Re: [PATCH 0/9] Add support for DTrace USDT probes to gdb

Sergio Durigan Junior
2014-10-08T19:40:50Z

On Friday, September 26 2014, Jose E. Marchesi wrote:

> This patch series introduces support in GDB for a new type of probe:
> DTrace USDT probes.
>
> The first three patches do some changes to the existing probe.[ch]
> code, fixing some minor problems associated to support several probe
> types, having several probes of different types defined in the same
> object and supporting the notion of enabling and disabling probes.
>
> The rest of the patches are the implementation of the new probe type,
> including target support for x86_64 targets, a testsuite and
> documentation.

OK, I think I reviewed all the patches (except the docs). First of all,
thanks for doing this!

I have mixed feelings about the inclusion of this feature. While I
obviously agree that support for a new probe type is good, I also don't
like the fact that we are talking about a feature that relies on
proprietary software (Oracle dtrace) to operate.

For example, when trying to test this here, I naively thought that using
something like "dtrace4linux" (<https://github.com/dtrace4linux>) would
be enough. It wasn't. So you kindly helped me with this, but I
know that other people who decide to test GDB might not be lucky to have
Jose helping them :-).

You mentioned that you were going to try to come up with some way to
test this feature using a tweaked asm source. I think this is a good
progress already, and I am looking forward to seeing this.

Either way, if we decide to include this feature on GDB, you (or someone
else from Oracle) will be responsible for it, because we outside Oracle
have no way to make sure that it doesn't break.

Having said that, I will wait until you post updated patches with our
comments addressed (and hopefully with a nice testcase :-P), and then we
can continue this discussion :-).

Cheers,

--
Sergio
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