Messages in this thread | | | Date | Mon, 31 Oct 2022 14:11:40 +0100 | From | Michal Koutný <> | Subject | Re: [PATCH] cgroup: Simplify code in css_set_move_task |
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Hello.
> 1) If calls 'css_set_update_populated' , the cset is either getting the > first task or losing the last. There is a need to update the populated > state of the cset only when 'css_set_populated' returns false. > In other words, the last has been deleted from from_cset and the first > hasn't been added to to_cset yet.
I've likely misread the condition previously. I see how this works now (update happens after "from_cset" but before "to_cset" migration).
> 3) In order to update the populated state of to_cset the same way > from_cset does, 'css_set_update_populated' is also invoked during the > process of moving a task to to_cset.
As I think more about this in the context of vertical migrations (ancestor<->descendant, such as during controller dis- or enablement), I'm afraid the inverted order would lead to "spurious" emptiness notifications in ancestors (in the case a there is just a single task that migrates parent->child, parent/cgroup.populated would generate and event that'd be nullified by the subsequent population of the child).
So I'm not sure the change is worth it.
Michal [unhandled content-type:application/pgp-signature] | |