Difference between Android and Linux Kernel ?

[Sangili Pandian Chelliah]

I know Android uses the Linux kernel. I hope the Android developers did some modification with original Linux Kernel, especially in standard C libraries. My question is whether the processing speed of Linux and Android kernel are the same or different. I did some tests in different OS like windows and Redhat Linux and unbuntu and android. By the results Android is very slow. Android uses same Linux kernel... why this process variations but i know we cant expect same speed as in Linux, but I had huge differences (for example: Windows take 11 sec, Linux takes 4 sec, but Android takes 55 sec to complete my test) So What is the reason for this speed variation between these two linux kernels (Android and redhat both are 2.6)?

I'm using Android Kernel version  3.2.0.

Thanks and Regards,

Sangili Pandian C

[Avtar Singh]

I know Android uses the Linux kernel. I hope the Android developers did some modification with original Linux Kernel, especially in standard C libraries. My question is whether the processing speed of Linux and Android kernel are the same or different. I did some tests in different OS like windows and Redhat Linux and unbuntu and android. By the results Android is very slow. Android uses same Linux kernel... why this process variations but i know we cant expect same speed as in Linux, but I had huge differences (for example: Windows take 11 sec, Linux takes 4 sec, but Android takes 55 sec to complete my test) So What is the reason for this speed variation between these two linux kernels (Android and redhat both are 2.6)?

I'm using Android Kernel version  3.2.0.

The Linux Kernel in Android has several patches/modifications. I have a hunch that your test environments are not equivalent. You need to provide more data for somebody here to help you:

• What specific thing are you measuring?
• Test environment- Its setup, measuring mechanism and post-measure analysis mechanism.

- Avtar

[Sangili Pandian Chelliah]

Thanks for quick reply ,

                  Actually we making Bio-Metric devices using Android Platform. There I've been using a algorithm for matching the templates. Here i have facing big challenge. 

                  In case of Linux (RedHat, Ubuntu) this algorithm gives milliseconds to compare 100 templates.

And also in Windows 3 seconds. But in Android it leads 30 seconds. It's huge different right. 

                 My biggest doubt is Why this huge different even though using same Linux kernel. 

My Platform Specification:

          1. ARM cortex A8 processor with 750 GHZ.

          2. Beagle Bone  is the developing kit. 

    

          3. That algorithm has fulfill ISO standards. 

[Avtar Singh]

                  Actually we making Bio-Metric devices using Android Platform. There I've been using a algorithm for matching the templates. Here i have facing big challenge. 

                  In case of Linux (RedHat, Ubuntu) this algorithm gives milliseconds to compare 100 templates.

And also in Windows 3 seconds. But in Android it leads 30 seconds. It's huge different right. 

Do you mean to say that Windows/RedHat/Ubuntu/Android were running on ARM cortex A8 with 750GHz? Not quite so, right? If not, what is the corresponding hardware on which others are running. 

 

                 My biggest doubt is Why this huge different even though using same Linux kernel. 

Kernel alone cannot be held responsible for slow performance.

[Sangili Pandian Chelliah]

 Sorry i had spell mistakes on my previous post. That is 750 MHz not GHz. Android alone running in the ARM core , others are running an Intel core with 2 GHz. But compare with MIPS rate both do not make big different know.  

[David Ahern]

On 10/19/12 12:41 AM, Sangili Pandian Chelliah wrote:
> Thanks for quick reply ,
>
>
> Actually we making Bio-Metric devices using Android
> Platform. There I've been using a algorithm for matching the templates.
> Here i have facing big challenge.
>
> In case of Linux (RedHat, Ubuntu) this algorithm
> gives milliseconds to compare 100 templates.
> And also in Windows 3 seconds. But in Android it leads 30 seconds. It's
> huge different right.
>
> My biggest doubt is Why this huge different even
> though using same Linux kernel.

Have you tried using the perf tool (Peformance Events)? A number of
patches have been committed lately to get it working on Android.
Checkout the perf/core branch in Arnaldo's git repository:

git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

I suggest looking at scheduling events as well as profiling.

David

[Sangili Pandian Chelliah]

Thanks for your reply david,

                 I couldn't find the page of you mentioned link. I think its not alive. Where i can download the perf tool? 

[David Ahern]

On 10/20/12 2:20 AM, Sangili Pandian Chelliah wrote:
> Thanks for your reply david,
>
> I couldn't find the page of you mentioned link. I
> think its not alive. Where i can download the perf tool?

e.g.,
mkdir perf.git
cd perf.git

git init
git add remote acme git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux
git remote update

git checkout remotes/acme/perf/core
cd tools/perf

look at Documentation/android.txt

David

[Valeri Atamaniouk]

Have you tried to compare with Ubuntu on ARM? https://wiki.ubuntu.com/ARM/OMAP
It has pretty much original kernal.

-valeri

[Sangili Pandian Chelliah]

 Thanks for the reply Valeri,

          Have you tried to compare with Ubuntu on ARM? https://wiki.ubuntu.com/ARM/OMAP
It has pretty much original kernal. 

                No. We using OMAP2(ARM) processor. As you mentioned the above link, there i couldn't the kernel for OMAP2. so could you help us to download kernel for that one.

[Hiep Trinh]

Hi,
I tried to compile perf for android on ubuntu follow the guide on the page
http://stuff.mit.edu/afs/sipb/contrib/linux/tools/perf/Documentation/android.txt
and i have some issues as glibc-devel. When i check, i see that glibc, which is libc6 on ubuntu 12.04, is installed. But i still recieve error: no libc-version.h found, please install glibc-dev/glibc-devel/glibc-static.
If you have compile this tool for android, can you help me, i appreciate any helps from you
Thanks,

Vào 08:16:55 UTC+7 Chủ nhật, ngày 21 tháng mười năm 2012, David A đã viết: