On Fri, 5 Aug 2005 01:03 am, Vojtech Pavlik wrote: > On Wed, Aug 03, 2005 at 04:23:59PM +0200, Jan De Luyck wrote: > > On Wednesday 03 August 2005 14:14, Con Kolivas wrote: > > > On Wed, 3 Aug 2005 21:54, Jan De Luyck wrote: > > > > On Wednesday 03 August 2005 07:59, Con Kolivas wrote: > > > > > This is the dynamic ticks patch for i386 as written by Tony Lindgen > > > > > <[EMAIL PROTECTED]> and Tuukka Tikkanen > > > > > <[EMAIL PROTECTED]>. Patch for 2.6.13-rc5 > > > > > > > > Compiles and runs ok here. > > > > > > > > Is there actually any timer frequency that's advisable to set as > > > > maximum? (in the kernel config) > > > > > > I'd recommend 1000. > > > > Thanks. Currently the system - under X, KDE, no artsd, bottoms at around > > 300HZ. In total single mode with every module unloaded that I can unload > > it stops around 22HZ. > > > > I guess I'll have to go hunting whatever thing is causing the pollings. > > no timertop yet, I guess? :P > > i8042 runs a steady periodic 20Hz timer. You can make it slower to get > even the total low lower, and it will not affect performance under > normal (sane hardware) circumstances.
Indeed and this patch (safely tried at home but serves no useful purpose really) confirms a reasonable drop without problems. After this, only fbcon polls at a similar rate (HZ/5). Of interest to those using an ondemand scaling governor, now that we have timertop, I have found that the default ondemand settings lead to delayed_work_timer_fn at about 140Hz and this can be dropped substantially by slowing the rate of polling (and subsequently slowing the speed with which the ondemand governor responds) down to <25 by echo 100000 > /sys/devices/system/cpu/cpu0/cpufreq/ondemand/sampling_rate (the default is 10000 and the value is confusing as the rate goes down as you increase this value). Cheers, Con
Index: linux-2.6.13-rc5-ck2/drivers/input/serio/i8042.h =================================================================== --- linux-2.6.13-rc5-ck2.orig/drivers/input/serio/i8042.h 2005-07-06 16:56:52.000000000 +1000 +++ linux-2.6.13-rc5-ck2/drivers/input/serio/i8042.h 2005-08-05 15:03:49.000000000 +1000 @@ -44,7 +44,7 @@ * polling. */ -#define I8042_POLL_PERIOD HZ/20 +#define I8042_POLL_PERIOD HZ/5 /* * Status register bits.
