From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id CF6A06B0089 for ; Tue, 4 Jan 2011 23:53:05 -0500 (EST) Received: by iyj17 with SMTP id 17so14605540iyj.14 for ; Tue, 04 Jan 2011 20:53:04 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20110104161805.GE3120@balbir.in.ibm.com> References: <20110104161805.GE3120@balbir.in.ibm.com> Date: Wed, 5 Jan 2011 13:53:04 +0900 Message-ID: Subject: Re: [PATCH v2 0/7] Change page reference handling semantic of page cache From: Minchan Kim Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: balbir@linux.vnet.ibm.com Cc: Andrew Morton , linux-mm , LKML , KAMEZAWA Hiroyuki , Hugh Dickins List-ID: Hi Balbir, On Wed, Jan 5, 2011 at 1:18 AM, Balbir Singh wr= ote: > * MinChan Kim [2011-01-03 00:44:29]: > >> Now we increases page reference on add_to_page_cache but doesn't decreas= e it >> in remove_from_page_cache. Such asymmetric makes confusing about >> page reference so that caller should notice it and comment why they >> release page reference. It's not good API. >> >> Long time ago, Hugh tried it[1] but gave up of reason which >> reiser4's drop_page had to unlock the page between removing it from >> page cache and doing the page_cache_release. But now the situation is >> changed. I think at least things in current mainline doesn't have any >> obstacles. The problem is fs or somethings out of mainline. >> If it has done such thing like reiser4, this patch could be a problem bu= t >> they found it when compile time since we remove remove_from_page_cache. >> >> [1] http://lkml.org/lkml/2004/10/24/140 >> >> The series configuration is following as. >> >> [1/7] : This patch introduces new API delete_from_page_cache. >> [2,3,4,5/7] : Change remove_from_page_cache with delete_from_page_cache. >> Intentionally I divide patch per file since someone might have a concern >> about releasing page reference of delete_from_page_cache in >> somecase (ex, truncate.c) >> [6/7] : Remove old API so out of fs can meet compile error when build ti= me >> and can notice it. >> [7/7] : Change __remove_from_page_cache with __delete_from_page_cache, t= oo. >> In this time, I made all-in-one patch because it doesn't change old beha= vior >> so it has no concern. Just clean up patch. >> > > Could you please describe any testing done, was it mostly functional? I didn't test it since I think it's okay as a code review. Do you find any faults or guess it? Anyway, I should have tested it before sending patches. we are now -rc8 and Andrew doesn't held a patch. So I will test it until he grab a patch. Thanks, > > -- > =A0 =A0 =A0 =A0Three Cheers, > =A0 =A0 =A0 =A0Balbir > --=20 Kind regards, Minchan Kim -- 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/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org