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 8DB6BC3F2D1 for ; Tue, 3 Mar 2020 18:34:29 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 379552073B for ; Tue, 3 Mar 2020 18:34:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="QNfgLEmI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 379552073B 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 82C3F6B0005; Tue, 3 Mar 2020 13:34:28 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 7DDCA6B0006; Tue, 3 Mar 2020 13:34:28 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6F2546B0007; Tue, 3 Mar 2020 13:34:28 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0111.hostedemail.com [216.40.44.111]) by kanga.kvack.org (Postfix) with ESMTP id 53C5D6B0005 for ; Tue, 3 Mar 2020 13:34:28 -0500 (EST) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id DC3114995E3 for ; Tue, 3 Mar 2020 18:34:27 +0000 (UTC) X-FDA: 76554901374.08.title43_440c7cc91c059 X-HE-Tag: title43_440c7cc91c059 X-Filterd-Recvd-Size: 5408 Received: from mail-ed1-f65.google.com (mail-ed1-f65.google.com [209.85.208.65]) by imf27.hostedemail.com (Postfix) with ESMTP for ; Tue, 3 Mar 2020 18:34:27 +0000 (UTC) Received: by mail-ed1-f65.google.com with SMTP id dc19so5623520edb.10 for ; Tue, 03 Mar 2020 10:34:27 -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=5omRyQcmriaGK7OAXN5qyuhfXu84/FLgSW5TccFkSVU=; b=QNfgLEmIDe3VtydlrIQXJLDRN7p/LXNCZSOpLWYEMdrJ6dcIV1A0crgEW2twHtzYQp V1g0/lx0Lev2d185QpxP+h2whOG2dH7CcLy7RV7/a+TXWbbgru63Oe4mlTxnChTt7ka/ stdZsFfaBDNnOrIvDq5RfzidO3gdCjHqZrKcyawZjLTaAj5BEC6tFj8gqRgopi6NMR9O sFqah0pswsrSA1G4wW7ISni1+x4bpFvm/c70qBQZMBpBdRjh1qKA4MTFLTlS0nVlZCe+ wFxk54vp1fBWyhc6BJE6PwgiTqtQn11oZwWi1Ftn2OyCXbrh+3/96h+CuPSbkZJ++QJv 7GIA== 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=5omRyQcmriaGK7OAXN5qyuhfXu84/FLgSW5TccFkSVU=; b=bhe6WQb05+Iai98JJ2tFEC0n0DfOkdZc1GMKl0w+H293fgg9/PoULmZxTF4iGWaCps 5liMrsHIBSGnDReIO8Yt7BXN4FU89kt+ApdjaBuTGfWR7aeR6hDQ8Wsy6WN1wzp7Us1s urgSFOIK3O35YtA4rXZYzle06Y6OstLjsN8TUys3kUbI67A8HA5eXW9F4NGN1T3ICtYq o8mN2++l1DrnMrtmnJkhT4WNZ3HBpw12EETRHKqvDrDw/oBjlmfpR1JZbTuynur7dzAV gnuL0shl24hIYfWWyBHh2tZqseOmnN/hi3RXtXCj+liu2HZz/R2DTGHC2qPNsd00U1xo aYww== X-Gm-Message-State: ANhLgQ1F+P24ge89IDPbRiAk6iPWN1vR8EP+q83fYV1CkSmajDNDUyLr 3MT/tXnhYb1rRmi+x87u6x3IiWOuwRIfmFnrwFc= X-Google-Smtp-Source: ADFU+vtMInI0MN9Rd9JkvfNk9mvqItdWJqwOrVSZQed0jKSZpiOuxCrC6ZS6IJMYRyhPekiVFfu374wz1S5AX5ddtcA= X-Received: by 2002:a50:d65b:: with SMTP id c27mr5260129edj.206.1583260466459; Tue, 03 Mar 2020 10:34:26 -0800 (PST) MIME-Version: 1.0 References: <0a37bb7d-18a7-c43c-52a5-f13a34decf69@i-love.sakura.ne.jp> In-Reply-To: From: Yang Shi Date: Tue, 3 Mar 2020 10:34:09 -0800 Message-ID: Subject: Re: fs/buffer.c: WARNING: alloc_page_buffers while mke2fs To: Shakeel Butt 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 10:15 AM Shakeel Butt wrote: > > 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. That would be preferred. Maybe like: static inline void memalloc_use_memcg(struct mem_cgroup *memcg, struct mem_cgroup *saved)