[dtrace-discuss] dtrace wired issue

James C. McPherson
Mon, 14 Jan 2008 13:38:02 -0000

Aubrey Li wrote:
> On Jan 14, 2008 9:26 PM, Aubrey Li <aubreylee at gmail.com> wrote:
>> On Jan 14, 2008 9:22 PM, James C. McPherson <James.McPherson at
sun.com> wrote:
....
>>> If you run "dtrace -l" with no args, *every* single
loadable
>>> module on the system will be loaded, interrogated by dtrace
>>> and then unloaded if possible.
>>>
>>> All those attach()es and detach()es need time, as does the
>>> probe collation.
>>>
>> So may I ask, how long "dtrace -l" get response on your
system?
>> And how fast the cpu speed on your system?
>>
>> 4 minutes, it is absolutely acceptable for me.
>>
> err, sorry, I mean unacceptable, ;-)

(figured that :)

*** On a u20m2

$ uname -a
SunOS farnarkle 5.11 snv_77 i86pc i386 i86pc
$ su root -c ''time dtrace -l > /dev/null''
Password:

real        2.2
user        0.1
sys         1.0
$ psrinfo -v
Status of virtual processor 0 as of: 01/14/2008 23:32:17
   on-line since 01/08/2008 09:11:53.
   The i386 processor operates at 2200 MHz,
         and has an i387 compatible floating point processor.
Status of virtual processor 1 as of: 01/14/2008 23:32:17
   on-line since 01/08/2008 09:11:56.
   The i386 processor operates at 2200 MHz,
         and has an i387 compatible floating point processor.



*** on a u20

# time dtrace -l > /dev/null

real    0m0.219s
user    0m0.063s
sys     0m0.089s
# psrinfo -v
Status of virtual processor 0 as of: 01/14/2008 23:33:12
   on-line since 01/14/2008 22:43:46.
   The i386 processor operates at 2412 MHz,
         and has an i387 compatible floating point processor.
Status of virtual processor 1 as of: 01/14/2008 23:33:12
   on-line since 01/14/2008 22:43:50.
   The i386 processor operates at 2412 MHz,
         and has an i387 compatible floating point processor.

# uname -a
SunOS crashburn 5.11 snv_80 i86pc i386 i86pc





*** on a u60

# time dtrace -l > /dev/null

real        4.4
user        0.9
sys         3.2
# psrinfo -v
Status of virtual processor 0 as of: 01/14/2008 23:47:33
   on-line since 09/14/2007 21:44:39.
   The sparcv9 processor operates at 296 MHz,
         and has a sparcv9 floating point processor.
Status of virtual processor 2 as of: 01/14/2008 23:47:33
   on-line since 09/14/2007 21:44:41.
   The sparcv9 processor operates at 296 MHz,
         and has a sparcv9 floating point processor.

# uname -a
SunOS synergise 5.11 snv_71 sun4u sparc SUNW,Ultra-60




You seem to be convinced that cpu is the limiting
factor. Why?



James C. McPherson
--
Senior Kernel Software Engineer, Solaris
Sun Microsystems
http://blogs.sun.com/jmcp	http://www.jmcp.homeunix.com/blog