Messages in this thread | | | Date | Tue, 15 Dec 2009 07:26:41 -0800 (PST) | From | Linus Torvalds <> | Subject | Re: Async suspend-resume patch w/ completions (was: Re: Async suspend-resume patch w/ rwsems) |
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On Tue, 15 Dec 2009, Rafael J. Wysocki wrote: > > > > Give a real example that matters. > > I'll try. Let -> denote child-parent relationships and assume dpm_list looks > like this:
No.
I mean something real - something like
- if you run on a non-PC with two USB buses behind non-PCI controllers.
- device xyz.
> If this applies to _resume_ only, then I agree, but the Arjan's data clearly > show that serio devices take much more time to suspend than USB.
I mean in general - something where you actually have hard data that some device really needs anythign more than my one-liner, and really _needs_ some complex infrastructure.
Not "let's imagine a case like xyz".
> But if we only talk about resume, the PCI bridges don't really matter, > because they are resumed before all devices that depend on them, so they don't > really need to wait for anyone anyway.
But that's my _point_. That's the whole point of the one-liner patch. Read the comment above that one-liner.
My whole point was that by doing the whole "wait for children" in generic code, you also made devices - such as PCI bridges - have to wait for children, even though they don't need to, and don't want to.
So I suggested an admittedly ugly hack to take care of it - rather than some complex infrastructure.
Linus
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