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=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 019C1C43603 for ; Wed, 4 Dec 2019 11:38:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C55D8207DD for ; Wed, 4 Dec 2019 11:38:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="BxxIs+FA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727701AbfLDLim (ORCPT ); Wed, 4 Dec 2019 06:38:42 -0500 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:31420 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727268AbfLDLim (ORCPT ); Wed, 4 Dec 2019 06:38:42 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1575459521; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=76Eat5h9hj7twLSmI7D+BtbdtTI6olcMmFKdFbpmaf4=; b=BxxIs+FACYidgAczg2HyixwXM0rYufonkFmriyEvBRYNilDoCXYwhPIeDSip+LU5013Jpq aXXx86nHxjI9HmZ41664dKv/Z19C+yXq9zn5Rxi7CWNmSzoy0+AlPkclRP0LTUlhX57mo+ X5/w/0SBKVeKudUSEUvDkL9PSq2fvxc= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-142-6gLLU8wFOaOcBmt7TsbTwQ-1; Wed, 04 Dec 2019 06:38:36 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AA48B91253; Wed, 4 Dec 2019 11:38:35 +0000 (UTC) Received: from carbon (ovpn-200-56.brq.redhat.com [10.40.200.56]) by smtp.corp.redhat.com (Postfix) with ESMTP id B35DE1D1; Wed, 4 Dec 2019 11:38:30 +0000 (UTC) Date: Wed, 4 Dec 2019 12:38:29 +0100 From: Jesper Dangaard Brouer To: Grygorii Strashko Cc: Jonathan Lemon , , , , Ilias Apalodimas , brouer@redhat.com Subject: Re: [net PATCH] xdp: obtain the mem_id mutex before trying to remove an entry. Message-ID: <20191204123829.2af45813@carbon> In-Reply-To: <64b28372-e203-92db-bc67-1c308334042f@ti.com> References: <20191203220114.1524992-1-jonathan.lemon@gmail.com> <20191204093240.581543f3@carbon> <64b28372-e203-92db-bc67-1c308334042f@ti.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-MC-Unique: 6gLLU8wFOaOcBmt7TsbTwQ-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, 4 Dec 2019 12:07:22 +0200 Grygorii Strashko wrote: > On 04/12/2019 10:32, Jesper Dangaard Brouer wrote: > > On Tue, 3 Dec 2019 14:01:14 -0800 > > Jonathan Lemon wrote: > > > >> A lockdep splat was observed when trying to remove an xdp memory > >> model from the table since the mutex was obtained when trying to > >> remove the entry, but not before the table walk started: > >> > >> Fix the splat by obtaining the lock before starting the table walk. > >> > >> Fixes: c3f812cea0d7 ("page_pool: do not release pool until inflight == 0.") > >> Reported-by: Grygorii Strashko > >> Signed-off-by: Jonathan Lemon > > > > Have you tested if this patch fix the problem reported by Grygorii? > > > > Link: https://lore.kernel.org/netdev/c2de8927-7bca-612f-cdfd-e9112fee412a@ti.com > > > > Grygorii can you test this? > > Thanks. > I do not see this trace any more and networking is working after if down/up > > Tested-by: Grygorii Strashko > Well if it fixes you issue, then I guess its okay. Acked-by: Jesper Dangaard Brouer I just though it was related to the rcu_read_lock() around the page_pool_destroy() call. Guess, I was wrong. -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer