System Software Meeting Minutes, 2006-09-25

[Jordan Crouse]

On 27/09/06 13:43 -0400, Tom Sylla wrote:
> Actually, GX has many performance counters, in some cases, more detailed
> than pentium or A64 counters. The main problems are that no one has added
> the mappings and support for them to oprofile. Note that the GX counters are
> unable to cause interrupts like those in A64 or Pentium, so you would have
> to run oprofile in RTC or timer mode (which isn't so horrible).

Unfortunately, our performance counters don't have the ability to interrupt
on rollover, which is what oprofile uses as its trigger.

Timer mode does work OK, its just that your profiling isn't as detailed,
and you miss out on those situations where interrupts are disabled.  It
should be enough for nominal userland monitoring though.

Jordan

-- 
Jordan Crouse
Senior Linux Engineer
Advanced Micro Devices, Inc.
<www.amd.com/embeddedprocessors>