>-----Original Message----- >From: [EMAIL PROTECTED] >[mailto:[EMAIL PROTECTED] On Behalf Of >[EMAIL PROTECTED] >Sent: Wednesday, February 20, 2008 11:01 PM >To: linux-kernel@vger.kernel.org >Cc: Song, Youquan >Subject: 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-2.6.18 the CPU C state information is normal. > > >Every 0.1s: cat /proc/acpi/processor/CPU*/power | grep 'active >state' > > >Thu Feb 21 09:44:33 2008 > >active state: C0 >active state: C0 >active state: C0 >active state: C0 >active state: C0 >active state: C0 >active state: C0 >active state: C0 > >On RHEL5.1 kernel-2.6.18-53.el5 >[EMAIL PROTECTED] ~]# cat /proc/acpi/processor/CPU*/power | grep >'active state' >active state: C2 >active state: C2 >active state: C2 >active state: C2 >active state: C2 >active state: C3 >active state: C2 >active state: C3 > >The hardware platform: bensley and santarosa. >
I am not sure active state gives a lot of information about C-state. And I really hate to see code waking up every .1 sec to check the active state :-). /proc/acpi/processor/*/power is marked deprecated upstream and if you really want this field, you will have to disable CONFIG_CPU_IDLE in upstream kernel. With CPU_IDLE you will get more detailed information about all C-states entry counts and residencies under /sys/devices/system/cpu/cpu*/cpuidle/ Thanks, Venki -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
