Re: [PATCH 1/8] PM: Opportunistic suspend support.

James Bottomley
2010-05-26T18:10:05Z

On Wed, 2010-05-26 at 19:42 +0200, Pavel Machek wrote:
> Hi!
>
> > > > > The main and most important one being that suspend is a global property
> > > > > and can/will hurt sensible tasks. It puts the whole task model upside
> > > > > down.
> > > >
> > > > OK, so I believe you have an android phone ... it already implements
> > > > this model ... specifically what are the problems on that platform this
> > > > causes?
> > >
> > > I do not have one, nor have I ever written an application for it (nor
> > > will I likely ever do that, since I detest Java), but I would expect an
> > > application to run when its runnable.
> >
> > OK, so I've got one ... tell me what I should see and I'll try to
> > reproduce.
>
> Umm... try to boot ordinary distro and see how it copes with
> opportunistic suspend?

That's not really going to help, is it? The issue I was curious are
what are the bad things that result from interfering with the regular
scheduling of processes ... because undeniably suspend (whether
opportunistic or ordinary) does produce this interference.

I could boot debian on an android and have it suspend ... that's still
not going to answer my question.

> I do have android here, and of course it work well with custom
> userland. Question is: can common distro be reasonably modified to
> work with suspend blockers, in a way that's backward compatible?

You mean how an app could run if it was compiled with suspend blockers
but the platform doesn't support it? That's a simple runtime switch in
the library surely?

James