Enabling JIT compiler on Android 2.1 for Odroid

References:
http://www.uglyn.com:8080/showItem/showDetail/9007534.html
http://androidforums.com/droid-all-things-root/51027-how-enable-jit.html
http://github.com/CyanogenMod/android_bionic/tree/froyo/linker

Descriptions:

Start from ODROID source code (hk_eclair_2.1_r2.tar.gz).
Make buildspec.mk and build as the following.

Code:

$ cd hk_eclair_2.1_r2
$ echo "WITH_JIT:=true" > buildspec.mk
$ hkdkc100_build.sh

Copy following files to PC (or adb connected computer)

Code:

./out/target/product/hkdkc100/system/bin/dalvikvm
./out/target/product/hkdkc100/system/lib/libdvm.so
./out/target/product/hkdkc100/system/lib/libnativeheler.so

On PC,

Code:

> adb pull /system/build.prop build.prop

Edit build.prop
Add the following line into the last line in build.prop.

Code:

dalvik.vm.execution-mode=int:jit

Save

Code:

> adb push build.prop /system/build.prop
> adb push dalvikvm /system/bin/dalvikvm
> adb push libdvm.so /system/lib/libdvm.so
> adb push libnativeheler.so /system/lib/libnativeheler.so
> adb shell chmod 755 /system/bin/dalvikvm
> adb shell dalvikvm -h

You can see "with_jit" option in last part of displayed.
Reboot


Test Result:
I tested with "linpack for android".
On JIT disabled ODROID, it got about 15secs.
On JIT enabled ODROID, it got about 10secs.
The result says that JIT enabled odroid runs 50% faster.


To turn off JIT:
change build.prop to

Code:

dalvik.vm.execution-mode=int:fast

Hi,

As I can taste it, but look good

Thanks,

Alvaro

Hi,

My results were:



ODROID(5-8-2010) without JIT = 5.651 Mflops/s
ODROID(5-8-2010) with JIT = 8.538 Mflops/s

There is an improvement of 51.08%

This coupled with EXT4, you get a much faster

Attached files obtained from the compilation of the system, so you will soon on getting JIT

Thanks,

Alvaro

Seeing the improvement, could you get a official ROM with JIT?

What is the improvement of ext4?

Hi David,

The information on EXT4 be found at: http://odroid.foros-phpbb.com/odroid-discussion-f1/odroid-release-2010_08_05-t260.htm

Alvaro wrote:

odroid wrote:Here are simple process to adopt the EXT4 file system for testing.

1. Change kernel option to support EXT4 file system and compile it and put it to Odroid.
2. Back up files in Micro-SD card.
3. Format Micro-SD card's two partitions with EXT4 not EXT3.
4. Restore back up files.
5. Change bootargs of uboot from EXT3 to EXT4.

Please try this process and get back to me.
When I have some time, I'll also try this.

Hi odroid,

The results were:

Charging time, EXT3 version (08/05/2010): 55 ~ 60 seconds, depending on battery level.

Loading time EXT4 version (apart from the code posted 22/03/2010): 35 ~ 45 seconds, depending on battery level.

But I fear that to me is not valid because the current version I can not connect to my network and also the current is more stable. But if it had that hit, no doubt I was with EXT4

Thanks,

Alvaro

Thanks,

Alvaro