kernel-2.6.25-rc2, CPU C state "active state" always remain C0 unchangeable by cat 'proc/'

On Fedora9 Alpha with kernel-2.6.25-rc2, I run " watch -n 0.1 "cat /proc/acpi/processor/CPU*/power | grep 'active state'" ", I find that the CPU C state information "active state" remain at "C0" and it do not change any time. The same issue also exit on 2.6.24-rc2 kernel. But with RHEL5.1 kernel-2

From 2.6.24 to 2.6.25-rc2, CPU can not do hotplug when one task set affinity to it

In SMP sever platform, with kernel 2.6.24-rc2 and kernel 2.6.25-rc2, Set one task affinity to one CPU core, then set offline the CPU core. After that we can not set online the CPU core again. 1. run the test.sh script: test.sh 1 ( 1 is the logical CPU ) test.sh script: #!/bin/bash main(){

In /proc/cpuinfo, all processor items show "0"

Build kernel 2.6.24-rc3, cat /proc/cpuinfo, all processor items show "0": processor : 0 vendor_id : GenuineIntel cpu family : 15 model : 6 model name :Genuine Intel(R) CPU 3.40GHz stepping: 8 cpu MHz : 3391.555 cache size

ipmi_watchdog can not reset the kernel panic machine

Build kernel-2.6.24-rc3. pmi_watchdog can not reset the kernel panic machine. The watchdog can never to record panic information to IPMI SEL. 1. I disable auto reset when kernel panic by echo "0" > /proc/sys/kernel/panic 2. modprobe ipmi_watchdog timeout=120 action=reset 3. Load a driver, th