cvs commit: src/etc/defaults rc.conf
nate at root.org
Sat Jan 28 22:17:32 PST 2006
Kris Kennaway wrote:
> On Sun, Jan 29, 2006 at 01:06:54AM -0500, Kris Kennaway wrote:
>>On Sun, Jan 29, 2006 at 05:51:58AM +0000, Nate Lawson wrote:
>>>njl 2006-01-29 05:51:58 UTC
>>> FreeBSD src repository
>>> Modified files:
>>> etc/defaults rc.conf
>>> Enable the lowest Cx state by default. This will save power and we have
>>> had enough testing of acpi_cpu to know this is stable now.
>>On my desktop system (running RELENG_6 though), setting
>>hw.acpi.cpu.cx_lowest=C0 causes atrocious performance. Is it broken
> C2, sorry.
Ah, C0 should be disallowed already I thought (try it).
As for C2, I MFCd a patch to acpi_cpu.c in November that should prevent
this (188.8.131.52). Do you get a printf on console?
If we're trying to use C2/3 and reads from the register are returning
immediately, back off to the next higher Cx sleep state. Some machines
with a Via chipset report a valid C3 but a register read doesn't
actually halt the CPU. This would cause the machine to appear
unresponsive as it repeatedly called cpu_idle() which immediately
returned. Causing interrupts (i.e. by pressing the power button) would
cause the system to make forward progress, showing that it wasn't
Also, enable interrupts a little earlier. We don't need them disabled
to calculate the delta time for the read.
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