From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757517Ab3HGOBK (ORCPT ); Wed, 7 Aug 2013 10:01:10 -0400 Received: from mail-vb0-f42.google.com ([209.85.212.42]:65428 "EHLO mail-vb0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752893Ab3HGOBH (ORCPT ); Wed, 7 Aug 2013 10:01:07 -0400 Date: Wed, 7 Aug 2013 10:01:03 -0400 From: Tejun Heo To: Michal Hocko Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Johannes Weiner , KAMEZAWA Hiroyuki , Andrew Morton , "Kirill A. Shutemov" , Anton Vorontsov Subject: Re: [PATCH 2/3] memcg: Limit the number of events registered on oom_control Message-ID: <20130807140103.GH27006@htj.dyndns.org> References: <1375874907-22013-1-git-send-email-mhocko@suse.cz> <1375874907-22013-2-git-send-email-mhocko@suse.cz> <20130807130836.GB27006@htj.dyndns.org> <20130807133746.GI8184@dhcp22.suse.cz> <20130807134741.GF27006@htj.dyndns.org> <20130807135734.GK8184@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130807135734.GK8184@dhcp22.suse.cz> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 07, 2013 at 03:57:34PM +0200, Michal Hocko wrote: > On Wed 07-08-13 09:47:41, Tejun Heo wrote: > > Hello, > > > > On Wed, Aug 07, 2013 at 03:37:46PM +0200, Michal Hocko wrote: > > > > It isn't different from listening from epoll, for example. > > > > > > epoll limits the number of watchers, no? > > > > Not that I know of. It'll be limited by max open fds but I don't > > think there are other limits. > > max_user_watches seems to be a limit (4% of lowmem in maximum). That's per *user* not per event source. The problem here is creating a global (across securit domains) resource shared by all users. -- tejun