Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932119AbXBKMOD (ORCPT ); Sun, 11 Feb 2007 07:14:03 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932078AbXBKMOD (ORCPT ); Sun, 11 Feb 2007 07:14:03 -0500 Received: from mail-gw3.sa.ew.hu ([212.108.200.82]:52549 "EHLO mail-gw3.sa.ew.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753181AbXBKMOB (ORCPT ); Sun, 11 Feb 2007 07:14:01 -0500 To: rsc@swtch.com CC: akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org In-reply-to: (rsc@swtch.com) Subject: Re: [PATCH] fix quadratic behavior of shrink_dcache_parent() References: <20070209160055.bbd20c9f.akpm@linux-foundation.org> Message-Id: From: Miklos Szeredi Date: Sun, 11 Feb 2007 13:13:23 +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1349 Lines: 33 > > Unfortunately this patch doesn't completely solve this problem, since > > the system will still be hosed due to all memory being used up by > > dentries. And I bet the OOM killer won't find the real target (du) > > but will kill anything before that. > > > > So the second part of the problem is to somehow limit the number of > > dentries used. Not easy... > > At least with this patch (if I am reading it correctly), once the offending > culprit is identified and the programs are killed off, everything will go > back to normal without a reboot. Yes, it's basically a "normal" OOM situation. What makes it worse than usual, is that it's _kernel_ memory being used up which is not attributed to any process. So from the OOM killer's point of view it looks like none of the userspace programs are responsible for the OOM, and it will just select targets randomly. By the time it has come to the actual culprits (the filesystem daemon and 'du') it will have killed almost everything useful. So it's definitely better than without the patch, but still has room for improvement. Thanks, Miklos - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/