From patchwork Tue Mar 3 17:41:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 229913 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, 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 8F0FDC3F2C6 for ; Tue, 3 Mar 2020 18:08:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6B69B2073B for ; Tue, 3 Mar 2020 18:08:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583258903; bh=RvQhxzX6sNPG//i4+vk6Vu4eK5JycpXVfhLLiIG7OWM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=jrUFUZ6LhxzDXZp6F2r15yMRRiuEEbbixyFE5CK5ZlpmrMg3GuQQdkIK6S8q0IULO /hVIQXmsMiEOhra3ubpd4u92thxZvftlTBD7R1xHspLixFxJIQ+X97wRYXibeXPPIO xXWJdRDfZ+mtJFdGoWbRgg/Gq9+GF0ytyaqSAZCs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733259AbgCCSIW (ORCPT ); Tue, 3 Mar 2020 13:08:22 -0500 Received: from mail.kernel.org ([198.145.29.99]:34278 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729318AbgCCRxj (ORCPT ); Tue, 3 Mar 2020 12:53:39 -0500 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 CD860206D5; Tue, 3 Mar 2020 17:53:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583258018; bh=RvQhxzX6sNPG//i4+vk6Vu4eK5JycpXVfhLLiIG7OWM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V93xFb259SAflWIsGKUC0X7Mamk+uxuD74LhwVAfDb+zMP4rrNyTFzEtCLQzys2b+ oqBl4WEe3fKjY/7spBbzppwi06UT9L3yaw4UzlaSPEst8TM407eQ6UxdCwxaxKc3AI By1biQoJQ9ISx+D+lmspuiFrSODsvJ30jLCJ/ymI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ahmad Fatoum , Paolo Abeni , "David S. Miller" Subject: [PATCH 5.4 012/152] Revert "net: dev: introduce support for sch BYPASS for lockless qdisc" Date: Tue, 3 Mar 2020 18:41:50 +0100 Message-Id: <20200303174303.899277587@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200303174302.523080016@linuxfoundation.org> References: <20200303174302.523080016@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Paolo Abeni [ Upstream commit 379349e9bc3b42b8b2f8f7a03f64a97623fff323 ] This reverts commit ba27b4cdaaa66561aaedb2101876e563738d36fe Ahmed reported ouf-of-order issues bisected to commit ba27b4cdaaa6 ("net: dev: introduce support for sch BYPASS for lockless qdisc"). I can't find any working solution other than a plain revert. This will introduce some minor performance regressions for pfifo_fast qdisc. I plan to address them in net-next with more indirect call wrapper boilerplate for qdiscs. Reported-by: Ahmad Fatoum Fixes: ba27b4cdaaa6 ("net: dev: introduce support for sch BYPASS for lockless qdisc") Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/core/dev.c | 22 ++-------------------- 1 file changed, 2 insertions(+), 20 deletions(-) --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3386,26 +3386,8 @@ static inline int __dev_xmit_skb(struct qdisc_calculate_pkt_len(skb, q); if (q->flags & TCQ_F_NOLOCK) { - if ((q->flags & TCQ_F_CAN_BYPASS) && READ_ONCE(q->empty) && - qdisc_run_begin(q)) { - if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, - &q->state))) { - __qdisc_drop(skb, &to_free); - rc = NET_XMIT_DROP; - goto end_run; - } - qdisc_bstats_cpu_update(q, skb); - - rc = NET_XMIT_SUCCESS; - if (sch_direct_xmit(skb, q, dev, txq, NULL, true)) - __qdisc_run(q); - -end_run: - qdisc_run_end(q); - } else { - rc = q->enqueue(skb, q, &to_free) & NET_XMIT_MASK; - qdisc_run(q); - } + rc = q->enqueue(skb, q, &to_free) & NET_XMIT_MASK; + qdisc_run(q); if (unlikely(to_free)) kfree_skb_list(to_free);