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,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 EF540C432C0 for ; Wed, 27 Nov 2019 10:12:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C1DD020722 for ; Wed, 27 Nov 2019 10:12:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=dlink.ru header.i=@dlink.ru header.b="QB9oNjfy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726933AbfK0KMw (ORCPT ); Wed, 27 Nov 2019 05:12:52 -0500 Received: from fd.dlink.ru ([178.170.168.18]:50230 "EHLO fd.dlink.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726194AbfK0KMw (ORCPT ); Wed, 27 Nov 2019 05:12:52 -0500 Received: by fd.dlink.ru (Postfix, from userid 5000) id 1E90F1B20138; Wed, 27 Nov 2019 13:12:49 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 fd.dlink.ru 1E90F1B20138 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dlink.ru; s=mail; t=1574849569; bh=lE5ZjRG9JmDTb+3gD8rd1avjZlPCQcl4MjmyxAXK12o=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=QB9oNjfyB6ZyhhLnx62KtkficOqyPSHP8yIDJwE2LObLbVmXPhskf5KpTlacf5Bs+ 9v2Tfn0DQvgfZcyr9ZiUUMgsvOlW4VISs7qr+g3lAIfeMasSZb/MzGIaBrW/gPdddk E5HAgR6xE5vgKT+xP05CAUgFN0NmchUGIL6Z6KtQ= Received: from mail.rzn.dlink.ru (mail.rzn.dlink.ru [178.170.168.13]) by fd.dlink.ru (Postfix) with ESMTP id 98EEC1B20153; Wed, 27 Nov 2019 13:12:34 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 fd.dlink.ru 98EEC1B20153 Received: from mail.rzn.dlink.ru (localhost [127.0.0.1]) by mail.rzn.dlink.ru (Postfix) with ESMTP id 420D21B22678; Wed, 27 Nov 2019 13:12:34 +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 13:12:34 +0300 (MSK) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Date: Wed, 27 Nov 2019 13:12:34 +0300 From: Alexander Lobakin To: Luciano Coelho Cc: "David S. Miller" , Edward Cree , Jiri Pirko , Eric Dumazet , Ido Schimmel , Paolo Abeni , Petr Machata , Sabrina Dubroca , Florian Fainelli , Jassi Brar , Manish Chopra , GR-Linux-NIC-Dev@marvell.com, Johannes Berg , Emmanuel Grumbach , Intel Linux Wireless , Kalle Valo , Nicholas Johnson , "Kenneth R. Crudup" , netdev@vger.kernel.org, linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net] net: wireless: intel: iwlwifi: fix GRO_NORMAL packet stalling In-Reply-To: <7a9332bf645fbb8c9fff634a3640c092fb9b4b79.camel@intel.com> References: <20191127094123.18161-1-alobakin@dlink.ru> <7a9332bf645fbb8c9fff634a3640c092fb9b4b79.camel@intel.com> User-Agent: Roundcube Webmail/1.4.0 Message-ID: X-Sender: alobakin@dlink.ru Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Luciano Coelho wrote 27.11.2019 12:58: > On Wed, 2019-11-27 at 12:41 +0300, Alexander Lobakin wrote: >> Commit 6570bc79c0df ("net: core: use listified Rx for GRO_NORMAL in >> napi_gro_receive()") has applied batched GRO_NORMAL packets processing >> to all napi_gro_receive() users, including mac80211-based drivers. >> >> However, this change has led to a regression in iwlwifi driver [1][2] >> as >> it is required for NAPI users to call napi_complete_done() or >> napi_complete() and the end of every polling iteration, whilst iwlwifi >> doesn't use NAPI scheduling at all and just calls napi_gro_flush(). >> In that particular case, packets which have not been already flushed >> from napi->rx_list stall in it until at least next Rx cycle. >> >> Fix this by adding a manual flushing of the list to iwlwifi driver >> right >> before napi_gro_flush() call to mimic napi_complete() logics. >> >> I prefer to open-code gro_normal_list() rather than exporting it for 2 >> reasons: >> * to prevent from using it and napi_gro_flush() in any new drivers, >> as it is the *really* bad way to use NAPI that should be avoided; >> * to keep gro_normal_list() static and don't lose any CC >> optimizations. >> >> I also don't add the "Fixes:" tag as the mentioned commit was only a >> trigger that only exposed an improper usage of NAPI in this particular >> driver. >> >> [1] >> https://lore.kernel.org/netdev/PSXP216MB04388962C411CD0B17A86F47804A0@PSXP216MB0438.KORP216.PROD.OUTLOOK.COM >> [2] https://bugzilla.kernel.org/show_bug.cgi?id=205647 >> >> Signed-off-by: Alexander Lobakin >> --- > > We don't usually use "net: wireless: intel:" in the commit message, we > would use "iwlwifi: pcie:", but I don't care much. > > Otherwise: > > Acked-by: Luca Coelho Thank you! > Thanks a lot for the fix! > > Dave, I'm assuming you'll take this directly into your tree, right? Also please let me know if I should send v2 with Ack and fixed commit subject! > -- > Cheers, > Luca. Regards, ᚷ ᛖ ᚢ ᚦ ᚠ ᚱ