[DTrace] DTrace troubleshooting

[Brendan Gregg]

G'Day Folks,

A few of us were discussing today why SMC took so long to boot the first
time, so I pulled out DTrace and started looking. Pretty quickly we had a
good idea why (eg, several million 1 byte read()s), and as it made for a
nice demo of DTrace I just wrote a website for it.

   http://www.brendangregg.com/DTrace/smc.html

I was careful not to suggest that these reads were actually a bug or a
problem; I haven't read the source to SMC, I can only assume there is a
good reason for this behaviour.

Why I'm writing is if anyone thinks I should be more careful about what I
say about SMC, please let me know. It's a good demo of DTrace, I wouldn't
want people to misinterpret it as highlighting an SMC problem that may
well not be a problem...

thanks,

Brendan

[Sydney, Australia]