lkml.org 
[lkml]   [2005]   [Jun]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] cpufreq: ondemand+conservative=condemand
On 6/27/05, Peter Chubb <peter@chubb.wattle.id.au> wrote:
> >>>>> "Paolo" == Paolo Marchetti <natryum@gmail.com> writes:
>
> >> Just change defaults in conservative governor to make it more
> >> responsive.
> >>
> Paolo> Alexey, I played with conservative governor trying to make it
> Paolo> work decently on my p4 with no results. As you know it works
> Paolo> but it isn't responsive, it takes eons to step up/down.
>
> You can always use a userspace governer. I've attached the one I use.
>
> Every five seconds (you can make it faster if you wish, but that seems
> about right for my usage patterns), the program reads the load
> average, and decides whether to adjust the CPU frequency. If the one
> second load average is above $FASTTRESHHOLD, the frequency will be
> stepped up by $FASTINC; otherwise if it's above $SLOWTHRESHHOLD, it's
> incremented by $SLOWINC. If the 15-second load average is below
> $DECTHRESSHOLD, the frequency is stepped downwards by $DEC. So you
> get fast increases, and slow decreases, but becasue the time constant
> for the decrease is long, you can get good response for a load spike,
> then fairly rapid decrease. The aim is to keep the load average
> around 0.9.
>
>
> --
> #!/bin/sh
>
> # Seconds to sleep between adjustments
> INTERVAL=5
>
> # The controller increments the throttling state by FASTINC
> # if the load average is over FASTTRHESHHOLD.
> # Thresholds are in percentage points load average -- i.e., the one
> # second load average of 1.0 corresponds to a threshold of 100.
> FASTINC=3
> FASTTHRESHOLD=100
> # Slow increment
> SLOWINC=1
> SLOWTHRESHOLD=80
> # Decrement
> DEC=1
> DECTHRESHOLD=500
>
> cd /sys/devices/system/cpu/cpu0/cpufreq
>
> # Do some parameter checks.
> [ $FASTTHRESHOLD -le $SLOWTHRESHOLD ] && {
> echo >&2 "Fast Threshold $FASTTHRESHOLD must be greater than the"
> echo >&2 "slow threshold $SLOWTHRESHOLD"
> exit 1
> }
>
> [ \( $SLOWINC -ge 1 \) -a \( $FASTINC -ge 1 \) -a \( $DEC -ge 1 \) ] || {
> echo >&2 "Increments must all be small integers in the range 1 to 7"
> exit 1
> }
>
> # convert a two dec place number to an int scaled by 100.
> function to_int()
> {
> val=$1
> OIFS="$IFS"
> IFS="."
> set $val
> IFS="$OIFS"
> expr $1 \* 100 + $2
> }
>
> # get load averages
> function loadavg()
> {
> read onesec fivesec fifteensec rest < /proc/loadavg
> onesec=`to_int $onesec`
> fifteensec=`to_int $fifteensec`
> }
>
> function getspeeds()
> {
> echo userspace > scaling_governor
> set `cat scaling_available_frequencies`
> i=0
> for j
> do
> i=`expr $i + 1`
> eval speed$i=$j
> done
> nspeeds=$i
> }
>
> # Get current throttling factor.
> # This can be changed automatically by the BIOS in response to power
> # events (e.g., AC coming on line).
> function throttle() {
> < scaling_cur_freq read curfreq
> i=1;
> while [ $i -lt $nspeeds ]
> do
> eval [ \$speed$i -eq 0$curfreq ] && expr $nspeeds - $i
> i=`expr $i + 1`
> done
> }
>
> function set_speed() {
> x=`expr $nspeeds - $1`
> eval speed=\$speed$x
> echo $speed > scaling_setspeed
> }
>
> # Increase the effective processor speed.
> function up()
> {
> [ $current_throttle -eq 0 ] || {
> current_throttle=`expr $current_throttle - $1`
> [ $current_throttle -lt 0 ] && current_throttle=0
> set_speed $current_throttle
> }
> }
>
> # Decrease the effective processor speed.
> function down()
> {
> [ $current_throttle -eq $nspeeds ] || {
> current_throttle=`expr $current_throttle + $1`
> [ $current_throttle -gt $nspeeds ] && current_throttle=$nspeeds
> set_speed $current_throttle
> }
> }
>
>
> getspeeds
> current_throttle=`throttle`
> while sleep $INTERVAL
> do
> loadavg
>
> # Go up fast, then tail off.
> #
> if [ $onesec -gt $FASTTHRESHOLD ]
> then
> up $FASTINC
> elif [ $onesec -gt $SLOWTHRESHOLD ]
> then
> up $SLOWINC
> elif [ $fifteensec -lt $DECTHRESHOLD ]
> then
> down $DEC
> fi
> done
>
Thank you, I'll try it.
Unfortunately the problem is: how to get conservative governor work
decently on a p4 laptop?
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-06-27 13:44    [W:0.048 / U:0.880 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site