From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f48.google.com (mail-pa0-f48.google.com [209.85.220.48]) by kanga.kvack.org (Postfix) with ESMTP id A31136B0253 for ; Sun, 15 Nov 2015 20:38:34 -0500 (EST) Received: by pacej9 with SMTP id ej9so50645207pac.2 for ; Sun, 15 Nov 2015 17:38:34 -0800 (PST) Received: from mail-pa0-x22d.google.com (mail-pa0-x22d.google.com. [2607:f8b0:400e:c03::22d]) by mx.google.com with ESMTPS id jw6si46794715pbc.214.2015.11.15.17.38.34 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 15 Nov 2015 17:38:34 -0800 (PST) Received: by pacej9 with SMTP id ej9so50644994pac.2 for ; Sun, 15 Nov 2015 17:38:33 -0800 (PST) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 9.0 \(3094\)) Subject: Re: [PATCH] mm: change may_enter_fs check condition From: yalin wang In-Reply-To: <20151113153615.GE2632@dhcp22.suse.cz> Date: Mon, 16 Nov 2015 09:38:32 +0800 Content-Transfer-Encoding: quoted-printable Message-Id: <77563C7C-973D-40CF-8AC3-FA550D349BE2@gmail.com> References: <1447415255-832-1-git-send-email-yalin.wang2010@gmail.com> <5645D10C.701@suse.cz> <20151113153615.GE2632@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Vlastimil Babka , Andrew Morton , vdavydov@parallels.com, hannes@cmpxchg.org, mgorman@techsingularity.net, tj@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org > On Nov 13, 2015, at 23:36, Michal Hocko wrote: >=20 > On Fri 13-11-15 13:01:16, Vlastimil Babka wrote: >> On 11/13/2015 12:47 PM, yalin wang wrote: >>> Add page_is_file_cache() for __GFP_FS check, >>> otherwise, a Pageswapcache() && PageDirty() page can always be write >>> back if the gfp flag is __GFP_FS, this is not the expected behavior. >>=20 >> I'm not sure I understand your point correctly *), but you seem to = imply >> that there would be an allocation that has __GFP_FS but doesn't have >> __GFP_IO? Are there such allocations and does it make sense? >=20 > No it doesn't. There is a natural layering here and __GFP_FS = allocations > should contain __GFP_IO. >=20 > The patch as is makes only little sense to me. Are you seeing any = issue > which this is trying to fix? mm.. i don=E2=80=99t see issue for this part , just feel confuse when i see code about this part , then i make a patch for this . i am not sure if __GFP_FS will make sure __GFP_IO flag must be always = set. if it is , i think can add comment here to make people clear . :) Thanks -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org