Hello, On Wed, Aug 03, 2022 at 03:22:16PM -0400, Johannes Weiner wrote: > Where it gets trickier is also stopping the tracking of task counts in > a cgroup. For re-enabling afterwards, we'd have to freeze scheduler > and cgroup state and find all tasks of interest across all CPUs for > the given cgroup to recreate the counts. I'm not quite sure whether > that's feasible, and if so, whether it's worth the savings. If this turns out to be necessary, I wonder whether we can just be opportunistic. ie. don't bother with walking all the tasks but only remember whether a task is accounted at a given level or not (this can be a bitmap which is allocated at cgroup attach type and in most caess will be pretty small). Then, maybe we can just start accounting them as they cycle through state transitions - we ignore the ones leaving states that they weren't accounted for and start remembering the new states they enter. Thanks. -- tejun
