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=-10.1 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,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 E2536C2D0DB for ; Fri, 24 Jan 2020 14:28:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B680821734 for ; Fri, 24 Jan 2020 14:28:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579876137; bh=nszOQlWLNn/SKVu+on/hSsf4EZcpBiQzfO0wSwc/1Nc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=whd8RrNl2Uccy437NsD1Vf9ITcbukTkS47xyUYfzBmXqhrHqmVKIo8nvNrQ+hKmrT AFQkv0FpxwWhJ4Yy/+XozOwvIKBlyhaawa9VfjenwLg7MEnfjyPTs1vWHdiho+UUoo GjoGiBInDBGPSvn/x7NamZ487wcizLa5E4qa0j7k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392184AbgAXOVD (ORCPT ); Fri, 24 Jan 2020 09:21:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:42516 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392177AbgAXOVD (ORCPT ); Fri, 24 Jan 2020 09:21:03 -0500 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 16FA42077C; Fri, 24 Jan 2020 14:21:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579875662; bh=nszOQlWLNn/SKVu+on/hSsf4EZcpBiQzfO0wSwc/1Nc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WBGnJZaUCulJ8b9C6qRsQl0MdLC1Rd4BEToIvVBli0J+6uAL1gCRgq1uQgtjku2D2 6dNNGdBlctRbl51tsFL9+1QekuAUqmVRiMvN6agD0+wweTEP0CRB0e+scbujgji2oD d6SJc2nKCs37c0hFGdz+Td/mQh0WoUVrdDmsC2oU= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Petr Machata , Jiri Pirko , Ido Schimmel , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 43/56] mlxsw: spectrum: Wipe xstats.backlog of down ports Date: Fri, 24 Jan 2020 09:19:59 -0500 Message-Id: <20200124142012.29752-43-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200124142012.29752-1-sashal@kernel.org> References: <20200124142012.29752-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Petr Machata [ Upstream commit ca7609ff3680c51d6c29897f3117aa2ad904f92a ] Per-port counter cache used by Qdiscs is updated periodically, unless the port is down. The fact that the cache is not updated for down ports is no problem for most counters, which are relative in nature. However, backlog is absolute in nature, and if there is a non-zero value in the cache around the time that the port goes down, that value just stays there. This value then leaks to offloaded Qdiscs that report non-zero backlog even if there (obviously) is no traffic. The HW does not keep backlog of a downed port, so do likewise: as the port goes down, wipe the backlog value from xstats. Fixes: 075ab8adaf4e ("mlxsw: spectrum: Collect tclass related stats periodically") Signed-off-by: Petr Machata Acked-by: Jiri Pirko Signed-off-by: Ido Schimmel Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/mellanox/mlxsw/spectrum.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c index e498ee95bacab..30ef318b3d68d 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c @@ -1061,6 +1061,9 @@ static void update_stats_cache(struct work_struct *work) periodic_hw_stats.update_dw.work); if (!netif_carrier_ok(mlxsw_sp_port->dev)) + /* Note: mlxsw_sp_port_down_wipe_counters() clears the cache as + * necessary when port goes down. + */ goto out; mlxsw_sp_port_get_hw_stats(mlxsw_sp_port->dev, @@ -3309,6 +3312,15 @@ static int mlxsw_sp_port_unsplit(struct mlxsw_core *mlxsw_core, u8 local_port, return 0; } +static void +mlxsw_sp_port_down_wipe_counters(struct mlxsw_sp_port *mlxsw_sp_port) +{ + int i; + + for (i = 0; i < TC_MAX_QUEUE; i++) + mlxsw_sp_port->periodic_hw_stats.xstats.backlog[i] = 0; +} + static void mlxsw_sp_pude_event_func(const struct mlxsw_reg_info *reg, char *pude_pl, void *priv) { @@ -3329,6 +3341,7 @@ static void mlxsw_sp_pude_event_func(const struct mlxsw_reg_info *reg, } else { netdev_info(mlxsw_sp_port->dev, "link down\n"); netif_carrier_off(mlxsw_sp_port->dev); + mlxsw_sp_port_down_wipe_counters(mlxsw_sp_port); } } -- 2.20.1