Re: suspend blockers & Android integration

From: Arve Hjønnevåg
Date: Mon Jun 07 2010 - 19:34:37 EST


2010/6/6 Thomas Gleixner <tglx@xxxxxxxxxxxxx>:
> On Sat, 5 Jun 2010, Arve Hjønnevåg wrote:
>> 2010/6/5 Thomas Gleixner <tglx@xxxxxxxxxxxxx>:
>> > On Sat, 5 Jun 2010, Arve Hjønnevåg wrote:
>> >> 2010/6/5 Thomas Gleixner <tglx@xxxxxxxxxxxxx>:
>> >> > On Sat, 5 Jun 2010, Arve Hjønnevåg wrote:
>> >> >> >> > That download might take a minute or two, but that's not an
>> >> >> >> > justification for the crapplication to run unconfined and prevent
>> >> >> >> > lower power states.
>> >> >> >> >
>> >> >> >>
>> >> >> >> I agree, but this is not a simple problem to solve.
>> >> >> >
>> >> >> > Not with suspend blockers, but with cgroup confinement of crap, it's
>> >> >> > straight forward.
>> >> >> >
>> >> >>
>> >> >> I don't think is is straight forward. If the a process in the frozen
>> >> >> group holds a resource that a process in the unfrozen group needs, how
>> >> >> do deal with that?
>> >> >
>> >> > I'm going to fix the framework which puts the group into freeze state
>> >> > w/o making sure that there is no held shared resource. Come on it's
>> >> > not rocket science.
>> >> >
>> >>
>> >> I'm not sure which framework you are talking about here, but I don't
>> >> think there is a single framework that knows about all shared
>> >> resources.
>> >
>> > Damn, it's not me talking about "our framework", you are mentioning
>> > when it fits your needs.
>>
>> You said you were going to fix the framework. I did know if you were
>> talking about the cgroup framework, or the android user-space
>> frameworks. I don't think either has knowledge about all shared
>> resources.
>
> The cgroup freezer makes sure that there are no in kernel resources
> blocked. Of course the user space side has to do the same and it's not
> rocket science.
>

It is much easier to make sure there are no kernel resources held than
that there are no resources held in user-space. The kernel threads
have to return to a safe location before they get frozen, where user
threads are just frozen wherever they are.

--
Arve Hjønnevåg
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/