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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 18DF1C282DC for ; Wed, 22 May 2019 19:49:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD09720862 for ; Wed, 22 May 2019 19:49:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558554577; bh=OPj4hyP2iivzFkdQtG2vtTeYaImKjX+wHPT3oJiMBX8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=rLv7dvjUUrRi4JNpHk1hwRtbE60760TMcLqf8FZ5X12MB+j+KIJxy1FQslEMY0TRT 9FHNU+Eg13ooqaKBiym9Fo62vz6uZaRMK7uWTNxrP3lwcwxbSwKBjRX+YvYBD8zzjY P1JoubRMtP4OidhdF2BuO4XXCC9kS1ihouiG+a6w= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730522AbfEVT0w (ORCPT ); Wed, 22 May 2019 15:26:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:48520 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732148AbfEVT0u (ORCPT ); Wed, 22 May 2019 15:26:50 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E4E97217F9; Wed, 22 May 2019 19:26:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558553209; bh=OPj4hyP2iivzFkdQtG2vtTeYaImKjX+wHPT3oJiMBX8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jz5kAajdS9PJfdusH0fHOm1UHCMOPv97p1XZb6+V8pb6E/f7K+yO+HLZXCFeTPabK NiGTFIUKxMsNhMqh3E0BfetINBRhnNolDt3ub56f9OeJfxr+OtI5yEwVJpqdN42Chy 8jGCt1rUhVxFV/kFfwIC59dUu5E/4MSQ3lg84HBk= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Haiyang Zhang , Stephan Klein , "David S . Miller" , Sasha Levin , linux-hyperv@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 013/244] hv_netvsc: fix race that may miss tx queue wakeup Date: Wed, 22 May 2019 15:22:39 -0400 Message-Id: <20190522192630.24917-13-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190522192630.24917-1-sashal@kernel.org> References: <20190522192630.24917-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Haiyang Zhang [ Upstream commit 93aa4792c3908eac87ddd368ee0fe0564148232b ] When the ring buffer is almost full due to RX completion messages, a TX packet may reach the "low watermark" and cause the queue stopped. If the TX completion arrives earlier than queue stopping, the wakeup may be missed. This patch moves the check for the last pending packet to cover both EAGAIN and success cases, so the queue will be reliably waked up when necessary. Reported-and-tested-by: Stephan Klein Signed-off-by: Haiyang Zhang Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/hyperv/netvsc.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c index fb12b63439c67..35413041dcf81 100644 --- a/drivers/net/hyperv/netvsc.c +++ b/drivers/net/hyperv/netvsc.c @@ -872,12 +872,6 @@ static inline int netvsc_send_pkt( } else if (ret == -EAGAIN) { netif_tx_stop_queue(txq); ndev_ctx->eth_stats.stop_queue++; - if (atomic_read(&nvchan->queue_sends) < 1 && - !net_device->tx_disable) { - netif_tx_wake_queue(txq); - ndev_ctx->eth_stats.wake_queue++; - ret = -ENOSPC; - } } else { netdev_err(ndev, "Unable to send packet pages %u len %u, ret %d\n", @@ -885,6 +879,15 @@ static inline int netvsc_send_pkt( ret); } + if (netif_tx_queue_stopped(txq) && + atomic_read(&nvchan->queue_sends) < 1 && + !net_device->tx_disable) { + netif_tx_wake_queue(txq); + ndev_ctx->eth_stats.wake_queue++; + if (ret == -EAGAIN) + ret = -ENOSPC; + } + return ret; } -- 2.20.1