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=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 37C82C3F2C6 for ; Tue, 3 Mar 2020 17:47:26 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F22BD21739 for ; Tue, 3 Mar 2020 17:47:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="c/OQQJrd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F22BD21739 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 89F126B0005; Tue, 3 Mar 2020 12:47:25 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 850806B0006; Tue, 3 Mar 2020 12:47:25 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6EFEA6B0007; Tue, 3 Mar 2020 12:47:25 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0132.hostedemail.com [216.40.44.132]) by kanga.kvack.org (Postfix) with ESMTP id 52FFA6B0005 for ; Tue, 3 Mar 2020 12:47:25 -0500 (EST) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id C6161181AC9CB for ; Tue, 3 Mar 2020 17:47:24 +0000 (UTC) X-FDA: 76554782808.23.lock81_5dcc3d85a5e2f X-HE-Tag: lock81_5dcc3d85a5e2f X-Filterd-Recvd-Size: 4714 Received: from mail-ed1-f67.google.com (mail-ed1-f67.google.com [209.85.208.67]) by imf30.hostedemail.com (Postfix) with ESMTP for ; Tue, 3 Mar 2020 17:47:24 +0000 (UTC) Received: by mail-ed1-f67.google.com with SMTP id h62so5438595edd.12 for ; Tue, 03 Mar 2020 09:47:24 -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=bjmE4FqswyFqab5pR4FSoptSLw3dwl2KhPYJsiGVaKQ=; b=c/OQQJrdJ/J0ZzFuZ+Rchvnm7nYSG5o01Li0NhxPrrTXknrezvFude//DvuOFcIC6q ymU1VEblUy12me7yrh5TbwU3doacnNekEcuS9A5W8CyJRykGXSiMweaE882/AJeD8qCw othWBfE7ZAuMZ8k3S1dNlKa7vpmr40FC4RDBVy3AAfJ0g4FywGG57oCqpYLjetHU1XHq RaDQ5TrV7A+Y4wPwdFXCQoAJocCDNx5xVTIiuSf+RgTQLCZZGXH+8ScZszW9mb42/OfZ 0O1o3e+g6NDeF5DO+ykEyBQUa8BrZWUZyGZL6IcwVS9Kfr+R/tYTmKaXeahu3VowiTdk n/2w== 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=bjmE4FqswyFqab5pR4FSoptSLw3dwl2KhPYJsiGVaKQ=; b=NwG6WcwjAU7xDRctie4JnVak/mW69guRP8BMJ7j48YOPmrKsS50pEjZKdfsuZTJdGk 14qGgNy4QPrSS16SKkfad0BrPsI9/KFXhDyPXiNFVRVqLmHJAkkNqDNg9hEciuEvsguR jIytSedQDA5b5DrX6wGT3NPCzwmldrKofPUfItvJS0j9jawTu8SwNMAEEgvh/8RRDT5J rmjUP0JZzJYKXu/IVMdhuP50jsZ2xj2auBqEssJfcmw+9Xo5K3NM8PZ+YCgRnGeohRPP d4nxJLyQKWr2Q4VAqgJ18iFvKJW/E6M2FSmCgmeNPbIJiHgjC/g9LEWrA8Ak/IUniOwu p3hQ== X-Gm-Message-State: ANhLgQ3sRlJk6p5DIPfhMfW0/dMaIhtt+ooQGjWl65ebr/V+DuhLpa3t 3IUL/IpFnxr7MHEWBSQ5KpynCPeSv4Ppl8LfZY4= X-Google-Smtp-Source: ADFU+vs77kLnVZT6Wccf2Nd7FJV8u1j4kr8EEbqWVi4IwHVCTPiiqf1UrJ9ia6hHoxkJva7MzfqDBXcUnTVK1wqBgoY= X-Received: by 2002:a17:906:ad96:: with SMTP id la22mr4380586ejb.310.1583257643334; Tue, 03 Mar 2020 09:47:23 -0800 (PST) MIME-Version: 1.0 References: <0a37bb7d-18a7-c43c-52a5-f13a34decf69@i-love.sakura.ne.jp> In-Reply-To: <0a37bb7d-18a7-c43c-52a5-f13a34decf69@i-love.sakura.ne.jp> From: Yang Shi Date: Tue, 3 Mar 2020 09:47:07 -0800 Message-ID: Subject: Re: fs/buffer.c: WARNING: alloc_page_buffers while mke2fs To: Tetsuo Handa Cc: Naresh Kamboju , linux-mm , Andrew Morton , Mel Gorman , Michal Hocko , Shakeel Butt , schatzberg.dan@gmail.com Content-Type: text/plain; charset="UTF-8" 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: On Tue, Mar 3, 2020 at 2:53 AM Tetsuo Handa wrote: > > Hello, Naresh. > > > [ 98.003346] WARNING: CPU: 2 PID: 340 at > > include/linux/sched/mm.h:323 alloc_page_buffers+0x210/0x288 > > This is > > /** > * memalloc_use_memcg - Starts the remote memcg charging scope. > * @memcg: memcg to charge. > * > * This function marks the beginning of the remote memcg charging scope. All the > * __GFP_ACCOUNT allocations till the end of the scope will be charged to the > * given memcg. > * > * NOTE: This function is not nesting safe. > */ > static inline void memalloc_use_memcg(struct mem_cgroup *memcg) > { > WARN_ON_ONCE(current->active_memcg); > current->active_memcg = memcg; > } > > which is about memcg. Redirecting to linux-mm. Isn't this triggered by ("loop: use worker per cgroup instead of kworker") in linux-next, which converted loop driver to use worker per cgroup, so it may have multiple workers work at the mean time? So they may share the same "current", then it may cause kind of nested call to memalloc_use_memcg(). Could you please try the below debug patch? This is not the proper fix, but it may help us narrow down the problem. diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h index c49257a..1cc1cdc 100644 --- a/include/linux/sched/mm.h +++ b/include/linux/sched/mm.h @@ -320,6 +320,10 @@ static inline void memalloc_nocma_restore(unsigned int flags) */ static inline void memalloc_use_memcg(struct mem_cgroup *memcg) { + if ((current->flags & PF_KTHREAD) && + current->active_memcg) + return; + WARN_ON_ONCE(current->active_memcg); current->active_memcg = memcg; } > > Please include exact backtrace extracted from scripts/faddr2line . > >