From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756787AbYFLRag (ORCPT ); Thu, 12 Jun 2008 13:30:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755932AbYFLRaO (ORCPT ); Thu, 12 Jun 2008 13:30:14 -0400 Received: from mx1.redhat.com ([66.187.233.31]:51181 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755651AbYFLRaN (ORCPT ); Thu, 12 Jun 2008 13:30:13 -0400 Date: Thu, 12 Jun 2008 13:29:52 -0400 From: Rik van Riel To: Nick Piggin Cc: linux-kernel@vger.kernel.org, Andrew Morton , Lee Schermerhorn , Kosaki Motohiro , linux-mm@kvack.org, Eric Whitney Subject: Re: [PATCH -mm 14/24] Ramfs and Ram Disk pages are unevictable Message-ID: <20080612132952.568226f6@cuia.bos.redhat.com> In-Reply-To: <200806121054.19253.nickpiggin@yahoo.com.au> References: <20080611184214.605110868@redhat.com> <20080611184339.693975681@redhat.com> <200806121054.19253.nickpiggin@yahoo.com.au> Organization: Red Hat, Inc X-Mailer: Claws Mail 3.3.1 (GTK+ 2.12.5; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 12 Jun 2008 10:54:18 +1000 Nick Piggin wrote: > On Thursday 12 June 2008 04:42, Rik van Riel wrote: > > From: Lee Schermerhorn > > > > Christoph Lameter pointed out that ram disk pages also clutter the > > LRU lists. When vmscan finds them dirty and tries to clean them, > > the ram disk writeback function just redirties the page so that it > > goes back onto the active list. Round and round she goes... > This isn't the case for brd any longer. It doesn't use the buffer > cache as its backing store, so the buffer cache is reclaimable. What does that mean? I know that pages of files that got paged into the page cache from the ramdisk can be evicted (back to the ram disk), but how do the brd pages themselves behave? -- All Rights Reversed