Most recent kernel where this bug did *NOT* occur: 2.6.20.3 Distribution: Slackware 11.0 Problem Description: Hi, i have some problems with CPU Throttling and power states of my CPU. I get this report...CPU rest cat /proc/acpi/processor/CPU0/power active state: C4 max_cstate: C8 bus master activity: 00000000 maximum allowed latency: 2000 usec states: C1: type[C1] promotion[C2] demotion[--] latency[001] usage[00000010] duration[00000000000000000000] C2: type[C2] promotion[C3] demotion[C1] latency[001] usage[00502851] duration[00000000000275479975] C3: type[C3] promotion[C4] demotion[C2] latency[085] usage[00000431] duration[00000000000001178354] *C4: type[C3] promotion[--] demotion[C3] latency[185] usage[00053417] duration[00000000000142463775] It should be ok...but... when i start...for example...kernel compilation...state of my busy CPU is this: active state: C2 max_cstate: C8 bus master activity: 80000001 maximum allowed latency: 2000 usec states: C1: type[C1] promotion[C2] demotion[--] latency[001] usage[00000010] duration[00000000000000000000] *C2: type[C2] promotion[C3] demotion[C1] latency[001] usage[00576754] duration[00000000000315228566] C3: type[C3] promotion[C4] demotion[C2] latency[085] usage[00004034] duration[00000000000009452622] C4: type[C3] promotion[--] demotion[C3] latency[185] usage[00099626] duration[00000000000262585789] My question is this: Why my CPU is not in C1 state, when works on 100%? And where is C0 state? I have problems with Throttling function too. my command: echo -n 4 > /proc/acpi/processor/CPU0/throttling state T4 is activated, but only a few seconds and then it goes back to T0. Is this ok? I heard, that Throttling is active only in C0 state. my CPU power management: CPU Frequency scaling ondemand gowernor ACPI Processor P-State driver Intel Enhanced SpeedStep Hardware Environment: Lenovo 3000 C100 (Pentiom M 1.7GHz Dothan) Software Environment: Slackware Linux 11.0
Created attachment 10820 [details] dmesg output this is my dmesg output
it isnt' clear that 1. there is a problem in 2.6.21 2. 2.6.21 is any different than 2.6.20 C0 is the active state -- we don't track residency for that here. C1, C2, C3 etc are cpu idle states where no instructions are executed. It is a known cosmetic bug that we don't put in counts for C1 that we will not fix. Throttling is controlled by the termal sub-system, so yes, if you ask to throttle, it might over-ride your choice. Please re-open if something is wrong that i missed.
*** Bug 8243 has been marked as a duplicate of this bug. ***