On Thursday 02 August 2007 04:40, Knut Petersen wrote: > Kernel 2.6.22 decreases performance by about 50% on my system. > No, I do not like that. The reason is a broken BIOS, granted, but there > was a perfect workaround in the kernel that has been dropped. > > mainboard: AOpen i915GMm-hfs, AWARD BIOS > cpu: Pentium-M 750 (0.8 to 1.86 MHz) > openSuSE 10.2 with kernel 2.6.22.1 > > The cpu fan can not be controled by linux kernel. > The BIOS will switch on the cpu fan a bit above 50 deg. Celsius. > The active and passive trip points both are set to 50 deg. Celsius. > Temperature of the idle cpu at 800 Mhz: 34 to 42 deg. C. > The BIOS never changes the trip points. > Cpufreq does work perfectly. > > Previously there was the possibility to add something like > > echo "100:0:65:70:0" > /proc/acpi/thermal_zone/THRM/trip_points > echo 2 > /proc/acpi/thermal_zone/THRM/polling_frequency > echo ondemand > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor > > to e.g. /etc/init.d/boot.local. With 2.6.22 that solution does not exist > any longer. Now the code in thermal.c slows down the cpu under load > to prevent "overheating". Kernel compile time increases from about 12 > to 18 minutes. No, I don´t like that, nobody would. Thanks for the sighting, Knut! This regression is dramatic when put in the terms of 50% performance hit! I guess the good news is that thermal throttling is doing the job we are asking it to:-) The statement above regarding the existence of active trip points and the kernel not being able to control the fan are inconsistent with each other. Please open a sighting for this machine here: http://bugzilla.kernel.org/enter_bug.cgi?product=ACPI vs. Power-Thermal and attach the output from acpidump, cat /proc/acpi/thermal_zone/*/* and assign it to len.brown@xxxxxxxxx BTW. does the board boot and run properly with "acpi=off"? thanks, -Len - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
