DTrace gone quiet?

[Mark Johnston]

On Tue, Apr 16, 2013 at 12:57:08PM -0700, Navdeep Parhar wrote:
> I just upgraded my kernel and userspace to head (r249552) and I notice
> that DTrace doesn't output anything until I hit ctrl-c.  All previous
> "hits" on the probe appear lost.  For example:
> 
> # dtrace -n 'fbt::ether_output:entry'
> dtrace: description 'fbt::ether_output:entry' matched 1 probe
> 
> (No output here.  I waited a long time before the ctrl-c and I know the
> system is actively transmitting and receiving Ethernet traffic).
> 
> ^C
> CPU     ID                    FUNCTION:NAME
>   9  29354               ether_output:entry
>   8  29354               ether_output:entry
>   8  29354               ether_output:entry
>   8  29354               ether_output:entry
> 
> 
> Can anyone confirm or contradict this on a recent HEAD (around r249552
> in my case)?

Reverting r249367 and rebuilding libdtrace+the kernel fixes the problem
for me.

-Mark