Re: perfmon not counting idle?

Re: perfmon not counting idle?

[Stephane Eranian]

Matt,

On Tue, Oct 18, 2005 at 03:44:53AM +1000, Matt Chapman wrote:
> I am probably missing something blatantly obvious due to lack of sleep,
> but, I can't seem to get perfmon to include the idle task.
> 
> I booted with nohalt and even commented out pm_idle and safe_halt in the
> idle loop, to try and make sure that power management isn't kicking in,
> but I still get numbers that seem to exclude idle time.
> 
> torrone:~# pfmon --system-wide
> <press ENTER to stop session>
>   ... run for a few seconds ...
> CPU0                       69597 CPU_CYCLES
> 
By default pfmon measures only at the user level (pl3).  If you want
kernel+user you need to add -k. You can tune priv levels per event
using --prev-levels.

perfmon not counting idle?

[Matt Chapman]

I am probably missing something blatantly obvious due to lack of sleep,
but, I can't seem to get perfmon to include the idle task.

I booted with nohalt and even commented out pm_idle and safe_halt in the
idle loop, to try and make sure that power management isn't kicking in,
but I still get numbers that seem to exclude idle time.

torrone:~# pfmon --system-wide
<press ENTER to stop session>
  ... run for a few seconds ...
CPU0                       69597 CPU_CYCLES

If I look at /proc/perfmon in the meantime, everything looks in order,
and exclude idle is 0:

torrone:~# cat /proc/perfmon
perfmon version           : 2.0
model                     : Itanium 2
fastctxsw                 : No
expert mode               : No
ovfl_mask                 : 0x7fffffffffff
PMU flags                 : 0x1
proc_sessions             : 0
sys_sessions              : 1
sys_use_dbregs            : 0
ptrace_use_dbregs         : 0
format                    : 4d-72-be-c0-06-64-41-43-82-b4-d3-fd-27-24-3c-97 default_format
CPU0  overflow intrs      : 0
CPU0  overflow cycles     : 0
CPU0  overflow min        : 18446744073709551615
CPU0  overflow max        : 0
CPU0  smpl handler calls  : 0
CPU0  smpl handler cycles : 0
CPU0  spurious intrs      : 0
CPU0  replay   intrs      : 0
CPU0  syst_wide           : 1
CPU0  dcr_pp              : 1
CPU0  exclude idle        : 0
CPU0  owner               : 1920
CPU0  context             : e00000407d288000
CPU0  activations         : 0

This is Linux 2.6.12 on a Madison CPU.

Am I doing something wrong?

Matt

Re: perfmon not counting idle?

[Matt Chapman]

On Mon, Oct 17, 2005 at 02:32:17AM -0700, Stephane Eranian wrote:
> By default pfmon measures only at the user level (pl3).  If you want
> kernel+user you need to add -k. You can tune priv levels per event
> using --priv-levels.

Ah, oops.  Thanks :)

Matt