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Date: Fri, 28 Nov 2008 11:57:02 -0800
From: Tim Kientzle <kientzle@freebsd.org>
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Cc: freebsd-current@freebsd.org, Ivan Voras <ivoras@freebsd.org>
Subject: Re: HOWTO in wiki: adding custom dtrace probes in the kernel
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>>  SDT_PROBE(foobar, source_file1, foo, entry, a, b, 0, 0, 0);
>>
>> Here: why are the last three arguments zeroes?
> 
> SDT_PROBE() is a macro with a fixed number of macros, so we have to  
> fill with 0 in case we don't want to provide some data. Maybe there's  a 
> way to provide more arguments if you do it by hand instead of using  the 
> SDT_PROBE() macro (TODO item added in the wiki to have a look at  this, 
> feel free to improve the wiki page).

Seems that SDT_PROBE() should be using C99s "variadic macro"
feature.

Tim