From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 9 Sep 2001 09:15:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 9 Sep 2001 09:15:26 -0400 Received: from ns.ithnet.com ([217.64.64.10]:11020 "HELO heather.ithnet.com") by vger.kernel.org with SMTP id ; Sun, 9 Sep 2001 09:15:17 -0400 Date: Sun, 9 Sep 2001 15:15:09 +0200 From: Stephan von Krawczynski To: Alan Cox Cc: mcelrath@draal.physics.wisc.edu, linux-kernel@vger.kernel.org Subject: Re: "Cached" grows and grows and grows... Message-Id: <20010909151509.6a0c7d68.skraw@ithnet.com> In-Reply-To: In-Reply-To: <20010908184758.696bb9d1.skraw@ithnet.com> Organization: ith Kommunikationstechnik GmbH X-Mailer: Sylpheed version 0.6.1 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 8 Sep 2001 18:14:46 +0100 (BST) Alan Cox wrote: > > // printk(KERN_ERR "__alloc_pages: %lu-order allocation failed.\n", order) > > return NULL; > > > > If there is no printk, you will obviously not notice the problem. You can bet > > your car on not "seeing the problem". > > That printk is commented out because its pointless and bogus noise. It just > causes confused bug reporting. The stuff that matters is cache sizes > shrinking back when we need memory not slowly eating the computer alive. Hm, I guess I had to find out, that you've the same problem than linus' tree, only on "the other side of the street". This is a meminfo from a 2.4.9-ac9 kernel working one day, and then going crazy on too low mem. "Going crazy" here means that kswapd took virtually over the cpu(s) and swapped the hell out the machine: (BTW you can see that swap did not really grow, but seems to get in and out permanently) total: used: free: shared: buffers: cached: Mem: 921706496 894324736 27381760 4096 783917056 29102080 Swap: 271392768 13185024 258207744 MemTotal: 900104 kB MemFree: 26740 kB MemShared: 4 kB Buffers: 765544 kB Cached: 15744 kB SwapCached: 12676 kB Active: 502132 kB Inact_dirty: 291836 kB Inact_clean: 0 kB Inact_target: 80 kB HighTotal: 0 kB HighFree: 0 kB LowTotal: 900104 kB LowFree: 26740 kB SwapTotal: 265032 kB SwapFree: 252156 kB You are right: page cache shrunk. You are wrong: it does _not_ work, because now buffers increased and obviously cannot be shrunk to allow "normal" applications to run. I could not even shutdown the machine correctly. It looks like a deadlock in vm to me. I switched back to Linus' tree, because it does have problems, but is not dead within one day. Regards, Stephan