Re: + restore-missing-sysfs-max_cstate-attr.patch added to -mm tree

Len Brown
2008-01-07T22:44:34Z

On Monday 07 January 2008 16:33, Mark Lord wrote:
> Len Brown wrote:
> > 1. Why does VMware need max_cstate=1 to load quickly?
> ..
>
> Eh? Nothing to do with "loading" anything,
> but rather it's simple responsiveness to guest keyboard
> input that we're experiencing trouble with.
> The guest OS is probably "broken" in that regard,
> but setting max_cstate=1 makes it usable here.

okay, then when vmware is loaded, but idle, please run powertop
http://www.lesswatts.org/projects/powertop

and report what you see for C-states, P-states
and wakeup sources.

> > 2. Why does the "max_csate=1" workaround help only
> > on the dual-core boxes, while the single-core
> > boxes still fail to load quickly?
> ..
>
> Eh? Setting max_cstate=1 helps on both single/dual core
> boxes/kernels here. The alternative (newer) latency thing
> (that requires a custom kernel module to change on the fly)
> is the thing that had no effect at all on our single-core box,
> but did seem to help the dual-core more (not verified completely
> on dual-core though).

please report the contents of
cat /proc/acpi/processor/CPU*/power
for both systems when the C-states are not limited.

what latency limit did you specific to the latency I/F?

thanks,
-Len