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Re: [PATCH] instruction tracing probe


Dave Nomura <dcnltc@us.ibm.com> writes:

> I'll check out the man pages.  I forgot to look for them.

Plus src/NEWS for new syntax/features.  Please grok src/HACKING.

> 1) user program must be started first so that it's pid can be known to
> the systemtap session. [...]

That's not so hard: have the dejagnu script execute some process in
the background; collect the PID; pass it to the systemtap script.

> 2) the user program has to be delayed long enough to let the
> systemtap session to start up and do some itrace initialiation.

Maybe not.  If the user program is some CPU sucker like
'sh -c "while true; do; done;"', it's all about the same.

Plus you don't have to enable the itrace mode simply on the basis of
uprobes events.  You can just enable it for the whole duration of the
probe script.  Or turn it on and off based on procfs controls.  Or
system calls.  Or timers.  Or whatever.


- FChE


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