cvs commit: src/sys/conf files src/sys/modules/acpi/acpi Makefile src/sys/dev/acpica acpi_battery.c acpi_smbat.c acpi_smbus.h acpiio.h

[Nate Lawson]

Dag-Erling Smørgrav wrote:
> Mike Silbersack <silby at silby.com> writes:
> 
>>2.  Now, powerd seems to be causing ~30% system cpu load - top shows
>>it switching between the "nanslp" and "ecpoll" wait states.  This may
>>be due to some other recent change to acpi, I'm not sure how to best
>>test.
> 
> 
> Try running powerd with a 5000 ms polling interval.  With the default
> of 500 ms, it never seems to stabilize, but keeps oscillating wildly
> in the 75-300 MHz range on my Dell Latitude D600.

That is bad for performance.  It can then take up to 10-15 seconds to 
promote back to 100% CPU when your system becomes busy.

I've said it many times: we need a real predictive algorithm.  Taking a 
single sample will always have hysteresis problems.  See the acpi@ list 
archives for much more detail and a good summary, including linked 
papers, here.

http://wikitest.freebsd.org/moin.cgi/powerd

-- 
Nate