From patchwork Fri Jun 18 12:09:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "huangguangbin \(A\)" X-Patchwork-Id: 463741 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, 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 BF0F8C48BDF for ; Fri, 18 Jun 2021 12:13:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 999A1613E9 for ; Fri, 18 Jun 2021 12:13:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233235AbhFRMPL (ORCPT ); Fri, 18 Jun 2021 08:15:11 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:7489 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231250AbhFRMPL (ORCPT ); Fri, 18 Jun 2021 08:15:11 -0400 Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.55]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4G5yRG4hrzzZjjq; Fri, 18 Jun 2021 20:10:02 +0800 (CST) Received: from dggemi759-chm.china.huawei.com (10.1.198.145) by dggemv711-chm.china.huawei.com (10.1.198.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2176.2; Fri, 18 Jun 2021 20:12:58 +0800 Received: from localhost.localdomain (10.67.165.24) by dggemi759-chm.china.huawei.com (10.1.198.145) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Fri, 18 Jun 2021 20:12:58 +0800 From: Guangbin Huang To: , CC: , , , , Subject: [PATCH net-next] net: hns3: fix reuse conflict of the rx page Date: Fri, 18 Jun 2021 20:09:45 +0800 Message-ID: <1624018185-38469-1-git-send-email-huangguangbin2@huawei.com> X-Mailer: git-send-email 2.8.1 MIME-Version: 1.0 X-Originating-IP: [10.67.165.24] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggemi759-chm.china.huawei.com (10.1.198.145) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Yunsheng Lin In the current rx page reuse handling process, the rx page buffer may have conflict between driver and stack in high-pressure scenario. To fix this problem, we need to check whether the page is only owned by driver at the begin and at the end of a page to make sure there is no reuse conflict between driver and stack when desc_cb->page_offset is rollbacked to zero or increased. Fixes: fa7711b888f2 ("net: hns3: optimize the rx page reuse handling process") Signed-off-by: Yunsheng Lin Signed-off-by: Guangbin Huang --- drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 26 ++++++++++++++++++------- 1 file changed, 19 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c index 51bbf5f760c5..cdb5f14fb6bc 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c @@ -3537,21 +3537,33 @@ static void hns3_nic_reuse_page(struct sk_buff *skb, int i, int size = le16_to_cpu(desc->rx.size); u32 truesize = hns3_buf_size(ring); u32 frag_size = size - pull_len; + bool reused; /* Avoid re-using remote or pfmem page */ if (unlikely(!dev_page_is_reusable(desc_cb->priv))) goto out; - /* Stack is not using and current page_offset is non-zero, we can - * reuse from the zero offset. + reused = hns3_can_reuse_page(desc_cb); + + /* Rx page can be reused when: + * 1. Rx page is only owned by the driver when page_offset + * is zero, which means 0 @ truesize will be used by + * stack after skb_add_rx_frag() is called, and the rest + * of rx page can be reused by driver. + * Or + * 2. Rx page is only owned by the driver when page_offset + * is non-zero, which means page_offset @ truesize will + * be used by stack after skb_add_rx_frag() is called, + * and 0 @ truesize can be reused by driver. */ - if (desc_cb->page_offset && hns3_can_reuse_page(desc_cb)) { - desc_cb->page_offset = 0; - desc_cb->reuse_flag = 1; - } else if (desc_cb->page_offset + truesize * 2 <= - hns3_page_size(ring)) { + if ((!desc_cb->page_offset && reused) || + ((desc_cb->page_offset + truesize + truesize) <= + hns3_page_size(ring) && desc_cb->page_offset)) { desc_cb->page_offset += truesize; desc_cb->reuse_flag = 1; + } else if (desc_cb->page_offset && reused) { + desc_cb->page_offset = 0; + desc_cb->reuse_flag = 1; } else if (frag_size <= ring->rx_copybreak) { void *frag = napi_alloc_frag(frag_size);