From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754835AbYDWPiO (ORCPT ); Wed, 23 Apr 2008 11:38:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753980AbYDWPhz (ORCPT ); Wed, 23 Apr 2008 11:37:55 -0400 Received: from smtp-out.google.com ([216.239.33.17]:51268 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753995AbYDWPhy (ORCPT ); Wed, 23 Apr 2008 11:37:54 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=received:message-id:date:from:to:subject:cc:in-reply-to: mime-version:content-type:content-transfer-encoding: content-disposition:references; b=f10g2kE7lP08eFJwkq5HZaoqfRpygJvVwt15kJLq2Ag3RSFDSUNiv6Vpfkf3miwVl hZduCoAIs1QDHXT4T+nfA== Message-ID: <6599ad830804230837x48860632m7c41e425458ba6b3@mail.gmail.com> Date: Wed, 23 Apr 2008 08:37:45 -0700 From: "Paul Menage" To: "Cedric Le Goater" Subject: Re: [RFC PATCH 5/5] Add a Signal Control Group Subsystem Cc: "Matt Helsley" , Linux-Kernel , "Oren Laadan" , "Linus Torvalds" , "Pavel Machek" , linux-pm@lists.linux-foundation.org, "Linux Containers" In-Reply-To: <480F5321.9030008@fr.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080423142517.062433911@us.ibm.com> <20080423142518.703428301@us.ibm.com> <480F5321.9030008@fr.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 23, 2008 at 8:17 AM, Cedric Le Goater wrote: > Hello Matt ! > > > Add a signal control group subsystem that allows us to send signals to all tasks > > in the control group by writing the desired signal(7) number to the kill file. > > > > NOTE: We don't really need per-cgroup state, but control groups doesn't support > > stateless subsystems yet. > > > > Signed-off-by: Matt Helsley > > --- > > include/linux/cgroup_signal.h | 28 +++++++++ > > include/linux/cgroup_subsys.h | 6 + > > init/Kconfig | 6 + > > kernel/Makefile | 1 > > kernel/cgroup_signal.c | 129 ++++++++++++++++++++++++++++++++++++++++++ > > 5 files changed, 170 insertions(+) > > > I think there is a small race with new tasks entering the cgroup > while it's beeing killed, and a _fork ops would handle that. nop ? > I never saw the actual patch (what lists did it go out to?) but I suspect that this is one of those operations that's just going to be inherently racy, and that the API should guarantee to affect all tasks that are members of the group for the entirety of the operation, but with no guarantees about what happens to tasks that enter or leave in the meantime. Paul