From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id 5E0206B0214 for ; Sun, 4 Apr 2010 20:59:20 -0400 (EDT) Received: by pzk30 with SMTP id 30so2612665pzk.12 for ; Sun, 04 Apr 2010 17:59:18 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20100404195533.GA8836@logfs.org> References: <1270396784.1814.92.camel@barrios-desktop> <20100404160328.GA30540@ioremap.net> <1270398112.1814.114.camel@barrios-desktop> <20100404195533.GA8836@logfs.org> Date: Mon, 5 Apr 2010 09:59:18 +0900 Message-ID: Subject: Re: why are some low-level MM routines being exported? From: Minchan Kim Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: =?UTF-8?Q?J=C3=B6rn_Engel?= Cc: Evgeniy Polyakov , "Robert P. J. Day" , linux-mm@kvack.org List-ID: On Mon, Apr 5, 2010 at 4:55 AM, J=C3=B6rn Engel wrote: > On Mon, 5 April 2010 01:21:52 +0900, Minchan Kim wrote: >> > >> Until now, other file system don't need it. >> Why do you need? > > To avoid deadlocks. =C2=A0You tell logfs to write out some locked page, l= ogfs > determines that it needs to run garbage collection first. =C2=A0Garbage > collection can read any page. =C2=A0If it called find_or_create_page() fo= r > the locked page, you have a deadlock. Could you do it with add_to_page_cache and pagevec_lru_add_file? --=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/ . Don't email: email@kvack.org