From cd7f4c49582853fa74d3cb9f5bbd8722c03e2a99 Mon Sep 17 00:00:00 2001 From: Michael Kerrisk Date: Thu, 11 Jan 2018 00:52:26 +0100 Subject: [PATCH] cgroups.7: Add a detail on delegation of cgroup.threads Some notes from a conversation with Tejun Heo: Subject: Re: cgroups(7): documenting cgroups v2 delegation Date: Wed, 10 Jan 2018 14:27:26 -0800 From: Tejun Heo > > 1. When delegating, cgroup.threads should be delegated. Doing that > > selectively doesn't achieve anything meaningful. > > Understood. But surely delegating cgroup.threads is effectively > meaningless when delegating a "domain" cgroup tree? (Obviously it's > not harmful to delegate the the cgroup.threads file in this case; > it's just not useful to do so.) Yeap, unless we can somehow support non-root mixed domains. Signed-off-by: Michael Kerrisk --- man7/cgroups.7 | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/man7/cgroups.7 b/man7/cgroups.7 index c07160a09..1d7edd6e5 100644 --- a/man7/cgroups.7 +++ b/man7/cgroups.7 @@ -915,6 +915,12 @@ the delegater might instead add selected controllers to this file.) Changing the ownership of this file is necessary if a threaded subtree is being delegated (see the description of "thread mode", below). This permits the delegatee to write thread IDs to the file. +(The ownership of this file can also be changed when delegating +a domain subtree, but currently this serves no purpose, +since, as described below, it is not possible to move a thread between +domain cgroups by writing its thread ID to the +.IR cgroup.tasks +file.) .PP The delegater should .I not