Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762885AbZAUDRA (ORCPT ); Tue, 20 Jan 2009 22:17:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754191AbZAUDQv (ORCPT ); Tue, 20 Jan 2009 22:16:51 -0500 Received: from smtp-out.google.com ([216.239.33.17]:60533 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754108AbZAUDQu (ORCPT ); Tue, 20 Jan 2009 22:16:50 -0500 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=mime-version:in-reply-to:references:date:message-id:subject:from:to: cc:content-type:content-transfer-encoding: x-gmailtapped-by:x-gmailtapped; b=D9j5jiKW+R5FFsZgtcucvq2qzkf98wunSLzubMYG8/e6LrqOWgvHB/RPJwjut5Inq CFiG5wx6bKnddxFLOLJ9g== MIME-Version: 1.0 In-Reply-To: <20090120120728.9be81131.kamezawa.hiroyu@jp.fujitsu.com> References: <20090109143226.b79d21b4.kamezawa.hiroyu@jp.fujitsu.com> <6599ad830901082226h6d47053cp801dafb67b6e2bc9@mail.gmail.com> <20090109153219.dd8c153d.kamezawa.hiroyu@jp.fujitsu.com> <1232072445.7955.40.camel@localhost> <6599ad830901191752o53926bdbve593301aeff7330f@mail.gmail.com> <20090120120728.9be81131.kamezawa.hiroyu@jp.fujitsu.com> Date: Tue, 20 Jan 2009 19:16:42 -0800 Message-ID: <6599ad830901201916o36e5e23bse440025618495ace@mail.gmail.com> Subject: Re: [RFC][PATCH] NOOP cgroup subsystem From: Paul Menage To: KAMEZAWA Hiroyuki Cc: matthltc@us.ibm.com, "linux-kernel@vger.kernel.org" , "lizf@cn.fujitsu.com" , "akpm@linux-foundation.org" , Containers Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-GMailtapped-By: 172.28.16.76 X-GMailtapped: menage Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1312 Lines: 31 On Mon, Jan 19, 2009 at 7:07 PM, KAMEZAWA Hiroyuki wrote: > In my understanding, "sending signal" requires some protocol/order in userland. > > Assume that users has to send signal in following order > Application A -> Application B -> Application C..... > and may have problems sending signals in following order > Application B -> Application A ->..... In a case like that, a user would have to do their own signal sending rather than letting the "signal" subsystem handle it. The signal subsystem is more useful for doing things like sending less-refined signals like SIGSTOP or SIGKILL to all tasks in a cgroup. > multilply-mounted means its own hierachy can be created per mount point ? Yes. > If so, signal subsystem can be used instead of noop. Supporting mounting a subsystem in multiple different hierarchies would pretty much involve supporting mounting a hierarchy with no subsystems (at least in the way I envisaged it), so you wouldn't need any subsystem in that case if you were just trying to do grouping. Paul -- 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/