[dtrace-discuss] dtrace wired issue

Aubrey Li
Mon, 14 Jan 2008 13:43:58 -0000

On Jan 14, 2008 9:38 PM, James C. McPherson <James.McPherson at sun.com>
wrote:
> 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?

No, I want to say, if your cpu is not faster than mine,
but dtrace response is faster than mine, then your explanation
----snip----
All those attach()es and detach()es need time, as does the
probe collation.
----snip----

is not reasonable.

So, there must be something wrong on my system,
but I can''t figure it out so far.

Thanks,
-Aubrey