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_INVALID, DKIM_SIGNED,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 36034C49361 for ; Wed, 16 Jun 2021 12:31:47 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 875AB60FE8 for ; Wed, 16 Jun 2021 12:31:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 875AB60FE8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=szeredi.hu Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0C4246B006C; Wed, 16 Jun 2021 08:31:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 04DB06B006E; Wed, 16 Jun 2021 08:31:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E09706B0070; Wed, 16 Jun 2021 08:31:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id AAB686B006C for ; Wed, 16 Jun 2021 08:31:45 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 18E8A180AD807 for ; Wed, 16 Jun 2021 12:31:45 +0000 (UTC) X-FDA: 78259523370.25.4B18CA9 Received: from mail-vs1-f50.google.com (mail-vs1-f50.google.com [209.85.217.50]) by imf24.hostedemail.com (Postfix) with ESMTP id 04ABDA000245 for ; Wed, 16 Jun 2021 12:31:33 +0000 (UTC) Received: by mail-vs1-f50.google.com with SMTP id x13so900975vsf.11 for ; Wed, 16 Jun 2021 05:31:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=szeredi.hu; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=drmK1l9ZAYnCw4AU0VAPo5P0a5EA+tE1PwSwVaZH2ns=; b=TrwK1cHrsTvLbt/FsI5y2KOeR9N0daQjCPIw+/ozCkYGOE/EVt8KrmaLmnupNOtalm VXXH3I0Qf90gFbYuvh8jpSQ2LnIpzh4EqKaG3woAarOzy1N82xbdDqd9Aft4gaFRVi/4 /jYSYjCow99Y4ZGQvEFEMdWUIpAfRpQLdqkFY= 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=drmK1l9ZAYnCw4AU0VAPo5P0a5EA+tE1PwSwVaZH2ns=; b=LNs6RzQaTxmVCYtBySIei1gKdgcG4P+4kGhh/NA6dBdNV2I9vrxDY3nJLldFfYFEGI P89Urrn6JrrasqKlun4QxykjOy+a3H6uO1z5tSkGi7TnN84sl7Fbzct5X8EcYmc3yufS r/F8tN5M8dtaHCRlHsNty5CaAnrM5tqsn0WVi1Dt51J/Pi51HhEV8V2PqJc+B05XsmV3 G2HMy0qWDYDzx2s6YJOmrLw6K3l2IPs9HVbMbZfVoOYp4m0HfLBHtncEElRoGZ8qoAw0 XtGNrdVhbvXPhYzRRbdIRhePOGIWcVmMbsrhEsNWxi/8t4QS1EpPRg/P0tq/NNju01yu axlQ== X-Gm-Message-State: AOAM5311T4J/MUvWs8aLhl+G0bXBMuIoSJPYlkizzOI1QiMgwPZ7XKr0 YylFRaX39WVy6sMhhCpwGahkV0lkxtV/DD5RXYWWUA== X-Google-Smtp-Source: ABdhPJwU4TG3bflQtBUIV1kT17BBBRLLSwbJ/amzK0gyVEHbf8wXwD3Cw6rexMzF/avWgOdUz0MOKdYODW+XsmXc5+c= X-Received: by 2002:a67:bb14:: with SMTP id m20mr10648645vsn.0.1623846703321; Wed, 16 Jun 2021 05:31:43 -0700 (PDT) MIME-Version: 1.0 References: <016b2fe2-0d52-95c9-c519-40b14480587a@gmail.com> In-Reply-To: <016b2fe2-0d52-95c9-c519-40b14480587a@gmail.com> From: Miklos Szeredi Date: Wed, 16 Jun 2021 14:31:32 +0200 Message-ID: Subject: Re: Possible bogus "fuse: trying to steal weird page" warning related to PG_workingset. To: Matthew Wilcox Cc: linux-mm , linux-fsdevel@vger.kernel.org, Thomas Lindroth Content-Type: text/plain; charset="UTF-8" Authentication-Results: imf24.hostedemail.com; dkim=none ("invalid DKIM record") header.d=szeredi.hu header.s=google header.b=TrwK1cHr; dmarc=none; spf=pass (imf24.hostedemail.com: domain of miklos@szeredi.hu designates 209.85.217.50 as permitted sender) smtp.mailfrom=miklos@szeredi.hu X-Rspamd-Server: rspam02 X-Stat-Signature: sp3ca3weak63irpez4tqgueei1zn6dwn X-Rspamd-Queue-Id: 04ABDA000245 X-HE-Tag: 1623846693-665905 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000013, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, 14 Jun 2021 at 11:56, Thomas Lindroth wrote: > > Hi. I recently upgraded to kernel series 5.10 from 4.19 and I now get warnings like > this in dmesg: > > page:00000000e966ec4e refcount:1 mapcount:0 mapping:0000000000000000 index:0xd3414 pfn:0x14914a > flags: 0x8000000000000077(locked|referenced|uptodate|lru|active|workingset) > raw: 8000000000000077 ffffdc7f4d312b48 ffffdc7f452452c8 0000000000000000 > raw: 00000000000d3414 0000000000000000 00000001ffffffff ffff8fd080123000 > page dumped because: fuse: trying to steal weird page > > The warning in fuse_check_page() doesn't check for PG_workingset which seems to be what > trips the warning. I'm not entirely sure this is a bogus warning but there used to be > similar bogus warnings caused by a missing PG_waiters check. The PG_workingset > page flag was introduced in 4.20 which explains why I get the warning now. > > I only get the new warning if I do writes to a fuse fs (mergerfs) and at the same > time put the system under memory pressure by running many qemu VMs. AFAICT fuse is trying to steal a pagecache page from a pipe buffer created by splice(2). The page looks okay, but I have no idea what PG_workingset means in this context. Matthew, can you please help? Thanks, Miklos