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First off, I can't take credit for this other than the effort to try it out. This is a Dalvik VM optimized for our CPU, with JIT enabled. It was originally posted over at sdx-developers by developer "MeatCurtains"


Overall, the PDN feels faster after applying the fix, but I'll let the results speak for themselves:

stockquadrant 179
linpack 1.484
meatdvmquadrant 222
linpack 3.4

Even looking at Quadrant's more modest increase, and even that is a 25% bump.

Where I downloaded it from, someone was complaining it was crashy and unstable, however I've had no issues at all since installing it. If other people have the same experience we might want to consider it for being an "official" widely use hack.

How to install:

Download file to directory with adb.exe
adb remount (to mount system as read-write)
adb shell mv /system/lib/libdvm.so /system/lib/libdvm.so.pdn (backup stock version, highly recommended. DONT do this more than once, otherwise you'll overwrite your backup with the newer version)
adb push libdvm.so /system/lib/libdvm.so (push over the new one you downloaded)
adb shell rm -r /data/dalvik* (very important, we've installed a new dalvik VM, so MUST clear out dalvik cache)
adb shell reboot (reboot the device, and you're in business!) 1st boot will take a bit as the cache rebuilds

If for some reason you want to go back:

adb shell mv /system/lib/libdvm.so.pdn /system/lib/libdvm.so (restore backup version)
adb shell rm -r /data/dalvik* (very important, we've installed a new dalvik VM, so MUST clear out dalvik cache)
adb shell reboot (reboot the device)

Download link:http://www.mediafire.com/download.php?kzhhk99n53kiksh
 

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clockworx;27713]First off said:
http://www.mediafire.com/download.php?kzhhk99n53kiksh[/url]
Thanks clockworxI installed the libdvm.so and ran the benchmarks:linpack : normal res: 3.36 (but MFOPS number is always changig ranging from 3.32 - 5.85)Quadrant : 214Once again thanks !!
 

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Thanks yet again! I'm definitely going to test this out.EDIT: New numbers.....linpack : somewhere ~3.4 seems to be the average.Quadrant : 216These are definitely a bump up from the stock numbers.I did test video playback, which I was hoping would improve with this - no dice. I keep wondering if that problem lies with the AVC decoder in use, or maybe whatever driver is rendering video.
 

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Allow me to ask a trivial newbie question in the midst of an exciting development:[quote name='clockworx;27713] (backup stock version' date=' highly recommended. DONT do this more than once, otherwise you'll overwrite your backup with the newer version)[/QUOTE']Exactly how do we do a backup? (and backup which files?) I tried to search for "backup stock" but I couldn't find anything useful.Thanks for your patience. Now, back to normal programming...
 

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[quote name='hello-world;27753]Allow me to ask a trivial newbie question in the midst of an exciting [URL=development:Exactly]development:Exactly[/URL] how do we do a backup? (and backup which files?) I tried to search for "backup stock" but I couldn't find anything useful.Thanks for your patience. Now' date=' back to normal programming...[/QUOTE'] Follow the instructions in the first post. It has everything you need to back up the current lib file and install the new one.
 

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[quote name='hello-world;27753]Allow me to ask a trivial newbie question in the midst of an exciting [URL=development:Exactly]development:Exactly[/URL] how do we do a backup? (and backup which files?) I tried to search for "backup stock" but I couldn't find anything useful.Thanks for your patience. Now' date=' back to normal programming...[/QUOTE']This line, from the OP:adb shell mv /system/lib/libdvm.so /system/lib/libdvm.so.pdn This renames the original file to "libdvm.so.pdn", which becomes your backup file. As mentioned, you don't want to do that again after the change, or you'll overwrite your backup file!
 

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Thanks!To change the question a bit: would it make sense for me to backup this and other important directories to my PC,just in case? And if so, how would I do that? Thanks!
 

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Discussion Starter · #10 ·
[quote name='oozeeh;27877]What does this do?[/QUOTE] Oh' date=' you'll be sorry :)Here, read this:[url']http://en.wikipedia.org/wiki/Dalvik_(software[/url])Anyways, someone one the Samsung Developers forum did a version optimized for our architecture, and also adds Just-In-Time compilation.
 

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Discussion Starter · #11 ·
[quote name='oozeeh;27877]What does this do?[/QUOTE] Oh' date=' you'll be sorry :)Here, read this:[url']http://en.wikipedia.org/wiki/Dalvik_(software)[/url]So basically, it's a significant part of Android's brain. Anyways, someone one the Samsung Developers forum did a version optimized for our architecture, and also added Just-In-Time compilation.
 

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Discussion Starter · #13 ·
[quote name='hello-world;27783]Thanks!To change the question a bit: would it make sense for me to backup this and other important directories to my PC' date='just in case? And if so, how would I do that? Thanks![/QUOTE']It's relatively trivial to either:a) extract the files from system.img provided in Pandigital's update.zipb) Pull a backup from your working device.Either would work, but (
is probably easier for you at this point. If you have ADB working, do"adb pull /system <whatever_name_you_want_to_backup_to>"For example"adb pull /system PD_system_v7_24"will make a folder below wherever you run the command named "PD_system_v7_24", containing the directory structure of the system directory.
 

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Sorry for the noobishness, but how do I do the ADB remount you list as the first step? I thought I was doing it correctly, but I am getting fail messages saying 'read only' when I try further steps.
 

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Discussion Starter · #15 ·
same place as the move command. Do you get a response when you run "adb remount"?(This seems like a common issue where people's remount doesn't work, though I have no idea why)
 

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Okay, got the remount working just fine... very simple step that I really noobed up :pBut on this step: "adb shell rm -r /data/dalvik* (very important, we've installed a new dalvik VM, so MUST clear out dalvik cache)"I am getting a message: "...failed for /data/dalvik* No such file or directory", normal or not good?
 

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Discussion Starter · #17 ·
You may have deleted it before if you did all those commands. Try this:"adb shell ls /data/"You should get a list of directories. If dalvik-cache is there, try the rm command again:adb shell rm -r /data/dalvik*If it isn't there, then you should be fine.[quote name='bodex;28091]Okay' date=' got the remount working just fine... very simple step that I really noobed up :pBut on this step: "adb shell rm -r /data/dalvik* (very important, we've installed a new dalvik VM, so MUST clear out dalvik cache)"I am getting a message: "...failed for /data/dalvik* No such file or directory", normal or not good?[/QUOTE']
 

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Thanks Clockworx! Sometimes I make things harder than they actually are ;) Worked great though.Quadrant before, 175.. and after 231.Are the numbers people usually list for linpack the Mflops/s?
 

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this thread reminds me nostalgically of the entire history of the PDN on this forum... Those halcyon days... 5 weeks ago.
 
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