Re: [RFC][PATCH 8/8] PM / Sleep: Add user space interface for manipulating wakeup sources

From: Rafael J. Wysocki
Date: Fri Apr 27 2012 - 17:29:21 EST


On Friday, April 27, 2012, Arve Hjønnevåg wrote:
> 2012/4/27 Rafael J. Wysocki <rjw@xxxxxxx>:
> > On Friday, April 27, 2012, Arve Hjønnevåg wrote:
> >> 2012/4/26 Rafael J. Wysocki <rjw@xxxxxxx>:
> >> ...
> >> > ---
> >> > From: Rafael J. Wysocki <rjw@xxxxxxx>
> >> > Subject: PM / Sleep: Add user space interface for manipulating wakeup sources, v3
> >> >
> >> > Android allows user space to manipulate wakelocks using two
> >> > sysfs file located in /sys/power/, wake_lock and wake_unlock.
> >> > Writing a wakelock name and optionally a timeout to the wake_lock
> >> > file causes the wakelock whose name was written to be acquired (it
> >> > is created before is necessary), optionally with the given timeout.
> >> > Writing the name of a wakelock to wake_unlock causes that wakelock
> >> > to be released.
> >> >
> >> > Implement an analogous interface for user space using wakeup sources.
> >> > Add the /sys/power/wake_lock and /sys/power/wake_unlock files
> >> > allowing user space to create, activate and deactivate wakeup
> >> > sources, such that writing a name and optionally a timeout to
> >> > wake_lock causes the wakeup source of that name to be activated,
> >> > optionally with the given timeout. If that wakeup source doesn't
> >> > exist, it will be created and then activated. Writing a name to
> >> > wake_unlock causes the wakeup source of that name, if there is one,
> >> > to be deactivated. Wakeup sources created with the help of
> >> > wake_lock that haven't been used for more than 5 minutes are garbage
> >> > collected and destroyed. Moreover, there can be only WL_NUMBER_LIMIT
> >>
> >> I think it would be better if the garbage collection and limit was
> >> configurable and optional. I would probably turn both features off
> >> since I do not want to chase down bugs because a wakelock was ignored,
> >> and I think the garbage collection will erase stats that we care
> >> about.
> >
> > OK, but would you mind if I added the configurability as a separate incremental
> > patch?
> >
>
> That is fine with me.

Cool, thanks!
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