Re: suspend blockers & Android integration

From: Ingo Molnar
Date: Fri Jun 04 2010 - 02:23:14 EST



* Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:

> [...]
>
> And those two things go together. The /sys/power/state thing is a global
> suspend - which I don't think is appropriate for a opportunistic thing in
> the first place, especially for multi-core.
>
> A well-designed opportunistic suspend should be a two-phase thing: an
> opportunistc CPU hotunplug (shutting down cores one by one as the system is
> idle), and not a "global" event in the first place. And only when you've
> reached single-core state should you then say "do I suspend the system too".

Shutting a core down would be a natural idle level, and when the last one goes
idle we can do the suspend. (it happens as part of suspend anyway)

So on systems that dont want to auto-suspend this would indeed behave like you
suggest: the final core left would run as UP in essence.

Ingo
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