Re: [Python-Dev] DTRACE support

On 2013-09-07, at 05:40 , Jesus Cea wrote:

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On 06/09/13 20:33, Antoine Pitrou wrote:

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On Fri, 06 Sep 2013 18:14:26 +0200 Jesus Cea wrote:

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It is intrusive. Yes. I think it must be, by its own nature. Probably room for improvement and code transparency. But... are Python-DEVs interested in the project?. That is the point :)

As a concrete data point: - here are Dave's modifications to ceval.c for systemtap: http://bugs.python.org/review/14776/diff/5177/Python/ceval.c - here are your modifications to ceval.c for dtrace: http://bugs.python.org/review/13405/diff/6151/Python/ceval.c

Unfair, because that code is not doing the same thing.

Most of the extra complexity is there to deal with DTRACE ability to provide meaningful stackframes, with Python code instead of CPython evaluation loop. This is kind of magical.

Antoine will correct me if I'm wrong, but I believe his point is less about the complexity of dtrace provision and more about how much of it lives in ceval.c: the systemtap provision also takes quite a bit of code, but almost all of that code is extracted into a separate file and only a pair of calls live in ceval.c You patch, because it adds quite a bit of complexity to ceval.c, makes reading it significantly more difficult (especially for people who don't care for probe implementations). Dave's more or less doesn't change the complexity of that file (people who don't care for probes don't have to follow the macros to know what they do).