From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 17 Sep 2007 16:32:57 +0200 From: Peter Zijlstra Subject: Re: VM/VFS bug with large amount of memory and file systems? Message-ID: <20070917163257.331c7605@twins> In-Reply-To: <13126578-A4F8-43EA-9B0D-A3BCBFB41FEC@cam.ac.uk> References: <1189850897.21778.301.camel@twins> <20070915035228.8b8a7d6d.akpm@linux-foundation.org> <13126578-A4F8-43EA-9B0D-A3BCBFB41FEC@cam.ac.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Anton Altaparmakov Cc: Andrew Morton , Linux Kernel Mailing List , Linux Memory Management List , marc.smith@esmail.mcc.edu List-ID: On Mon, 17 Sep 2007 15:04:05 +0100 Anton Altaparmakov wrote: > They files > are attached this time rather than inlined so people don't complain > about line wrapping! (No doubt people will not complain about them > being attached! )-:) I switched mailer after I learnt about flowed stuffs. Still, appreciated. > If I read it correctly it appears all of low memory is eaten up by > buffer_heads. > > > # name > > : tunables : slabdata > labs> > buffer_head 12569528 12569535 56 67 1 : tunables > 120 60 8 : > slabdata 187605 187605 0 > > > That is 671MiB of low memory in buffer_heads. > > But why is the kernel not reclaiming them by getting rid of the page > cache pages they are attached to or even leaving the pages around but > killing their buffers? Well, you see, you have this very odd configuration where: 11GB highmem 1GB normal pagecache pages go into highmem buggerheads go into normal I'm guessing there is no pressure at all on zone_highmem so the kernel will not try to reclaim pagecache. And because the pagecache pages are happily sitting there, the buggerheads are pinned and do not get reclaimed. -- 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