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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 831ACC433B4 for ; Mon, 26 Apr 2021 06:47:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 51C3561131 for ; Mon, 26 Apr 2021 06:47:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232008AbhDZGsX (ORCPT ); Mon, 26 Apr 2021 02:48:23 -0400 Received: from vulcan.natalenko.name ([104.207.131.136]:40852 "EHLO vulcan.natalenko.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231616AbhDZGsW (ORCPT ); Mon, 26 Apr 2021 02:48:22 -0400 Received: from localhost (kaktus.kanapka.ml [151.237.229.131]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by vulcan.natalenko.name (Postfix) with ESMTPSA id B09E1A4F81D; Mon, 26 Apr 2021 08:47:37 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=natalenko.name; s=dkim-20170712; t=1619419657; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=hFtP1eOQddasIQX+cRuKOVejzwpAMEMFVa7yR+iwH4I=; b=L3ZsAqfUjUWgneNywT2x9J81/ncsgSJzdZrKsmkpSJOI2ZW8NXFvavseYFTF4bRJsIcrCY hk1gIisOhNWdd4LKvWzgOdOLAQsq9UPvVlWR4VRjButDwaCZ5K1lp1HYur1S0KyHX5h3xK wcwlTBb3d9XfYW1ElJgpdoNQLXyKLQg= Date: Mon, 26 Apr 2021 08:47:36 +0200 From: Oleksandr Natalenko To: Jakub Kicinski Cc: Alexander Duyck , linux-kernel@vger.kernel.org, Jesse Brandeburg , Tony Nguyen , "David S. Miller" , intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org Subject: Re: [igb] netconsole triggers warning in netpoll_poll_dev Message-ID: <20210426064736.7efynita4brzos4u@spock.localdomain> References: <20210406123619.rhvtr73xwwlbu2ll@spock.localdomain> <20210406114734.0e00cb2f@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <20210407060053.wyo75mqwcva6w6ci@spock.localdomain> <20210407083748.56b9c261@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <20210407110722.1eb4ebf2@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <20210423081944.kvvm4v7jcdyj74l3@spock.localdomain> <20210423155836.25ef1e77@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210423155836.25ef1e77@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello. On Fri, Apr 23, 2021 at 03:58:36PM -0700, Jakub Kicinski wrote: > On Fri, 23 Apr 2021 10:19:44 +0200 Oleksandr Natalenko wrote: > > On Wed, Apr 07, 2021 at 04:06:29PM -0700, Alexander Duyck wrote: > > > On Wed, Apr 7, 2021 at 11:07 AM Jakub Kicinski wrote: > > > > Sure, that's simplest. I wasn't sure something is supposed to prevent > > > > this condition or if it's okay to cover it up. > > > > > > I'm pretty sure it is okay to cover it up. In this case the "budget - > > > 1" is supposed to be the upper limit on what can be reported. I think > > > it was assuming an unsigned value anyway. > > > > > > Another alternative would be to default clean_complete to !!budget. > > > Then if budget is 0 clean_complete would always return false. > > > > So, among all the variants, which one to try? Or there was a separate > > patch sent to address this? > > Alex's suggestion is probably best. > > I'm not aware of the fix being posted. Perhaps you could take over and > post the patch if Intel doesn't chime in? So, IIUC, Alex suggests this: ``` diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index a45cd2b416c8..7503d5bf168a 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -7981,7 +7981,7 @@ static int igb_poll(struct napi_struct *napi, int budget) struct igb_q_vector, napi); bool clean_complete = true; - int work_done = 0; + unsigned int work_done = 0; #ifdef CONFIG_IGB_DCA if (q_vector->adapter->flags & IGB_FLAG_DCA_ENABLED) @@ -8008,7 +8008,7 @@ static int igb_poll(struct napi_struct *napi, int budget) if (likely(napi_complete_done(napi, work_done))) igb_ring_irq_enable(q_vector); - return min(work_done, budget - 1); + return min_t(unsigned int, work_done, budget - 1); } /** ``` Am I right? Thanks. -- Oleksandr Natalenko (post-factum)