dtrace discuss - Nov 2010 - general documentation of all dtrace probes

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
-- 
This message posted from opensolaris.org

goinsane wrote:
> 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. -(
"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.

-- 
James Carlson         42.703N 71.076W         <carlsonj at
workingcode.com>

>> 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. -(
>
> "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

> "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.
> 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
>         <carlsonj at workingcode.com>
> _______________________________________
> dtrace-discuss mailing list
> dtrace-discuss at opensolaris.org
>
-- 
This message posted from opensolaris.org

goinsane wrote:
>> "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 at
workingcode.com>

>> "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