Messages in this thread | | | Date | Mon, 5 Apr 2010 22:41:43 +0200 | From | Dominik Brodowski <> | Subject | Re: A few questions and issues with dynticks, NOHZ and powertop |
| |
On Sun, Apr 04, 2010 at 08:42:43PM -0700, Arjan van de Ven wrote: > On 4/4/2010 3:47, Dominik Brodowski wrote: > >Hey, > > > >On Sat, Apr 03, 2010 at 04:53:26PM -0700, Dmitry Torokhov wrote: > >>On Sun, Apr 04, 2010 at 12:33:28AM +0200, Dominik Brodowski wrote: > >>> > >>>4) SynPS/2 touchpad: > >>>Why does moving the touchpad lead to sooo many IRQs? I can't look as fast > >>>as the mouse pointer seems to get new data: > >>> 62,5% (473,1)<interrupt> : PS/2 keyboard/mouse/touchpad > >>> > >> > >>80 pps @ 6 bytes/packet = 480 interrupts/sec. > >> > >>You can try using psmouse.rate=40 to limit it to 40 pps which should > >>bring it to the rate of standard PS/2 mouse at the expense of > >>sensitivity... > > > >as a sidenote: if we know -- like here -- that the next IRQ will be issued > >soon, in approximately 1.75 ms (well, at least on my system), might it make > >sense to make tick_nohz_get_sleep_length() smarter to know about this? > > yes and no. > > if you are very sure (95%+ or so) then absolutely it needs to know about this > so that the C state selection code can make a better decision. > Right now it tries to look at history to guess this delay. > > Unfortunately we do not currently have such a concept in the code to make this > work... but it'd be really nice to have.
Dmitry, are we "very sure" in this touchpad case?
Best, Dominik
| |