Running apps while framework is down on kindle PW, for better performance

[Aeris]

Hi there, I've a question.

Is there a way to run apps after setting the framework down on Kindle Paperwhite? It would be really useful to free memory with heavy apps, and the workframe could be still set on after closing the program.

I know that it was possible on kindle 3: with KindlePdfViewer for example you had just to stop the framework with:

/etc/init.d/framework stop

Then run the software, enjoy outstanding performance and executing "/etc/init.d/framework start" after it closes.

I've tried to achieve this for example with koreader, using the command:

stop framework

The problem is that after executing this, everything stops and can get through the rest of the code and make other apps launch, as I did instead on Kindle 3.
I've tried also with /etc/upstart/framework stop, but didn't work.

So I wonder if running apps while framework is down is still possible with kindle PW devices. It would be really important to me, because PW has still 256 Mbyte of RAM like kindle 3, but a really heavier firmware that waste all of this memory, so apps like Koreader continue to crash.

Thank you in advance

[twobob]

The issue is really that this device works on an X.

the touchscreen is serviced by it.
as is the Xdamage code (decides what to redraw on the screen) squirrelled away in the LUA.

it's this 2nd point that is the issue really, the first one I could help with by simply providing a tinier X, with the relevant config for the Touchscreen.

I have actually done some research on hi-jacking the xdamage code however it is Amazon proprietary code so that limits how we can use it in a few ways.

Posting stuff about it on here for example can not contain code excerpts etc etc.

but yeah, that is the issue and yep I have tried to work around it before.
DOUBTLESS it can be done. Haven't had time to properly have a dig into it yet.

Too much too do, not enough time, not enough people digging...

When you say "crash" do you mean restart the X? or what?
IIRC there is a hardcoded "reset X cos we are low on memory" value that maybe could be adjusted...

Need more info on exactly what you are trying to fix.

[Aeris]

Here there is the bug-thread I've opened on github (with a bugmenot account cuz lazy xD):

https://github.com/koreader/koreader/issues/285

Yes, it restarts the framework due to low memory, to avoid crashing itself. The framework now is so heavy, if only it could be shut off while keeping X on... maybe would be useful also to execute debian and other distro flawlessly.

It's quite a shame to have a Kindle PW with a double frequency CPU respect to Kindle 3, but that runs slower due to insufficient RAM...

[twobob]

hmmmmmm

thinking

[NiLuJe]

stop lab126_gui stops the UI, and still leaves X running (which you'd stop by, you guessed it stop x).

If you kill x, start x restarts everything. If you don't, start lab126_gui.

(Why lab126_gui and not framework? Because it's a meta event, and handles a bunch of other things more neatly (the progress bar, among other things)).

You will have to trap SIGTERM if this is used in a KUAL script, because stopping the framework propagates a SIGTERM to everything the framework launched (meaning KUAL & the script it ran). Check the ScreenSavers/Fonts KUAL extension for examples of how I did it for X or the framework (because busybox's trap implementation is finicky, and so is upstart, so you can potentially confuse upstart by doing it wrong).

[Aeris]

I put stop lab126_gui in the koreader script, before launching ./reader.lua, but the screen became all black and koreader didn't appear later

Sorry but I'm a newbie and not sure to get all what you mean... by "trapping", as you say, the SIGTERM, can I start Koreader while taking off the framework?

[Aeris]

I did:

trap "" SIGTERM
stop framework

And, after closing the app

start framework

What to say, it's great!

[twobob]

I kind of recall the upper mem cap being somewhere in upstart but it's been a long time since I fiddled in there... Sorry...

EDIT: And I am not certain it is in there... but I am certain I have seen the setting "somewhere".

[knc1]

Originally Posted by twobob

I kind of recall the upper mem cap being somewhere in upstart but it's been a long time since I fiddled in there... Sorry...

EDIT: And I am not certain it is in there... but I am certain I have seen the setting "somewhere".

It is in the kdb database, which is in a read-only cramfs filesystem.

Some off-the-wall file name, like kdb.src or something.
I posted about it somewhere recently.

[twobob]

ah cool. Easy enough to amend and build another one then.

Good info! (might end up doing that myself)