Messages in this thread | | | Date | Wed, 7 Apr 2021 20:39:40 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 0/9] sched: Core scheduling interfaces |
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On Tue, Apr 06, 2021 at 12:08:50PM -0400, Tejun Heo wrote:
> I see. Yeah, if we really need it, I'm not sure it fits in cgroup interface > proper. As I wrote elsewhere, these things are usually implemented on the > originating subsystem interface with cgroup ID as a parameter.
This would be something like:
prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_FROM, cgroup-fd, PIDTYPE_CGROUP, NULL);
right? Where we assign to self the cookie from the cgroup.
The problem I see with this is that a task can trivially undo/circumvent this by calling PR_SCHED_CORE_CLEAR on itself, at which point it can share with system tasks again.
Also, it doesn't really transfer well to the group/tasks thing. When a task joins a cgroup, it doesn't automagically gain the cgroup properties. Whoever does the transition will then also have to prctl() this, which nobody will do.
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