From mboxrd@z Thu Jan  1 00:00:00 1970
From: Daniel Mack <daniel@zonque.org>
Subject: Re: [RFC PATCH 3/5] bpf: add BPF_PROG_ATTACH and BPF_PROG_DETACH
 commands
Date: Wed, 17 Aug 2016 17:51:44 +0200
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To: Tejun Heo <htejun@fb.com>
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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.


Thanks!
Daniel