From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760572AbXEaR7F (ORCPT ); Thu, 31 May 2007 13:59:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757244AbXEaR6z (ORCPT ); Thu, 31 May 2007 13:58:55 -0400 Received: from smtp1.linux-foundation.org ([207.189.120.13]:41752 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755119AbXEaR6y (ORCPT ); Thu, 31 May 2007 13:58:54 -0400 Date: Thu, 31 May 2007 10:58:42 -0700 From: Andrew Morton To: Pavel Emelianov Cc: Balbir Singh , Paul Menage , Linux Kernel Mailing List , devel@openvz.org, Kirill Korotaev Subject: Re: [PATCH 8/8] Per-container pages reclamation Message-Id: <20070531105842.0728f577.akpm@linux-foundation.org> In-Reply-To: <465EA4FF.1000904@openvz.org> References: <465D9739.8070209@openvz.org> <465D9B62.5050507@openvz.org> <20070530144737.56456aaf.akpm@linux-foundation.org> <465EA4FF.1000904@openvz.org> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.6; 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 Thu, 31 May 2007 14:35:43 +0400 Pavel Emelianov wrote: > > Would I be correct in guessing that pages which are on the > > per-rss-container lists are also eligible for reclaim off the traditional > > page LRUs? If so, how does that work? When a page gets freed off the > > Yes. All the pages are accessible from booth - global and per-container > LRU lists and reclamation can be performed from booth. > > > per-zone LRUs does it also get removed from the per-rss_container LRU? But > > how can this be right? > > I don't get your idea here. If we have a page which is on the zone LRU with refcount=1 and someone does put_page() on it, we will take that page off the zone LRU and then actually free the page. I am assuming that your patches change that logic so that we will also remove that page from the per-container LRU at the same time? If so, the problem which I see is that, under rare circumstances, that final put_page() will occur from interrupt context. Hence we would be trying to remove the page from the per-container LRU at interrupt time. But the locks which you have in there are not suited for taking from interrupt context.