Re: Async suspend-resume patch w/ completions (was: Re: Async suspend-resume patch w/ rwsems)

Alan Stern
2009-12-20T17:12:09Z

On Sun, 20 Dec 2009, Rafael J. Wysocki wrote:

> > It's too early to come to this sort of conclusion (i.e., that suspend
> > and resume react very differently to an asynchronous approach). Unless
> > you have some definite _reason_ for thinking that resume will benefit
> > more than suspend, you shouldn't try to generalize so much from tests
> > on only two systems.
>
> In fact I have one reason. Namely, the things that drivers do on suspend and
> resume are evidently quite different and on these two systems I was able to
> test they apparently took different amounts of time to complete.
>
> The very fact that on both systems resume is substantially longer than suspend,
> even if all devices are suspended and resumed synchronously, is quite
> interesting.

Yes, it is. But it doesn't mean that suspend won't benefit from
asynchronicity; it just means that the benefits might not be as large
as they are for resume.

Alan Stern