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=-3.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 A43B4C43603 for ; Wed, 4 Dec 2019 17:30:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 77A0E2077B for ; Wed, 4 Dec 2019 17:30:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="A+DNL8pG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728171AbfLDRam (ORCPT ); Wed, 4 Dec 2019 12:30:42 -0500 Received: from mail-pl1-f193.google.com ([209.85.214.193]:35557 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726934AbfLDRam (ORCPT ); Wed, 4 Dec 2019 12:30:42 -0500 Received: by mail-pl1-f193.google.com with SMTP id s10so19737plp.2 for ; Wed, 04 Dec 2019 09:30:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version; bh=IUMhmPzNJS6OUWDxn0WL/R+Ty9K7orUyiXqUYVAEZz0=; b=A+DNL8pGNpe6Q8EraPfmoTiK8b4OXPkesBs0KZ8LS3LmmLd8CvyU0ZOGOqth2QmQHd w5vItFR6Uvv6EHbRiSpbjlPxfqPMU7bW4dZo/NqGhKhaTScNUp79XsaFkGiCq6WsvLTZ JqZjDJyrq9YR4gn3r3IFzdUu1dsC6d3PdIT+lBNwo8fwCzddrsqlTlYslpvDrK9dUrlR WhsExDAVRqPFEQWOpgJZVkN2EnjWa+/dhlg4c1vlxJx2nsVhzRQwh1msljiGYFtE5b4V OdP6ZvoJkUqD9UdSVBdtoC1fcQ3KMGXlKfv02DWZrHFDEodyofdlCsLpMlZ+JHGYgKdN TxpA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version; bh=IUMhmPzNJS6OUWDxn0WL/R+Ty9K7orUyiXqUYVAEZz0=; b=d4DFuVAlYoskzF8V4I2w63HQ/ppoMBDWYG4ZJIo9geHx2c8Os1KitaJLtUg6o/wRRp ReddxHwA9tm2pOU+t2nyBsZxz948vwAooyGlpz5Lgx7WOay0q1qhxhPDFmbdzXutDATN qfZmOcRZJTwA5z37GgEWsT0en0j//gl4l+XagXnsI2K/IKYc599q105hjyqOHky5BfLD 3P3qx60MSFGwFkGRO1xiH/zvut2/5YHEoz8+QMel2ZLl4owdfmsiUu3Pjc7VUTqqdwft J2e08VY12/KEngeT98AsEeVymmYZxLw3VF/4LAoO6CANP49EIPdcU4hjtuUMIeNZrh6R 2SRA== X-Gm-Message-State: APjAAAX0NhupTyq29KGSLJyStRMfvNpgh4nLm5aL+qOxCqQClbLTsBjk Ys6FDLW7zFEWmXbgBuN+05E= X-Google-Smtp-Source: APXvYqyBCZHQwvdgZxHD3Nvspj8hYFZrEUwtb8dab3PMcdl/J38jZv4l48U8IpT5SbwUAsGTMlZLNw== X-Received: by 2002:a17:902:904c:: with SMTP id w12mr4624215plz.144.1575480641698; Wed, 04 Dec 2019 09:30:41 -0800 (PST) Received: from [172.20.160.202] ([2620:10d:c090:180::5fe1]) by smtp.gmail.com with ESMTPSA id p5sm8619748pga.69.2019.12.04.09.30.40 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 04 Dec 2019 09:30:40 -0800 (PST) From: "Jonathan Lemon" To: "Jesper Dangaard Brouer" Cc: "Grygorii Strashko" , netdev@vger.kernel.org, davem@davemloft.net, kernel-team@fb.com, "Ilias Apalodimas" Subject: Re: [net PATCH] xdp: obtain the mem_id mutex before trying to remove an entry. Date: Wed, 04 Dec 2019 09:30:18 -0800 X-Mailer: MailMate (1.13r5655) Message-ID: <49A0ABFF-32CD-4F21-B091-0997DC805B7B@gmail.com> In-Reply-To: <20191204123829.2af45813@carbon> References: <20191203220114.1524992-1-jonathan.lemon@gmail.com> <20191204093240.581543f3@carbon> <64b28372-e203-92db-bc67-1c308334042f@ti.com> <20191204123829.2af45813@carbon> MIME-Version: 1.0 Content-Type: text/plain; format=flowed Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 4 Dec 2019, at 3:38, Jesper Dangaard Brouer wrote: > 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? Yes, I reproduced the problem locally, and confirmed that the patch resolves the issue. -- Jonathan >>> >>> 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