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=-11.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 AD6E7C3F2D1 for ; Tue, 3 Mar 2020 18:15:03 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6E09520656 for ; Tue, 3 Mar 2020 18:15:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="lu75l+jW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6E09520656 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 09AEB6B0005; Tue, 3 Mar 2020 13:15:03 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 04BE96B0006; Tue, 3 Mar 2020 13:15:02 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EA3A66B0007; Tue, 3 Mar 2020 13:15:02 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0153.hostedemail.com [216.40.44.153]) by kanga.kvack.org (Postfix) with ESMTP id CF3246B0005 for ; Tue, 3 Mar 2020 13:15:02 -0500 (EST) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 5DF972C06 for ; Tue, 3 Mar 2020 18:15:02 +0000 (UTC) X-FDA: 76554852444.10.use58_2befedb0fe309 X-HE-Tag: use58_2befedb0fe309 X-Filterd-Recvd-Size: 5018 Received: from mail-oi1-f194.google.com (mail-oi1-f194.google.com [209.85.167.194]) by imf25.hostedemail.com (Postfix) with ESMTP for ; Tue, 3 Mar 2020 18:15:01 +0000 (UTC) Received: by mail-oi1-f194.google.com with SMTP id x75so275640oix.5 for ; Tue, 03 Mar 2020 10:15:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=EdTsnDU68CSafsMDnK1Ks19zYSzqARvJLxE0LQ6P+Lg=; b=lu75l+jWTR1Sb6xWSfoFF5QAcuJcmlDufN+zwiKHcWEJx52zGwxMV+0ahtE32aN9I3 xFY7UHL8ARuR0EQ1eMNpRZJCndUrxsLFfsA/hiBwJAvm6FxP+b+zIfnTrtisKw+Nby1O yotgpO4I1hHuVTRUtS5E9dNVeD1FTfqR4ycpM91UXye2mq+/mSTqGTmjfPgRewIyhr8X EKj4YhxZ2ymAl1E2YRabXjFjdStLMKcBU9aNo1fVKbwmEeHb7CeRFzM3LZJWx12EWh48 1yDezmJhF+hTP3UD9XrEiRGHtHsz7q2q04rWISGhNCjX1O8fHm8bdVN+1vm3N2SyYLK9 tl6Q== 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=EdTsnDU68CSafsMDnK1Ks19zYSzqARvJLxE0LQ6P+Lg=; b=DNGe78U0LrWfhyZ0bD9tkcexE4qS3a5HWgUBGhJSaJPa29uQQiL2pkpLehzalx4bso ajNUrM0vIvvfESwAHhmSYOOIt6EUGWRH4nUygbn/r8pat1EXhtf20lmTFTYl2FEQG5wM Y4hg4NgIa2R22X0Y65XMJyupxYX4ti+9QNt7CRM3HrA1Nym4WG796KxCsOk/1GnWYbEc qEy7GvKAy0KmTbJB+iOVopoLzS3nPK/Zmv+2erjAWZWxZuFGsvbDRlPxp/G5ErdK56MK 1oxUG+TsEFbeZYKBfo3KN7fzvfAKuFB9S+1PFoHbjvD5NFEHGc8LPwVqCItGWNxARYbu AYAw== X-Gm-Message-State: ANhLgQ25xa99U3gIhJcmzWubxGp2l+0SEWtqSXFSP0IWy1X//pLKAUo5 rnVOIEyJLoD0HpCFW8bLV5KgRWud8eJcxMUSC5RAqg== X-Google-Smtp-Source: ADFU+vvcU6T3lxFV7h8KYZLOMywnxliMph+u059zRhb8gvqvjA9ksaXJgEV5GLBbxPEwklid9b1upN98oO38ESPCWC4= X-Received: by 2002:aca:52c7:: with SMTP id g190mr3209181oib.144.1583259300891; Tue, 03 Mar 2020 10:15:00 -0800 (PST) MIME-Version: 1.0 References: <0a37bb7d-18a7-c43c-52a5-f13a34decf69@i-love.sakura.ne.jp> In-Reply-To: From: Shakeel Butt Date: Tue, 3 Mar 2020 10:14:49 -0800 Message-ID: Subject: Re: fs/buffer.c: WARNING: alloc_page_buffers while mke2fs To: Yang Shi Cc: Tetsuo Handa , Naresh Kamboju , linux-mm , Andrew Morton , Mel Gorman , Michal Hocko , Dan Schatzberg , Johannes Weiner 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 9:47 AM Yang Shi wrote: > > 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; > } > Maybe it's time to make memalloc_use_memcg() nesting safe.