I would think that they are compatible. I'm using 2.6.24-rc4-mm1 and I dont get any output in dmesg regarding dynamic ticks being in use via the pmtmr like in old posts i've seen online. I was wondering if this output has been removed or if there is another way to determine if dynticks are active? I didn't notice any change in temperature when i was idle compared to previous kernel versions. hrtimers were detected and are in use correctly, cpu idle shows up in dmesg as being enabled and working (though i have no idea what menu and such governor means) nothing about dynticks though. my kernel cmd line doesn't contain anything that disables acpi or apic functions. In /proc/timer_list i do get this line .nohz_mode : 2 i haven't seen anything that describes what nohz modes are and what 2 means though. any heads up to some documentation on dynticks and cpuidle would be appreciated. All i could find on dynticks are just old announces on obscolete patches. the following is the contents of /proc/interrupts. The system is heavily loaded right now and has been for a day or so, so it isn't going to be helpful to see huge readings for idle clocks. CPU0 CPU1 0: 49 0 IO-APIC-edge timer 1: 0 2 IO-APIC-edge i8042 8: 0 0 IO-APIC-edge rtc 9: 0 0 IO-APIC-fasteoi acpi 12: 0 3 IO-APIC-edge i8042 14: 11 2932 IO-APIC-edge libata 15: 0 57 IO-APIC-edge libata 18: 15123 2083206 IO-APIC-fasteoi nvidia 20: 1513 190353 IO-APIC-fasteoi ohci_hcd:usb2 21: 0 3 IO-APIC-fasteoi ehci_hcd:usb1 22: 10117 979752 IO-APIC-fasteoi sata_nv 23: 89803 37633869 IO-APIC-fasteoi NVidia CK804, eth0 NMI: 0 0 Non-maskable interrupts LOC: 42644038 45872897 Local timer interrupts RES: 2093691 1302865 Rescheduling interrupts CAL: 487 62 function call interrupts TLB: 1546 1237 TLB shootdowns TRM: 0 0 Thermal event interrupts THR: 0 0 Threshold APIC interrupts SPU: 0 0 Spurious interrupts ERR: 0