On Monday 14 May 2007 21:22:50 Jan Engelhardt wrote: > On May 12 2007 22:12, Alistair John Strachan wrote: > >On Saturday 12 May 2007 00:07:18 Arjan van de Ven wrote: > >> What's eating the battery life of my laptop? Why isn't it many more > >> hours? Which software component causes the most power to be burned? > >> These are important questions without a good answer... until now. > > > >This is a really great tool and presents a very intuitive alternative to > > the timer stats file.. > > > >On a Core 2 Duo Macbook, Linux always gets around 3.2h battery, OS X about > >4.2h. This tool has identified that uhci_hcd is where 75% of the ticks are > >going when X is not loaded. Unloading uhci_hcd drops the battery life back > > to around 4.2h, but I lose the keyboard. > > > >Is there any way to find out what USB driver is causing usb_uhci to be > > this busy? > > At its worst, it _is_ the USB chip that draws the power when it is active > (when uhci_hcd is loaded); does not need to be usbhid or so. This is certainly true, and to a significant extent it _was_ the uhci_hcd, but it turns out the main contributor to HZ here were the appletouch and hci_usb drivers. Disabling both drops the ticks down from about 850 to 150. -- Cheers, Alistair. Final year Computer Science undergraduate. 1F2 55 South Clerk Street, Edinburgh, UK. - 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
