Hi! I've updated to vanilla 2.6.19 on my Pentium-D (dual-core x86_64) box. Now I can't see even C1 in the /proc/acpi/processor/*/power output: patrol@arcus:~$ cat /proc/acpi/processor/CPU1/power active state: C0 max_cstate: C8 bus master activity: 00000000 maximum allowed latency: 2000 usec states: patrol@arcus:~$ cat /proc/acpi/processor/CPU2/power active state: C0 max_cstate: C8 bus master activity: 00000000 maximum allowed latency: 2000 usec states: Another interesting thing is shown here: patrol@arcus:~$ cat /proc/acpi/processor/CPU1/info processor id: 0 acpi id: 1 bus mastering control: no power management: no throttling control: yes limit interface: yes patrol@arcus:~$ cat /proc/acpi/processor/CPU2/info processor id: 1 acpi id: 2 bus mastering control: no power management: no throttling control: no limit interface: no As I remember, both cores were showing the same things formerly. The only line referring to CPUs during boot is ACPI: Processor [CPU1] (supports 8 throttling states) and CPU2 is not mentioned at all. The last (but maybe not acpi-related) strange thing is that in /proc/cpuinfo, CPU1 reports 6403.56 bogomips (as always, approximately twice the clock) and CPU2 8314.32 ones (too much). It's also very suspicious. Formerly the difference was very small. Should I provide more info to debug these things, or is it OK ? With regards, Pavel Troller - 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