Updated acpi_cpu patch
l.ertl at univie.ac.at
Tue Nov 18 13:37:30 PST 2003
On Tue, 18 Nov 2003, Nate Lawson wrote:
> On Tue, 18 Nov 2003, Lukas Ertl wrote:
> > hw.acpi.cpu.cx_supported: C1/1 C2/1 C3/85
> > hw.acpi.cpu.cx_lowest: 0
> > hw.acpi.cpu.cx_history: 86231/0 0/0 0/0
> Try settings of cx_lowest of 1 and 2 (and 3 when the last C3 state is
> available). I'm interested in any benchmark results, especially IO. I'm
> hoping the scheduling of sleeps is good enough that you don't experience
> much performance loss even with lower sleeps.
I'm gonna try some "buildkernelstones" with the different settings. If
you have some special benchmarks in mind I'd be happy to run them.
> > Although it seems I have lost a C3 state (before, I had an additional
> > C3/185).
> _CST can change dynamically at runtime. If you booted with the AC adapter
> attached, your laptop may not offer all the sleep states. When you unplug
> the AC adapter, we get a notify on _CST to re-evaluate it and look for new
> states. However, that code is currently disabled due to complex locking
> issues (i.e. what to do when a Cx state is being accessed but _CST is
> being re-evaluated). _CST re-evaluation won't be enabled until after
> 5.2R. However, you can reboot your laptop with the AC adapter detached
> (or attached) to see what states are available.
Ah, yes, that would explain it - I just booted on battery.
> This excerpt from truckman@'s asl shows that 4 Cx states are only
> available when the AC adapter is not attached. (The C*NA memory addresses
> appear to be managed by the BIOS and not the AML but the PSR access is
This part of the ASL looks the one here - let me guess, is it a ThinkPad?
Lukas Ertl eMail: l.ertl at univie.ac.at
UNIX Systemadministrator Tel.: (+43 1) 4277-14073
Vienna University Computer Center Fax.: (+43 1) 4277-9140
University of Vienna http://mailbox.univie.ac.at/~le/
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