Re: [HACKERS] Dynamic Tracing docs

Simon Riggs napsal(a):
> On Sat, 2006-12-02 at 09:43 +0100, Peter Eisentraut wrote:
>> Simon Riggs wrote:
>>> Enclose new trace.sgml file as discussed on -docs.
>> I have a question here, regarding this:
>>
>>    To include DTrace support in a 64-bit binary, specify --enable-dtrace
>>    and DTRACEFLAGS="-64" to configure.
>>
>> The dtrace documentation says that dtrace automatically picks the right
>> build environment.  Something is wrong here.  Either the dtrace
>> documentation or ours.
>
> I didn't presume to question Robert's technical notes
> http://blogs.sun.com/robertlor/entry/user_level_dtrace_probes_in
>
> Robert, Can you throw any light on this? Or do you have any further
> comments on the docs?
> http://developer.postgresql.org/pgdocs/postgres/dynamic-trace.html
>

I'm not dtrace guru, but I think that main reason for 64-bit flag is
that dtrace generates header file/code for probes during preprocessing
time and it don't know nothing about compiler switch. The probe code/
data structure is different on 32/64-bit.

However, if you run dtrace script that dtrace detects automatically
"build environment" (if binary is 32 or 64bits).


Robert, please correct me if I wrong.

    Zdenek