Re: Systemtap on the ARM processor....

[naresh kamboju <naresh dot kernel at gmail dot com>]

Hi,

On Wed, Mar 17, 2010 at 12:50 AM, Frank Ch. Eigler <fche@redhat.com> wrote:
> Steve Dickson <SteveD@redhat.com> writes:
>
>> Has a ARM port ever been attempted? If so, by whom?
I have been using SystemTap version from 0.9.5 to 1.0 on ARM
architecture and with my local patches.

>> If not, any guesstimates on how difficult that would be?
>
> Versions of systemtap has run on ARM for quite some time. ?I don't
> recall whether people have had success running stap on a native
> installation, with ARM machines' RAM often being so puny, but in
> principle that should work fine. ?Another way has been to use stap's
> native cross-compilation facilities (installing an arm kernel build
> tree, arm cross-compiler toolchain, and using "stap -p4 -a armel-blah"
> to build modules). ?A stap-server/-client installation be able to make
> this somewhat more automatic.

I agree with you Frank.
Your point is valid since ARM architectures having very poor RAM in
size, building Systemtap and Kernel on ARM architecture takes couple
of hours. Most of the times the RAM size would be 64 MB or 128 MB so
it needs additional swap space on the hard disk.

To make the systemtap easy to build and test.
1.	Cross compile the systemtap source and install
	by using ARM cross tool chain arm-linux-gnueabi-
2.	Build ARM kernel image and install modules under /lib/module/XXXX
on the X86 Host machine.
3.	Build the systemtap testsuite by using below command on Host
buildok# stap -p4 -vv -a arm -B
CROSS_COMPILE=/usr/local/arm-linux-gnueabi/cross/devel/bin/arm-linux-gnueabi-dev-
-r 2.6.29.4-rt19-dirty -m array_size array_size.ko

4.	on ARM board  target run below command to inster .ko
#staprun array_size.ko

Building .ko modules and copy to target board with ssh password less
and execute and get the out put of each test case will be done by my
local automation scripts.

I could build 308 .ko out of 622 stp files. Because most of the test
cases designed to build and execute directly on target. For example
set –e and stap –e and many more with upto -p1 and –p2 parse which can
not build .ko by using –p4

For the cross compilation we could not use “make check” mechanism to
test on ARM target boards. I could do only insertion of cross compiled
.ko

I think we should take initiative on this and modify the testsuite to
compatible with cross compilation. Of course it may required more
efforts in term of time.

Frank,
I hope you would the right person to reply to this request.
Please give me initial design for cross compile compatible testsuite.
I am ready to work on to make whole systemtap compatible with cross compilation.

>
> I believe there is no uprobes port for arm, so user-space probing
> (process.*) will not be avialable.
>
> - FChE
>
Best regards
Naresh Kamboju