Hi Mark,
Mark Haywood wrote:
> It was recently pointed out to me that the CPU driver is printing (a
> very poorly worded) message to the system error log every time it
> receives a _PPC change notification. For those who don't know what a
> _PPC is, it's an ACPI object that informs the OS which of the defined
> P-states are accessible. That is, it's like a governor on which P-states
> the OS should use. It's frequently used by the platform to force the
> processors down to a lower frequency as a thermal control mechanism.
>
> The _PPC can change dynamically and when it does it is possible for the
> OS to find out about the change by registering a change notification
> handler. The CPU driver does register a handler and as I mentioned above
> is printing an error message to the system error log it is invoked.
> Printing the message to the system error log was apparently a mistake.
> Some platforms are changing the _PPC values much more often that I expected.
>
> I've already filed:
>
> 6636222 "NOTICE: cpudrv_pm_set_topspeed: instance 0: has new max power
> of 2000 MHz" needs to go
>
> to remove the message. But was thinking that we might want to add
> another cpu_info kstat to track the current maximum permissible
> frequency for the processor. It would have to be an x86 only kstat
> probably tracked in the cpu_t structure in a similar fashion as
> cpu_curr_clock. I was wondering if anyone had an opinion on the
> usefulness of this data as a cpu_info kstat addition?
From the testing side of things, I think it'd end up being pretty
useful to have that information easily accessible.
Thanks,
Pat
>
> Mark
>
>
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--
Pat Bredenberg
Solaris Quality Engineering
Sun Microsystems, Inc. - Broomfield, CO
