RE: Systemtap on the ARM processor....

["Goeusse, Francois" <f-goeusse at ti dot com>]

Hi,

Would it be possible to work on getting those patches into the upstream
SystemTap package?
-> Before doing so, it may be recommended to explain how these patches were 'found'.
Actually, rel 1.0 did not seem to properly work for ARM core as is. However, some information on the web clearly mentioned that previous systemtap releases could be used with ARM cores. Therefore, these patches deal with (or cancel) the code updates between 1.0 and older releases which seemed to specifically prevent systemtap from properly operating on ARM.
Therefore, before submitting any changes into the upstream and guarantee the backward compatibility for all platforms, it may be preferable to check what motivated these particular code updates?
This is question where a longer/better expertise in the tool code may be preferable.
Any opinion on this?

Is the kernel/arch/arm/include/asm/ptrace.h patch needed for systemtap?
-> Might be different for a more recent release of the tool, but yes this was needed for rel 1.0 (these lines were part of previous releases of the kernel).

The wiki page mentions a library of scripts at: http://omappedia.org/wiki/Systemtap
Are any of those general purpose that would be useful for other platforms?
-> Generic scripts should become available progressively (timeframe still under discussion). They do not comply with the guidelines yet... but they will have to ;-)
Then, there should no issue with submitting these scripts to the examples directory.

Francois


Texas Instruments France SA, 821 Avenue Jack Kilby, 06270 Villeneuve Loubet. 036 420 040 R.C.S Antibes. Capital de EUR 753.920

-----Original Message-----

From: systemtap-owner@sourceware.org [mailto:systemtap-owner@sourceware.org] On Behalf Of William Cohen
Sent: mercredi 31 mars 2010 22:46
To: systemtap@sourceware.org
Subject: Re: Systemtap on the ARM processor....

On 03/29/2010 09:40 AM, Goeusse, Francois wrote:
> Hi,
>
> Systemtap is being tested on TI OMAP platforms (ARM based) for a couple of months.
> If this can help, some resulting quick guidelines have been captured and are shared with the community at the following url: http://omappedia.org/wiki/Systemtap
>
> Based on documentation delivered with systemtap and these perfectible guidelines, the tool is now functional and already significantly helps for the ARM platform debug and characterization.
>
> As you will probably notice, systemtap rel 1.0 required some minor code tuning (kernel and tool) to run on our ARM based platform (OMAP/Android, OMAP/Poky).
> Furthermore, as of today, the test coverage remains incomplete as the testsuite does not seem to fully comply with cross compilation (as mentioned by Naresh as well).
>
> Because we have not yet migrated to the latest releases of the tool, some of these code updates might no longer be required.
> However, if you believe systemtap ARM users can assist you in a way or another in the product maturation on their platforms, I guess the discussion can surely be opened.
>
> Regards,
>
> Francois

Hi Francois,

It is nice to see a web page describing how to use systemtap on ARM in more detail:

http://omappedia.org/wiki/Systemtap


Having separate patches is a pain. Would it be possible to work on getting those patches into the upstream SystemTap package? It looks like some of the patches will need to be reworked to ensure the don't cause systemtap to fail on non-ARM machines.

Is the kernel/arch/arm/include/asm/ptrace.h patch needed for systemtap? I didn't see anywhere in the systemtap or its runtime code that condition_codes() is used.

The wiki page mentions a library of scripts at: http://omappedia.org/wiki/Systemtap

Are any of those general purpose that would be useful for other platforms? Any submissions to the examples directory would be appreciated. Information on how to get examples included in systemtap examples directory is at:

http://sources.redhat.com/git/gitweb.cgi?p=systemtap.git;a=blob_plain;f=testsuite/systemtap.examples/README;hb=HEAD

-Will