From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexei Starovoitov Subject: Re: [RFC PATCH 3/5] bpf: add BPF_PROG_ATTACH and BPF_PROG_DETACH commands Date: Wed, 17 Aug 2016 10:48:14 -0700 Message-ID: <20160817174813.GA98226@ast-mbp.thefacebook.com> References: <1471442448-1248-1-git-send-email-daniel@zonque.org> <1471442448-1248-4-git-send-email-daniel@zonque.org> <20160817142047.GB4021@htj.duckdns.org> <95e8b773-416f-72cc-4045-dd10d94e6484@zonque.org> <20160817150646.GB6299@htj.duckdns.org> <7e607709-eca0-2ab6-2379-99cec519d859@zonque.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Tejun Heo , daniel@iogearbox.net, ast@fb.com, davem@davemloft.net, kafai@fb.com, fw@strlen.de, pablo@netfilter.org, harald@redhat.com, netdev@vger.kernel.org To: Daniel Mack Return-path: Received: from mail-pf0-f196.google.com ([209.85.192.196]:33756 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753023AbcHQRsV (ORCPT ); Wed, 17 Aug 2016 13:48:21 -0400 Received: by mail-pf0-f196.google.com with SMTP id i6so8489588pfe.0 for ; Wed, 17 Aug 2016 10:48:21 -0700 (PDT) Content-Disposition: inline In-Reply-To: <7e607709-eca0-2ab6-2379-99cec519d859@zonque.org> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Aug 17, 2016 at 05:51:44PM +0200, Daniel Mack wrote: > On 08/17/2016 05:06 PM, Tejun Heo wrote: > > What I'd suggest is keeping two sets of pointers, one set for the > > programs explicitly attached to the cgroup and the other for programs > > which are to be executed for the cgroup. The two pointers in the > > latter set will point to the closest non-null program in its ancestry. > > Note that the pointers may point to programs belonging to different > > ancestors. > > > > A - B - C > > \ D - E > > > > Let's say B has both ingress and egress programs and D only has > > egress. E's execution pointers should point to D's egress program and > > B's ingress program. > > > > The pointers would need to be updated > > > > 1. When a program is installed or removed. For simplicity's sake, we > > can just walk the whole hierarchy. If that's too expensive > > (shouldn't be), we can find out the closest ancestor where both > > programs can be determined and then walk from there. > > > > 2. When a new cgroup is created, it should inherit its execution table > > from its parent. > > Ok, yes, that sounds sane to me. Will implement that scheme. That makes sense to me as well. Sounds quite flexible and fast with only one check per packet per direction.