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=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 AB8E0C432C3 for ; Wed, 27 Nov 2019 07:47:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 82F272071E for ; Wed, 27 Nov 2019 07:47:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=dlink.ru header.i=@dlink.ru header.b="n0zd+O3r" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726512AbfK0Hrl (ORCPT ); Wed, 27 Nov 2019 02:47:41 -0500 Received: from mail.dlink.ru ([178.170.168.18]:51026 "EHLO fd.dlink.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726125AbfK0Hrk (ORCPT ); Wed, 27 Nov 2019 02:47:40 -0500 Received: by fd.dlink.ru (Postfix, from userid 5000) id 99C011B213A7; Wed, 27 Nov 2019 10:47:36 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 fd.dlink.ru 99C011B213A7 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dlink.ru; s=mail; t=1574840856; bh=kPCincx6WXgTjBojr/1srj3i7XXXZ2Xo1HYvTiL29G0=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=n0zd+O3r55LqYjDoskRSxdlBOfgpEMMLSFXs50r67Avssxq29H+hFukXjFu+Dv5Nr 6r7vM2nXnJdReZ5QepXWWBj+CAr1NicyeeXB59bZ7JNVeE5/aZkRS2nCEuiTFRjxEc 9sDXsEuJMrZuf6EhznaWQw4wy0huoPFDwODw9FAY= Received: from mail.rzn.dlink.ru (mail.rzn.dlink.ru [178.170.168.13]) by fd.dlink.ru (Postfix) with ESMTP id A454B1B209D6; Wed, 27 Nov 2019 10:47:26 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 fd.dlink.ru A454B1B209D6 Received: from mail.rzn.dlink.ru (localhost [127.0.0.1]) by mail.rzn.dlink.ru (Postfix) with ESMTP id 4F7721B2023D; Wed, 27 Nov 2019 10:47:26 +0300 (MSK) Received: from mail.rzn.dlink.ru (localhost [127.0.0.1]) by mail.rzn.dlink.ru (Postfix) with ESMTPA; Wed, 27 Nov 2019 10:47:26 +0300 (MSK) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Date: Wed, 27 Nov 2019 10:47:26 +0300 From: Alexander Lobakin To: David Miller Cc: pabeni@redhat.com, johannes@sipsolutions.net, ecree@solarflare.com, nicholas.johnson-opensource@outlook.com.au, jiri@mellanox.com, edumazet@google.com, idosch@mellanox.com, petrm@mellanox.com, sd@queasysnail.net, f.fainelli@gmail.com, jaswinder.singh@linaro.org, ilias.apalodimas@linaro.org, linux-kernel@vger.kernel.org, emmanuel.grumbach@intel.com, luciano.coelho@intel.com, linuxwifi@intel.com, kvalo@codeaurora.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org Subject: Re: [PATCH v2 net-next] net: core: use listified Rx for GRO_NORMAL in napi_gro_receive() In-Reply-To: <20191126.155746.627765091618337419.davem@davemloft.net> References: <414288fcac2ba4fcee48a63bdbf28f7b9a5037c6.camel@sipsolutions.net> <20191126.155746.627765091618337419.davem@davemloft.net> User-Agent: Roundcube Webmail/1.4.0 Message-ID: <4cb1abfb7cbd137151f024405f7b0678@dlink.ru> X-Sender: alobakin@dlink.ru Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org David Miller wrote 27.11.2019 02:57: > From: Alexander Lobakin > Date: Mon, 25 Nov 2019 15:02:24 +0300 > >> Paolo Abeni wrote 25.11.2019 14:42: >>> For -net, I *think* something as dumb and hacky as the following >>> could >>> possibly work: >>> ---- >>> diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c >>> b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c >>> index 4bba6b8a863c..df82fad96cbb 100644 >>> --- a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c >>> +++ b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c >>> @@ -1527,7 +1527,7 @@ static void iwl_pcie_rx_handle(struct iwl_trans >>> *trans, int queue) >>> iwl_pcie_rxq_alloc_rbs(trans, GFP_ATOMIC, rxq); >>> if (rxq->napi.poll) >>> - napi_gro_flush(&rxq->napi, false); >>> + napi_complete_done(&rxq->napi, 0); >>> iwl_pcie_rxq_restock(trans, rxq); >>> } >>> --- >> >> napi_complete_done(napi, 0) has an equivalent static inline >> napi_complete(napi). I'm not sure it will work without any issues >> as iwlwifi doesn't _really_ turn NAPI into scheduling state. >> >> I'm not very familiar with iwlwifi, but as a work around manual >> napi_gro_flush() you can also manually flush napi->rx_list to >> prevent packets from stalling: >> >> diff -Naur a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c >> b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c >> --- a/drivers/net/wireless/intel/iwlwifi/pcie/rx.c 2019-11-25 >> --- 14:55:03.610355230 +0300 >> +++ b/drivers/net/wireless/intel/iwlwifi/pcie/rx.c 2019-11-25 >> 14:57:29.399556868 +0300 > ... > > Thanks to everyone for looking into this. > > Can I get some kind of fix in the next 24 hours? I want to send a > quick > follow-on pull request to Linus to deal with all of the fallout, and in > particular fix this regression. If Intel guys and others will agree, I'll send a patch which will add manual napi->rx_list flushing in iwlwifi driver in about ~2-3 hours. Anyway, this driver should get a proper NAPI in future releases to prevent problems like this one. > Thanks! Regards, ᚷ ᛖ ᚢ ᚦ ᚠ ᚱ