Re: [PATCH 3/6] 2.6.16-rc1 perfmon2 patch for review

["Bryan O'Sullivan" <bos@serpentine.com>]

On Wed, 2006-01-25 at 21:43 -0800, Stephane Eranian wrote:

> This one contains statistics about perfmon such as PMU model, number of active
> sessions, and also a bunch of per-cpu statistics (see attached file).
> 
> $ cat /proc/perfmon
> perfmon version            : 2.2
> PMU model                  : Intel Pentium M
> PMU description version    : 1.0
> counter width              : 31
> loaded per-thread sessions : 0
> loaded sys-wide   sessions : 0
> current smpl buffer memory : 0
> format                     : d1-39-b2-9e-62-e8-40-e4-b4-02-73-07-87-92-e9-37 default_format2
> CPU0   total ovfl intrs    : 0
> CPU0     spurious intrs    : 0
> CPU0     replay   intrs    : 0
> CPU0     regular  intrs    : 0
> CPU0   overflow cycles     : 0
> CPU0   overflow phase1     : 0
> CPU0   overflow phase2     : 0
> CPU0   overflow phase3     : 0
> CPU0   smpl handler calls  : 0
> CPU0   smpl handler cycles : 0
> CPU0   set switch count    : 0
> CPU0   set switch cycles   : 0
> CPU0   handle timeout      : 0
> CPU0   owner task          : -1
> CPU0   owner context       : 00000000
> CPU0   activations         : 0

Is there any reason you might need those per-CPU statistics in an atomic
snapshot form?  That seems unlikely, off the top of my head.  You could
either have a per-CPU directory with a file for each counter, which
seems cleanest, or a per-CPU file with all counters and the name of
each, although the format wants cleaning compared to what you have now.

	<b