[dtrace-discuss] maximum program size?

[Bryan Cantrill]

On Sat, Dec 01, 2007 at 09:17:43AM -0800, Rich Morin wrote:
> I just got the following nastygram:
> 
>   dtrace: failed to enable 'probes.tmp':
>     DIF program exceeds maximum program size

Yeah, I figured you might run into this limitation.  There is a DOF size
limitation that most normal DTrace users don't run into, but most people
automatically generating (massive) scripts ultimately do.  This is discussed
in our "Advanced DTrace: Tips, Tricks and Gotchas" presentation:

  http://blogs.sun.com/roller/resources/bmc/dtrace_tips.pdf

This "gotcha" is discussed on slide 14.  The executive summary is that you
need to tune dtrace_dof_maxsize up from its default of 256k.  In Solaris,
this is done statically via /etc/system or dynamically via mdb -- but I
don't know how kernel variables are tuned in MacOS.  Apple folks?

(And yes, the "Advanced DTrace" presentation now really should be wiki-ized.)

	- Bryan

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Bryan Cantrill, Sun Microsystems FishWorks.       http://blogs.sun.com/bmc