From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752340AbcFWWKm (ORCPT ); Thu, 23 Jun 2016 18:10:42 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:54753 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751189AbcFWWKk (ORCPT ); Thu, 23 Jun 2016 18:10:40 -0400 Date: Thu, 23 Jun 2016 15:10:15 -0700 From: Martin KaFai Lau To: Daniel Borkmann CC: , , , Alexei Starovoitov , Tejun Heo , Subject: Re: [PATCH net-next v2 2/4] cgroup: bpf: Add BPF_MAP_TYPE_CGROUP_ARRAY Message-ID: <20160623221015.GA93293@kafai-mba.DHCP.thefacebook.com> References: <1466630252-3822277-1-git-send-email-kafai@fb.com> <1466630252-3822277-3-git-send-email-kafai@fb.com> <576BAF07.4020302@iogearbox.net> <20160623212616.GA90834@kafai-mba.DHCP.thefacebook.com> <576C5990.9000300@iogearbox.net> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <576C5990.9000300@iogearbox.net> User-Agent: Mutt/1.5.23.1 (2014-03-12) X-Originating-IP: [192.168.52.123] X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-06-23_10:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 23, 2016 at 11:50:08PM +0200, Daniel Borkmann wrote: > On 06/23/2016 11:26 PM, Martin KaFai Lau wrote: > >We are still hatching out how to set this up in production. However, the > >situation is similar to removing the pinned file. s/pinned file/pinned cgroup-array/ > I presume you mean removing the last BPF program holding a reference on > the cgroup array map. Yes > (Any user space visibility like struct files given > from the anon inode and pinnings are tracked via uref, btw, which is > needed to break possible complex dependencies among tail called programs.) Yep. Understood on prog_array use case. Thanks, -- Martin