Performance Boost: Enabling Dalvik's JIT compiler and increasing heap size<- Read :)

helf · 02-20-2014, 10:16 PM

Hey, I forgot you can't change the titles of a post after the initial posting. So I am posting the bit about the Dalvik VM JIT I just noticed on my PE as well as heap size so more people see it.

Some light reading on Dalvik's JIT compiler.
http://android-developers.blogspot.c...alvik-jit.html

Android 2.2 added a JIT (Just-In-Time) compiler to the Dalvik VM. Dalvik is the interpreter that is the heart of Android and runs all your apps. (It is being superseded by ART in latest Android releases)

I was digging around in my build.prop looking for more stuff to do to my PE to try and get as much performance as I could out of the poor old thing when I noticed the Dalvik execution mode line. I did some googling and read up on Dalvik some and decided to try changing it to the JIT instead of the default failsafe "fast" mode. My Linpack results went from 3.1-3.2 MFLOPS average to 5.1-5.2MFLOPS which is a pretty drastic
increase.

The other thing I changed in my build.prop was the Dalvik heap size.I doubled the default heap size to 256MB from 128MB that is the default. The Dalvik heap size adjusts how much memory a Dalvik VM instance can use. The more memory a single app can use, the less often Dalvik has to run through its garbage collection routines. This takes a load off the CPU and may be one reason my PE has seemed so much snappier. This may just be placebo, though. It shouldn't cause any harm and the PE has 512MB of RAM to play with so... worth doing, imo.

Code:

dalvik.vm.heapsize=256M
dalvik.vm.execution-mode=init:jit

I have had my PE running with a 256MB heap for 2 years with no issues and a few days with the JIT on and no problems. I made the same changes to my friends PE today and he hasn't had any problems, either.

solarbanjo · 03-08-2014, 08:04 PM

And this is exactly why I keep following this forum. Great tip, helf! I just keep finding reasons to love my little Edge...

helf · 03-18-2014, 12:29 AM

np! I'm glad people are still checking in. Post your experiences with the VM change, if you want. I'm curious to see how other people fair with it.

Gerrye · 04-09-2014, 09:45 AM

Quote:

Originally Posted by helf

Hey, I forgot you can't change the titles of a post after the initial posting. So I am posting the bit about the Dalvik VM JIT I just noticed on my PE as well as heap size so more people see it.

Some light reading on Dalvik's JIT compiler.
http://android-developers.blogspot.c...alvik-jit.html

Android 2.2 added a JIT (Just-In-Time) compiler to the Dalvik VM. Dalvik is the interpreter that is the heart of Android and runs all your apps. (It is being superseded by ART in latest Android releases)

I was digging around in my build.prop looking for more stuff to do to my PE to try and get as much performance as I could out of the poor old thing when I noticed the Dalvik execution mode line. I did some googling and read up on Dalvik some and decided to try changing it to the JIT instead of the default failsafe "fast" mode. My Linpack results went from 3.1-3.2 MFLOPS average to 5.1-5.2MFLOPS which is a pretty drastic
increase.

The other thing I changed in my build.prop was the Dalvik heap size.I doubled the default heap size to 256MB from 128MB that is the default. The Dalvik heap size adjusts how much memory a Dalvik VM instance can use. The more memory a single app can use, the less often Dalvik has to run through its garbage collection routines. This takes a load off the CPU and may be one reason my PE has seemed so much snappier. This may just be placebo, though. It shouldn't cause any harm and the PE has 512MB of RAM to play with so... worth doing, imo.

Code:

dalvik.vm.heapsize=256M
dalvik.vm.execution-mode=init:jit

I have had my PE running with a 256MB heap for 2 years with no issues and a few days with the JIT on and no problems. I made the same changes to my friends PE today and he hasn't had any problems, either.

It might be helpful if those of you who put up articles about changing files like build.prop, go through the steps of how to change build.prop for those fellow travelers who would like to benefit from these improvements but are a little bit nervous about how to actually implement them without turning their beloved PEs into the dreaded "brick"

Thanks, in advance...

mjc1 · 09-25-2014, 09:09 PM

I'm a noob, so I have no idea how to do this. Can you or anyone else explain how this is done?Thank you.

Quote:

Originally Posted by helf

Hey, I forgot you can't change the titles of a post after the initial posting. So I am posting the bit about the Dalvik VM JIT I just noticed on my PE as well as heap size so more people see it.

Some light reading on Dalvik's JIT compiler.
http://android-developers.blogspot.c...alvik-jit.html

Android 2.2 added a JIT (Just-In-Time) compiler to the Dalvik VM. Dalvik is the interpreter that is the heart of Android and runs all your apps. (It is being superseded by ART in latest Android releases)

I was digging around in my build.prop looking for more stuff to do to my PE to try and get as much performance as I could out of the poor old thing when I noticed the Dalvik execution mode line. I did some googling and read up on Dalvik some and decided to try changing it to the JIT instead of the default failsafe "fast" mode. My Linpack results went from 3.1-3.2 MFLOPS average to 5.1-5.2MFLOPS which is a pretty drastic
increase.

The other thing I changed in my build.prop was the Dalvik heap size.I doubled the default heap size to 256MB from 128MB that is the default. The Dalvik heap size adjusts how much memory a Dalvik VM instance can use. The more memory a single app can use, the less often Dalvik has to run through its garbage collection routines. This takes a load off the CPU and may be one reason my PE has seemed so much snappier. This may just be placebo, though. It shouldn't cause any harm and the PE has 512MB of RAM to play with so... worth doing, imo.

Code:

dalvik.vm.heapsize=256M
dalvik.vm.execution-mode=init:jit

I have had my PE running with a 256MB heap for 2 years with no issues and a few days with the JIT on and no problems. I made the same changes to my friends PE today and he hasn't had any problems, either.

helf · 10-16-2014, 09:27 AM

Quote:

Originally Posted by mjc1

I'm a noob, so I have no idea how to do this. Can you or anyone else explain how this is done?Thank you.

Hi, mjc. I will try and post an easy to follow step-by-step soon. I've been busy and failed to check on the forum. Sorry for the really delayed response. If you are still interested in doing this you can send me a private message and I can try helping quicker, as well.

janhall_us · 10-18-2014, 03:10 PM

Please don't take this discussion private... there are others that are lurking but interested too

helf · 10-20-2014, 09:13 AM

Ha. I wont. Couldn't get to it this weekend. Gonna try over the next few nights. I need to update my eDGe anyways.

Since the mods appear super anal about image sizes and number of images, I will probably make a PDF and just post a link to it.

02-20-2014, 10:16 PM	#1
helf Zealot Posts: 124 Karma: 500250 Join Date: Jun 2011 Device: Entourage Pocket eDGe, Entourage eDGe, Samsung Galaxy Note II	Performance Boost: Enabling Dalvik's JIT compiler and increasing heap size<- Read :) Hey, I forgot you can't change the titles of a post after the initial posting. So I am posting the bit about the Dalvik VM JIT I just noticed on my PE as well as heap size so more people see it. Some light reading on Dalvik's JIT compiler. http://android-developers.blogspot.c...alvik-jit.html Android 2.2 added a JIT (Just-In-Time) compiler to the Dalvik VM. Dalvik is the interpreter that is the heart of Android and runs all your apps. (It is being superseded by ART in latest Android releases) I was digging around in my build.prop looking for more stuff to do to my PE to try and get as much performance as I could out of the poor old thing when I noticed the Dalvik execution mode line. I did some googling and read up on Dalvik some and decided to try changing it to the JIT instead of the default failsafe "fast" mode. My Linpack results went from 3.1-3.2 MFLOPS average to 5.1-5.2MFLOPS which is a pretty drastic increase. The other thing I changed in my build.prop was the Dalvik heap size.I doubled the default heap size to 256MB from 128MB that is the default. The Dalvik heap size adjusts how much memory a Dalvik VM instance can use. The more memory a single app can use, the less often Dalvik has to run through its garbage collection routines. This takes a load off the CPU and may be one reason my PE has seemed so much snappier. This may just be placebo, though. It shouldn't cause any harm and the PE has 512MB of RAM to play with so... worth doing, imo. Code: dalvik.vm.heapsize=256M dalvik.vm.execution-mode=init:jit I have had my PE running with a 256MB heap for 2 years with no issues and a few days with the JIT on and no problems. I made the same changes to my friends PE today and he hasn't had any problems, either.

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03-08-2014, 08:04 PM	#2
solarbanjo Enthusiast Posts: 25 Karma: 582 Join Date: Jul 2011 Device: Entourage Pocket Edge, Entourage Edge	And this is exactly why I keep following this forum. Great tip, helf! I just keep finding reasons to love my little Edge...

03-18-2014, 12:29 AM	#3
helf Zealot Posts: 124 Karma: 500250 Join Date: Jun 2011 Device: Entourage Pocket eDGe, Entourage eDGe, Samsung Galaxy Note II	np! I'm glad people are still checking in. Post your experiences with the VM change, if you want. I'm curious to see how other people fair with it.

10-18-2014, 03:10 PM	#7
janhall_us Enthusiast Posts: 29 Karma: 22360 Join Date: May 2009 Device: Kindle2, Pocket eDGe, (full-size) eDGe, Nexus 7, Galaxy Note 10.1	Please don't take this discussion private... there are others that are lurking but interested too

10-20-2014, 09:13 AM	#8
helf Zealot Posts: 124 Karma: 500250 Join Date: Jun 2011 Device: Entourage Pocket eDGe, Entourage eDGe, Samsung Galaxy Note II	Ha. I wont. Couldn't get to it this weekend. Gonna try over the next few nights. I need to update my eDGe anyways. Since the mods appear super anal about image sizes and number of images, I will probably make a PDF and just post a link to it.

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