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=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 D289AC388F9 for ; Sun, 8 Nov 2020 17:49:41 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3132C22203 for ; Sun, 8 Nov 2020 17:49:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="c2wPjCUc" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3132C22203 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5441E6B0036; Sun, 8 Nov 2020 12:49:40 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 4F48D6B005D; Sun, 8 Nov 2020 12:49:40 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 409CA6B0068; Sun, 8 Nov 2020 12:49:40 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0218.hostedemail.com [216.40.44.218]) by kanga.kvack.org (Postfix) with ESMTP id 105876B0036 for ; Sun, 8 Nov 2020 12:49:40 -0500 (EST) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id AE03E8249980 for ; Sun, 8 Nov 2020 17:49:39 +0000 (UTC) X-FDA: 77461988478.12.pot76_4d04116272e5 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin12.hostedemail.com (Postfix) with ESMTP id 8EBF3180559F1 for ; Sun, 8 Nov 2020 17:49:39 +0000 (UTC) X-HE-Tag: pot76_4d04116272e5 X-Filterd-Recvd-Size: 3616 Received: from mail-ed1-f51.google.com (mail-ed1-f51.google.com [209.85.208.51]) by imf05.hostedemail.com (Postfix) with ESMTP for ; Sun, 8 Nov 2020 17:49:39 +0000 (UTC) Received: by mail-ed1-f51.google.com with SMTP id a15so6358273edy.1 for ; Sun, 08 Nov 2020 09:49:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=npDhHdyb+e38uG7TqZOalosD4U2mEyKASn9MbxIr/Sc=; b=c2wPjCUcGg5IMVZxaUin/wHr+sLB1Lj1D8YTEsDUrcaBRnXFCuWuFsFfdVj4orKL+4 R3kYCguC51mnE6rymNivm/5HCfCHBu98X41Jndhacgqnk4DAbBLiBpiQiFFXGVFcJe4T h2Ytfk7U7KYqJFod6WtR+6Kb2Unq546H5aCcpLbBFy59Y6W9Ph76IzWY1/VZ7fFHoSu2 3sf3mfYFHjWw3wTpYVfGMU4zcrQN3U/3mquoSNS1japt3sVx5jjjpUhf6nYcIYhX5jIS EZlFWXyn1spomnZzOGPyhBdvdV2vmborlAsXqWoe8RPoX1df8nyJw3Of/tBfW0fXkzoH DupA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=npDhHdyb+e38uG7TqZOalosD4U2mEyKASn9MbxIr/Sc=; b=sJttH3Qm0FlQT6uxL63bal8z2azRhVeVCwM+4W9YsMsjksdNNr81GboJdGb1Jxfwgo oaNsOCiMbgnplt7ff2ay+7N4FXDhbYPdpasVYP2bLvUMUcZ+pZbqvdjhO4cPaarRHMu9 yF6dSIsR61DAkdratuoltSZYKQoeqqoiQ5cs0k/ah0hmKdEUDVS+LQcipGwuAbKI83CG pfuTJytPmPfRTvamJ/29fOWx9YxkewGdWlnZxh8dEUtKzud/vSlUROxbbAqO0vCcgm6L 4ts+pdCvCzG5ZIe/JH3v6awjLLCnpJBZNONseS0Uqp1UaQS5SCRGhNvMe1O0u0ACcr/H O8lA== X-Gm-Message-State: AOAM5322YzL2EcVs1nbvAgEnPzBV/TFQij+e2ASA43pJWLWRK6T1kDN+ S0JjDFxL8q7Jc5MLWp49Y1Lv0LBmOZUrxJIR7bA= X-Google-Smtp-Source: ABdhPJy61wsNLWhEhWjFiBfjcsCAM0LENNYU8L+HdCfWnVkAgHKKOQWXAV+xpl8dvQoBrPdfGaNNyoydwBz5twHAAXk= X-Received: by 2002:a50:eb96:: with SMTP id y22mr11813487edr.116.1604857777967; Sun, 08 Nov 2020 09:49:37 -0800 (PST) MIME-Version: 1.0 References: <20201106211300.23179b5680fd8c83a07a095b@linux-foundation.org> In-Reply-To: <20201106211300.23179b5680fd8c83a07a095b@linux-foundation.org> From: Lorenzo Stoakes Date: Sun, 8 Nov 2020 17:49:27 +0000 Message-ID: Subject: Re: [Bug 210075] New: [Thu Nov 5 13:14:27 2020] WARNING: CPU: 4 PID: 133 at mm/page_counter.c:57 page_counter_uncharge+0x34/0x40 To: Andrew Morton Cc: linux-mm , bugzilla-daemon@bugzilla.kernel.org, vladi@aresgate.net, Johannes Weiner , Michal Hocko Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.016402, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Looking to jump back into some kernel hacking again so thought I'd take a quick rusty look. Pattern matching a bit but I wonder whether f2fe7b09 (mm: memcg/slab: charge individual slab objects instead of pages) may have had a role in this bug as it adds an obj_cgroup_uncharge() invocation to memcg_slab_free_hook() invoked from kmem_cache_free(). sk_prot_free() also invokes mem_cgroup_sk_free() before kmem_cache_free() so perhaps an uncharge is getting doubled up here? I traced through mem_cgroup_sk_free() (which invokes css_put()) but couldn't see where it would result in an additional uncharge so I may be barking up the wrong tree here. I'd be more than happy to have a deeper look at this if vladi has some code that repro's this + a .config, if that'd be helpful. Best, Lorenzo