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=-11.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 65B25C433C1 for ; Mon, 22 Mar 2021 09:26:17 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D7DFA61973 for ; Mon, 22 Mar 2021 09:26:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D7DFA61973 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id BAE036B0096; Mon, 22 Mar 2021 05:07:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B83D96B0098; Mon, 22 Mar 2021 05:07:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A4B256B0099; Mon, 22 Mar 2021 05:07:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0102.hostedemail.com [216.40.44.102]) by kanga.kvack.org (Postfix) with ESMTP id 893136B0096 for ; Mon, 22 Mar 2021 05:07:25 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id EB29F8249980 for ; Mon, 22 Mar 2021 09:26:15 +0000 (UTC) X-FDA: 77946979110.22.364F00C Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf25.hostedemail.com (Postfix) with ESMTP id 79C6F6000109 for ; Mon, 22 Mar 2021 09:26:15 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id BD61A60233; Mon, 22 Mar 2021 09:26:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616405174; bh=E2bivXSoDRMs7r3zMZVSaMr3GBidjFUkYCkNU0ecnDs=; h=In-Reply-To:References:Subject:Cc:From:To:Date:From; b=gnV0wWkuwrUy4FWlG4rSqyC7z+OLCTzeqSL7gEv2kIA/p8ycJHV9+S0Dsklnv4QbU +SmVeBy8+KaUSfWOnGa+dQXgXZrNm4cyYNmOSRXisLoT+PLM4Zyt8WzubUgBldxEe/ M/mQdFQh8sPBOkPUbBz+Bkz0+xCC8aoq9Wx73xhNlQrt4JfyAZIXhArxZLTS/RZ5uj vjZ3quCo/y393PCXarHrJWBKOQFIJBNpBEZFQfpT2cVBbgFhDc6WaFNz6DyfDAs/T8 veh/Rx3ad7qNigCXWfVj73lRNZSbXbKv+SRlDG2QCpMWfXn9rhiUjQgw8w1vxXUhUe bV8Xid8fmCmQQ== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable In-Reply-To: <20210322090536.GK1719932@casper.infradead.org> References: <20210322083553.GI32426@xsang-OptiPlex-9020> <161640335063.3537.6668586361113979688@kwain.local> <20210322090536.GK1719932@casper.infradead.org> Subject: Re: [net] 5478fcd0f4: BUG:sleeping_function_called_from_invalid_context_at_include/linux/sched/mm.h Cc: kernel test robot , "David S. Miller" , Alexander Duyck , LKML , Linux Memory Management List , lkp@lists.01.org, lkp@intel.com, ltp@lists.linux.it From: Antoine Tenart To: Matthew Wilcox Message-ID: <161640517096.3021.7957377947074787708@kwain.local> Date: Mon, 22 Mar 2021 10:26:11 +0100 X-Stat-Signature: 1re5jgotyeje7a36uz1whhdre1xt7mb3 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 79C6F6000109 Received-SPF: none (kernel.org>: No applicable sender policy available) receiver=imf25; identity=mailfrom; envelope-from=""; helo=mail.kernel.org; client-ip=198.145.29.99 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1616405175-340022 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Quoting Matthew Wilcox (2021-03-22 10:05:36) > On Mon, Mar 22, 2021 at 09:55:50AM +0100, Antoine Tenart wrote: > > I only had a quick look at this, but I think the issue should be fixed > > with: > >=20 > > diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c > > index e16d54aabd4c..3ae3c20eb64c 100644 > > --- a/net/core/net-sysfs.c > > +++ b/net/core/net-sysfs.c > > @@ -1378,7 +1378,7 @@ static ssize_t xps_queue_show(struct net_device *= dev, unsigned int index, > > nr_ids =3D dev_maps ? dev_maps->nr_ids : > > (type =3D=3D XPS_CPUS ? nr_cpu_ids : dev->num_rx_queue= s); > > =20 > > - mask =3D bitmap_zalloc(nr_ids, GFP_KERNEL); > > + mask =3D bitmap_zalloc(nr_ids, GFP_ATOMIC); > > if (!mask) { > > rcu_read_unlock(); > > return -ENOMEM; >=20 > sysfs isn't a good reason to use GFP_ATOMIC. >=20 > try something like this: >=20 > - mask =3D bitmap_zalloc(nr_ids, GFP_KERNEL); > + mask =3D bitmap_zalloc(nr_ids, GFP_NOWAIT); > if (!mask) { > + int new_nr_ids; > + > rcu_read_unlock(); > - return -ENOMEM; > + mask =3D bitmap_zalloc(nr_ids, GFP_KERNEL); > + if (!mask) > + return -ENOMEM; > + rcu_read_lock(); > + dev_maps =3D rcu_dereference(dev->xps_maps[type]); > + /* if nr_ids shrank while we slept, do not overrun array. > + * if it increased, we just won't show the new ones > + */ > + new_nr_ids =3D dev_maps ? dev_maps->nr_ids : > + (type =3D=3D XPS_CPUS ? nr_cpu_ids : dev->num_rx_= queues); > + if (new_nr_ids < nr_ids) > + nr_ids =3D new_nr_ids; Thanks for the suggestion, I'll look into that. We could also just return -ENOMEM if the first allocation fails, retrying adds a lot of complexity. Antoine