Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751524AbaDOXJO (ORCPT ); Tue, 15 Apr 2014 19:09:14 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42137 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750790AbaDOXJH (ORCPT ); Tue, 15 Apr 2014 19:09:07 -0400 Subject: Re: [PATCH 2/2] net: Implement SO_PASSCGROUP to enable passing cgroup path From: Simo Sorce To: Andy Lutomirski Cc: Vivek Goyal , "linux-kernel@vger.kernel.org" , cgroups@vger.kernel.org, Network Development , "David S. Miller" , Tejun Heo , lpoetter@redhat.com, kay@redhat.com, dwalsh@redhat.com In-Reply-To: References: <1397596546-10153-1-git-send-email-vgoyal@redhat.com> <1397596546-10153-3-git-send-email-vgoyal@redhat.com> Content-Type: text/plain; charset="UTF-8" Date: Tue, 15 Apr 2014 19:09:00 -0400 Message-ID: <1397603340.19767.362.camel@willson.li.ssimo.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2014-04-15 at 14:53 -0700, Andy Lutomirski wrote: > On Tue, Apr 15, 2014 at 2:15 PM, Vivek Goyal wrote: > > This patch implements socket option SO_PASSCGROUP along the lines of > > SO_PASSCRED. > > > > If SO_PASSCGROUP is set, then recvmsg() will get a control message > > SCM_CGROUP which will contain the cgroup path of sender. This cgroup > > belongs to first mounted hierarchy in the sytem. > > > > SCM_CGROUP control message can only be received and sender can not send > > a SCM_CGROUP message. Kernel automatically generates one if receiver > > chooses to receive one. > > > > This works both for unix stream and datagram sockets. > > > > cgroup information is passed only if either the sender or receiver has > > SO_PASSCGROUP option set. This means for existing workloads they should > > not see any significant performance impact of this change. > > This is odd. Shouldn't an SCM_CGROUP cmsg be generated when the > receiver has SO_PASSCGROUP set and the sender passes SCM_CGROUP to > sendmsg? What would be the point ? Simo. -- 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/