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=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FSL_HELO_FAKE,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 0F909C35242 for ; Tue, 11 Feb 2020 03:50:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DB1CA206D7 for ; Tue, 11 Feb 2020 03:50:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581393015; bh=KlTBGHzBwEEpW5M1NxWMEwp4ci+LaUkSpctlqT3gaoU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=U1Y+LsHAoEXXeICN9lESI48CtQkQgTXFyIMkDYyRRwaCwI/MaaVr6Lh/tbF8vYcyb MTW2jyTKwSaTMrvf19dAWvmhuPoT3EAOpIwdtFAzssJAtCOb9AbMTHbgRhaF0Ucc/o L2G1v9RJNcpbwUgwyCVg2pq4kTBD5SmewupSmOnU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727830AbgBKDuO (ORCPT ); Mon, 10 Feb 2020 22:50:14 -0500 Received: from mail-pj1-f68.google.com ([209.85.216.68]:34931 "EHLO mail-pj1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727045AbgBKDuO (ORCPT ); Mon, 10 Feb 2020 22:50:14 -0500 Received: by mail-pj1-f68.google.com with SMTP id q39so650297pjc.0 for ; Mon, 10 Feb 2020 19:50:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=3nqU/O+TdSRMSc5Iylpi8VTithOiRFDrm96y3sARYI8=; b=UTmr/EQuGdLNwCEGo3xt2whj2Yp4ofvsR+3DHJ7aVQ8p/ULL5OMNfxyp5IEnQIho2u LO+fd3c6YenOeygz1cI14DtDIG+zN7p9dGXhVoOEziuLFScOIE68s+BGISEdEOV0YUvS cLbJhnG1ZkEsf41lZZbvwUZenwkvDv6Fy+pxK+v8X91/2BR/8EHyKoRpRkQM1KmAMxzA z9Zgo8K+2c+1QzdiiMSh/OCq1h3UljUfsBL+TcIbfSfTtfygy1XL/ckU195GDeOd9n8C nDwnLaRgcAQji405YM4nPYkGlpZsg3iIAGZS9X19QjdWDtuO7iCY5UrIlt2uYOG+hRwN XUjg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=3nqU/O+TdSRMSc5Iylpi8VTithOiRFDrm96y3sARYI8=; b=SDIIyE3VyjCk3jxABFOK258EEebe4Bkw7Km1/+HfBrWb7cJUDeRi4CWIEgszUgVw2X tHs2tyIpYaOUKqUpESgxCepBHoltBgXSJPVItSrojurDocfpWATi8cSBENlCykcCOJ8V zcdUFGtntzEWBj0NHmNMFwyjfB3fZLsuji7kwhShVNo4uHMZSLgcu4Yojp+T7YDK478e pRzgjSn+sCGfZLesQ+INKxVW+mMMgSzzZMP+/Ir7ZyLmCtaiFvAeA45jty6/5NdIVpUh Hdb374Tzm9yzU/f610oqwcyGLh4XizaLZ2mjfy23vOuUMMh38lB0UfhyLRuPw2Oxmsjs VMnw== X-Gm-Message-State: APjAAAUo8L6tkQZwPJ5q5KpnIfuhISAkQC9wJ6ptNPTkJppL/2LRycud X3g+yUwJtNR3ODsvgM+SlQPA00aJ X-Google-Smtp-Source: APXvYqzyPQ4s8RFroOe8AaydMzrU2A1MfwzgXDPCfacBXUeMfGbzaCVJHpi/MDUaQjcrGclvQkMvXA== X-Received: by 2002:a17:90a:e291:: with SMTP id d17mr1375367pjz.116.1581393006817; Mon, 10 Feb 2020 19:50:06 -0800 (PST) Received: from google.com ([2620:15c:211:1:3e01:2939:5992:52da]) by smtp.gmail.com with ESMTPSA id e38sm1520811pgm.82.2020.02.10.19.50.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Feb 2020 19:50:05 -0800 (PST) Date: Mon, 10 Feb 2020 19:50:04 -0800 From: Minchan Kim To: Matthew Wilcox Cc: Andrew Morton , linux-mm , Josef Bacik , Johannes Weiner , Jan Kara , LKML Subject: Re: [PATCH] mm: fix long time stall from mm_populate Message-ID: <20200211035004.GA242563@google.com> References: <20200211001958.170261-1-minchan@kernel.org> <20200211011021.GP8731@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200211011021.GP8731@bombadil.infradead.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 10, 2020 at 05:10:21PM -0800, Matthew Wilcox wrote: > On Mon, Feb 10, 2020 at 04:19:58PM -0800, Minchan Kim wrote: > > filemap_fault > > find a page form page(PG_uptodate|PG_readahead|PG_writeback) > > Uh ... That shouldn't be possible. Please see shrink_page_list. Vmscan uses PG_reclaim to accelerate page reclaim when the writeback is done so the page will have both flags at the same time and the PG reclaim could be regarded as PG_readahead in fault conext. > > /* > * Same bit is used for PG_readahead and PG_reclaim. > */ > if (PageWriteback(page)) > return; > > ClearPageReadahead(page); >