Getting started with DTrace in FreeBSD-current (a.k.a. 8)

Diego Depaoli trebestie at
Thu Jun 12 22:20:34 UTC 2008

2008/6/12 John Birrell <jb at>:
> On Thu, Jun 12, 2008 at 11:38:50PM +0200, Diego Depaoli wrote:
>> 2008/6/11 John Birrell <jb at>:
>> >
>> > It's been a few weeks now since I committed DTrace support to current.
>> I'm curious... impact over performances?
> DTrace is supposed to be low impact until you enable probes.

> When you enable
> probes, the impact depends on how many probes, how often they are called
> and what the actions do.
Sounds logic

>> kern_dtrace.o(.text+0x1e0): first defined here
>> ld: Warning: size of symbol `kdb_enter' changed from 34 in
>> kern_dtrace.o to 70 in subr_kdb.o
>> *** Error code 1
> Try removing the #ifndef and the code it contains in kern_dtrace.c.
> It looks like the kdb_enter function is always compiled in.
Make kernel goes right, now I reboot.

Many thanks

Diego Depaoli

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