ((!last_in_batch && cmd->queue->send_list_len) || + cmd->wbytes_done + left < cmd->req.transfer_len || + queue->data_digest || !queue->nvme_sq.sqhd_disabled) + flags |= MSG_MORE; ret = kernel_sendpage(cmd->queue->sock, page, cmd->offset, - left, MSG_DONTWAIT | MSG_MORE); + left, flags); if (ret <= 0) return ret; @@ -660,7 +666,7 @@ static int nvmet_tcp_try_send_one(struct } if (cmd->state == NVMET_TCP_SEND_DATA) { - ret = nvmet_try_send_data(cmd); + ret = nvmet_try_send_data(cmd, last_in_batch); if (ret <= 0) goto done_send; }