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

2008/6/11 John Birrell <jb_at_what-creek.com>:
>
> It's been a few weeks now since I committed DTrace support to current.

I'm curious... impact over performances?


>
> To start using DTrace to trace stuff in the kernel (userland tracing
> isn't supported yet), here's what you need to do:
>
> 1.  Grab the latest current sources for the entire src tree.
> 2.  Do a 'make buildworld' of those sources on either a -current system
>    or a releng7 system.
> 3.  Add 'options KDTRACE_HOOKS' and 'options DDB_CTF' to your kernel
>    config file (on i386 or amd64; users of other arches can go watch
>    a movie instead).
> 4.  Do a 'make WITH_CTF=1 buildkernel && make installkernel'

Done, but I get this error
MAKE=make sh /usr/src/sys/conf/newvers.sh GENERIC
cc -c -O -pipe  -std=c99 -g -Wall -Wredundant-decls -Wnested-externs
-Wstrict-prototypes  -Wmissing-prototypes -Wpointer-arith -Winline
-Wcast-qual  -Wundef -Wno-pointer-sign -fformat-extensions -nostdinc
-I. -I/usr/src/sys -I/usr/src/sys/contrib/altq -D_KERNEL
-DHAVE_KERNEL_OPTION_HEADERS -include opt_global.h -fno-common
-finline-limit=8000 --param inline-unit-growth=100 --param
large-function-growth=1000  -mno-align-long-strings
-mpreferred-stack-boundary=2  -mno-mmx -mno-3dnow -mno-sse -mno-sse2
-mno-sse3 -ffreestanding -Werror  vers.c
linking kernel.debug
subr_kdb.o(.text+0x650): In function `kdb_enter':
: multiple definition of `kdb_enter'
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

Stop in /usr/obj/usr/src/sys/NEWK.
*** Error code 1

Stop in /usr/src.
*** Error code 1

Stop in /usr/src.

NEWK=GENERIC without debugging

uname -a  FreeBSD 8.0-CURRENT #3: Sun Jun  8 23:23:55 CEST 2008  i386

thanks in advance

-- 
Diego Depaoli