From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nick Piggin Subject: Re: [PATCH -mm 14/24] Ramfs and Ram Disk pages are unevictable Date: Fri, 13 Jun 2008 03:37:56 +1000 References: <20080611184214.605110868@redhat.com> <200806121054.19253.nickpiggin@yahoo.com.au> <20080612132952.568226f6@cuia.bos.redhat.com> In-Reply-To: <20080612132952.568226f6@cuia.bos.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200806130337.57118.nickpiggin@yahoo.com.au> Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: linux-kernel@vger.kernel.org, Andrew Morton , Lee Schermerhorn , Kosaki Motohiro , linux-mm@kvack.org, Eric Whitney List-ID: On Friday 13 June 2008 03:29, Rik van Riel wrote: > 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? That your patch is obsolete. > 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? They are not reclaimable. But they have nothing (directly) to do with brd's i_mapping address space, nor are they put on any LRU lists. -- 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