Lots of kernel wakeups in F11

[QuantumKnot]

Here is an excerpt from powertop

Top causes for wakeups:
69.2% (563.1) <kernel core> : hrtimer_start_range_ns (tick_sched_timer)
7.7% ( 62.5) <interrupt> : nvidia
4.9% ( 39.6) USB device 4-2 : Microsoft 3-Button Mouse with IntelliEye(TM)
4.9% ( 39.5) <interrupt> : uhci_hcd:usb4
3.4% ( 28.0) firefox : hrtimer_start_range_ns (hrtimer_wakeup)
1.7% ( 13.9) <kernel core> : hrtimer_start (tick_sched_timer)

Notice the kernel is generating an incredible number if interrupts (while surfing the web). Before, it used to be Rescheduling interrupts that was the culprit.

Anyone have this problem? Being on a laptop, it would be nice to get good battery life.

Using kernel 2.6.30.5-43.fc11.i686.PAE on Fedora 11 (32 bit)

[SlowJet]

Before what? The kernel is now tickless and only wakes up if something needs a kerenl action.
Fx, the mouse, usb, the video drv, yes, they need a lot of interupts for i/o, selinux, cpu.

Your battery life is not a kerenl problem, it is the workload running, mostly cpu demand at a higher step.
Fx alone would push the cpu to the max.

SJ

[QuantumKnot]

Well, I've noticed that every kernel since 2.6.24 has had issues with high wakeups even during low loads. I reported this before in Fedora 8

http://www.fedoraforum.org/forum/sho...d.php?t=183043

And bugzilla

https://bugzilla.redhat.com/show_bug.cgi?id=438974

While we don't see "Rescheduling interrupts" in powertop anymore, it seems this "hrtimer_start_range_ns" has taken its place, with lots of wakeups even during relatively idle periods.