So this brings up a question that I think I've asked before and not seen 
an answer to. The discussion here seems to be around a C-state driver, 
not a CPU driver? Does this mean that the C-state support will be in a 
driver of its own? Or is it going to be functionality provided by the 
CPU driver?

Given that Aubrey wanted the CPU driver initialization restructured, I 
assumed that he was planning on one driver.

Thanks,
Mark

Bill Holler wrote:
> Aubrey, Eric, and I had an email discussion of the c-state driver which
> I will try to paraphrase here. Here is a list of the pieces being worked on:
> 
> 1. Detect which c-states are supported.
> 
> Aubrey is almost done with the work to gather this information parsing
> ACPI tables. This will be merged in with Mark's workspace.
> 
> 
> 2. Determine what Solaris needs to do to bring processors into each
> deeper c-state. This includes tsc/APIC timer re-sync on power up,
> power aware scheduler, interrupt redistribution (with power awareness),
> and have a system-wide "policy engine" that may need to be aware of
> each cpu idle time statistics and c-state latencies.
> 
> Eric and others have spent time on these. I will see how far they are
> and may be help out here.
> 
> 
> 3. Design code that will be aware of c-states, operations needed to make
> c-state transitions, and estimated cost or latency to enter/exit each 
> c-state.
> 
> Aubrey is working on this.
> 
> 
> 4. Design a policy interface in the c-state driver.
> We should probably have an independent policy engine that can take
> input from the user regarding which policy they want (maximize
> performance, max power savings, on battery, etc). We also need some
> independent code that is aware of the whole system and can coordinate
> the dispatcher, interrupts, and each individual cpu's idle c-states.
> We also probably want a testing interface for specifying different idle
> c-state strategies.
> 
> We need a way for this individual code to specify to the c-state driver
> what it should do on each cpu.
> 
> Regards,
> Bill Holler
> 
> 
> 
> 
> _______________________________________________
> tesla-dev mailing list
> tesla-dev at opensolaris.org
> http://mail.opensolaris.org/mailman/listinfo/tesla-dev


Reply via email to