Discussion:
general documentation of all dtrace probes
goinsane
2010-11-24 13:25:30 UTC
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Is there a complete overview and documentation of all probes available?
I'm wondering about the guys who are using probes like

fbt:sockfs:sotpi_accept:

and do processing of arguments I've no idea where these are taken from. -(

regards, goinsane
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This message posted from opensolaris.org
James Carlson
2010-11-24 13:40:39 UTC
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Post by goinsane
Is there a complete overview and documentation of all probes available?
I'm wondering about the guys who are using probes like
and do processing of arguments I've no idea where these are taken from. -(
"fbt" is "function based tracing." I'd expect that the 'documentation'
of these is essentially the source code itself.

For things that are in section 9F of the man pages, the man page should
provide adequate documentation. But for things not present there,
there's at most a detailed design document available from the original
project team that wrote the code, and likely not even that.

You might want to review the dtrace "stability level" information in the
tracing guide.
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James Carlson 42.703N 71.076W <carlsonj-dlRbGz2WjHhmlEb+***@public.gmane.org>
Adam Leventhal
2010-11-24 14:31:35 UTC
Permalink
Post by goinsane
Is there a complete overview and documentation of all probes available?
I'm wondering about the guys who are using probes like
and do processing of arguments I've no idea where these are taken from. -(
"fbt" is "function based tracing."  I'd expect that the 'documentation'
of these is essentially the source code itself.
(Function boundary tracing actually) Indeed, the source code is the
documentation.
You might want to review the dtrace "stability level" information in the
tracing guide.
That's right. Stable probes are documented (or should be) whereas
unstable probes don't have semantic meanings that scripts can rely
upon.

Adam
--
Adam Leventhal, Delphix                        http://dtrace.org/blogs/ahl
goinsane
2010-11-24 14:43:45 UTC
Permalink
Post by James Carlson
"fbt" is "function based tracing." I'd expect that
the 'documentation'
of these is essentially the source code itself.
That's right. A understanding of the source seems essential. Unfortunately I'm feeling lost between thousands of symbols, typedefs and lines of code.
Post by James Carlson
For things that are in section 9F of the man pages,
the man page should
provide adequate documentation. But for things not
present there,
there's at most a detailed design document available
from the original
project team that wrote the code, and likely not even
that.
You might want to review the dtrace "stability level"
information in the
tracing guide.
--
James Carlson 42.703N 71.076W
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dtrace-discuss mailing list
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This message posted from opensolaris.org
James Carlson
2010-11-24 15:00:44 UTC
Permalink
Post by goinsane
Post by James Carlson
"fbt" is "function based tracing." I'd expect that
the 'documentation'
of these is essentially the source code itself.
That's right. A understanding of the source seems essential. Unfortunately I'm feeling lost between thousands of symbols, typedefs and lines of code.
Well, at least in the US we've got a long weekend coming. Time to
study. ;-}

Seriously, though, there are some books that may be helpful. "The Magic
Garden Explained" does a pretty good job of explaining the internals of
System V Release 4, which is at least the basis for much of OpenSolaris.

There's no substitute, though, for reading the code. One really good
way to learn how the code works is to trouble-shoot a problem. You'll
be motivated (and forced) to figure out what the code is doing.

Another good way to get going is to look at other D scripts that folks
have written. You can find quite a few by searching the web (in
addition to the ones in /usr/demo/dtrace).

If you don't feel that's a good path for you, then you might want to
search around for layered tools built on top of dtrace and/or
consultants who can help with the task you have at hand.
--
James Carlson 42.703N 71.076W <carlsonj-dlRbGz2WjHhmlEb+***@public.gmane.org>
Adam Leventhal
2010-11-24 15:04:28 UTC
Permalink
Post by goinsane
"fbt" is "function based tracing."  I'd expect that
the 'documentation'
of these is essentially the source code itself.
That's right. A understanding of the source seems essential. Unfortunately I'm feeling lost between thousands of symbols, typedefs and lines of code.
Well what are you trying to do?

Adam
--
Adam Leventhal, Delphix                        http://dtrace.org/blogs/ahl
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