From: Alan Cox on
> The power efficiency of a mobile device is depending on a sane overall
> software stack and not on the ability to mitigate crappy software in
> some obscure way which is prone to malfunction and disappoint users.

Even if you believe the kernel should be containing junk the model that
works and is used for everything else is resource management. Not giving
various tasks the ability to override rules, otherwise you end up needing
suspend blocker blockers next week.

A model based on the idea that a task can set its desired wakeup
behaviour *subject to hard limits* (ie soft/hard process wakeup) works
both for the sane system where its elegantly managing hard RT, and for
the crud where you sandbox it to stop it making a nasty mess.

Do we even need a syscall or will adding RLIMIT_WAKEUP or similar do the
trick ?

Alan
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From: Florian Mickler on
On Wed, 26 May 2010 19:02:04 +0100
Alan Cox <alan(a)lxorguk.ukuu.org.uk> wrote:

> > The power efficiency of a mobile device is depending on a sane overall
> > software stack and not on the ability to mitigate crappy software in
> > some obscure way which is prone to malfunction and disappoint users.
>
> Even if you believe the kernel should be containing junk the model that
> works and is used for everything else is resource management. Not giving
> various tasks the ability to override rules, otherwise you end up needing
> suspend blocker blockers next week.
>
> A model based on the idea that a task can set its desired wakeup
> behaviour *subject to hard limits* (ie soft/hard process wakeup) works
> both for the sane system where its elegantly managing hard RT, and for
> the crud where you sandbox it to stop it making a nasty mess.
>
> Do we even need a syscall or will adding RLIMIT_WAKEUP or similar do the
> trick ?
>
> Alan

Your approach definitely sounds better than the current solution.
What about mapping suspend blocker functionality later on, when this
interface exists, on to this new approach and deprecating it?

Cheers,
Flo
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From: Vitaly Wool on
On Thu, May 27, 2010 at 7:14 AM, Florian Mickler <florian(a)mickler.org> wrote:

> I'm not interested in "abusing processes". I just think, this is in
> limbo for too long already.
> Just decide something. One way or the other. The world will continue.

Oh man, you rule the world eh? :)

~Vitaly
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From: Vitaly Wool on
2010/5/27 Arve Hj�nnev�g <arve(a)android.com>:
> On Wed, May 26, 2010 at 6:16 AM, Alan Cox <alan(a)lxorguk.ukuu.org.uk> wrote:
>>> Really, what are you getting at? Do you deny that there are programs,
>>> that prevent a device from sleeping? (Just think of the bouncing
>>> cows app)
>>>
>>> And if you have two kernels, one with which your device is dead after 1
>>> hour and one with which your device is dead after 10 hours. Which would
>>> you prefer? I mean really... this is ridiculous.
>>
>> The problem you have is that this is policy. If I have the device wired
>> to a big screen and I want cows bouncing on it I'll be most upset if
>> instead it suspends.
>
> We never suspend when the screen is on. If the screen is off, I would
> not be upset if it suspends.

That's /wrong/. What if you have an active download ongoing when the
screen is off? This ugly simplistic approach is one of the worst
things in Android.

~Vitaly
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From: Arve Hjønnevåg on
2010/5/27 Vitaly Wool <vitalywool(a)gmail.com>:
> 2010/5/27 Arve Hj�nnev�g <arve(a)android.com>:
>> On Wed, May 26, 2010 at 6:16 AM, Alan Cox <alan(a)lxorguk.ukuu.org.uk> wrote:
>>>> Really, what are you getting at? Do you deny that there are programs,
>>>> that prevent a device from sleeping? (Just think of the bouncing
>>>> cows app)
>>>>
>>>> And if you have two kernels, one with which your device is dead after 1
>>>> hour and one with which your device is dead after 10 hours. Which would
>>>> you prefer? I mean really... this is ridiculous.
>>>
>>> The problem you have is that this is policy. If I have the device wired
>>> to a big screen and I want cows bouncing on it I'll be most upset if
>>> instead it suspends.
>>
>> We never suspend when the screen is on. If the screen is off, I would
>> not be upset if it suspends.
>
> That's /wrong/. What if you have an active download ongoing when the
> screen is off? This ugly simplistic approach is one of the worst
> things in Android.

On android we have code that blocks suspend while downloading. On
non-android systems I have used if the download has not finished by
the time the auto-sleep timeout kicks in, the system will suspend and
the download halts.

--
Arve Hj�nnev�g
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