Subject: Re: [PATCH] powerpc: Instrument Hypervisor Calls

From: Geoff Levand <[email-masked]>
Date: Mon, 14 Aug 2006 19:01:39 -0700

Mike Kravetz wrote:
> On Mon, Aug 14, 2006 at 04:35:12PM -0700, Geoff Levand wrote:
>> Mike Kravetz wrote:
>> > +config HCALL_STATS
>> > +	bool "Hypervisor call instrumentation"
>> > +	depends on PPC_PSERIES && DEBUG_FS
>> > +	help
>> > +	  Adds code to keep track of the number of hypervisor calls made
> and
>> > +	  the amount of time spent in hypervisor calls: both wall time
> (based
>> > +	  on time base) and cpu time (based on PURR).  A directory named
>> > +	  hcall_inst is added at the root of the debugfs filesystem.
>> 
>> Could we keep this more generic and not mention platform specific
>> things like PURR?
> 
> Not sure if I follow.  PURR will be used/displayed if available.  Time
> based statistics will always be available.
> 
> I can change the description to make this clear.  Or, are you asking
> that this not be mentioned at all?  Based on previous discussions, I
> added the ability to display both wall and cpu time if available.

I want to hook my instrumentation into this config option also, but my
platform dosn't have PURR, so I would like you to remove the mention
of '(based on PURR)' in the description of the option.  This way we
can have a generic 'Hypervisor call instrumentation' option for users,
on whatever platform they are using.

Does it make sense?

-Geoff