From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755320Ab1JSXbN (ORCPT ); Wed, 19 Oct 2011 19:31:13 -0400 Received: from tango.0pointer.de ([85.214.72.216]:52053 "EHLO tango.0pointer.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755009Ab1JSXbM (ORCPT ); Wed, 19 Oct 2011 19:31:12 -0400 Date: Thu, 20 Oct 2011 01:31:11 +0200 From: Lennart Poettering To: Paul Menage Cc: Kay Sievers , linux-kernel@vger.kernel.org, harald@redhat.com, david@fubar.dk, greg@kroah.com Subject: Re: A =?utf-8?Q?Plumber=E2=80=99?= =?utf-8?Q?s?= Wish List for Linux Message-ID: <20111019233111.GE32295@tango.0pointer.de> References: <1317943022.1095.25.camel@mop> <20111019230347.GA32295@tango.0pointer.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Red Hat, Inc. X-Campaign-1: () ASCII Ribbon Campaign X-Campaign-2: / Against HTML Email & vCards - Against Microsoft Attachments User-Agent: Leviathan/19.8.0 [zh] (Cray 3; I; Solaris 4.711; Console) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 19.10.11 16:09, Paul Menage (paul@paulmenage.org) wrote: > On Wed, Oct 19, 2011 at 4:03 PM, Lennart Poettering > wrote: > > > > For our systemd usecase a cgroup.signal file would not be useful. This > > is because we actually kill all members of the service's cgroup plus the > > main process of the service, which is usually also in the service's > > cgroup but sometimes isn't (for example: when the user logs in, the > > whole /sbin/login process ends up in the user's session cgroup, and is > > removed from the original service cgroup). Since we want to avoid > > killing the main service process twice in the case where it isn't in the > > servce cgroup we'd hence prefer to have some fork throttling logic in > > place, so that we can kill members flexibly in accordance with these > > rules. > > By fork-throttling, do you just mean "0 or unlimited", or would you > actually want some kind of rate-limited throttling? If the former, > than I agree with Frederick that his task counter should solve that > problem. Given that shutting down some services might involve forking off a few things (think: a shell script handling shutdown which forks off a couple of shell utilities) we'd want something that is between "from now on no forking at all" and "unlimited forking". This could be done in many different ways: we'd be happy if we could do time-based rate limiting, but we'd also be fine with defining a certain budget of additional forks a cgroup can do (i.e. "from now on you can do 50 more forks, then you'll get EPERM). Lennart -- Lennart Poettering - Red Hat, Inc.