17 Dec
2008
17 Dec
'08
5:26 p.m.
"God does not play dice" said Einstein, but the assignment of IRQ's at
boot surely seems to be a bit of a random game (which only proves that
Linus isn't God, I suppose ...)
I would like to automagically increase the priority of the IRQ
associated with my soundcard - peek at "the dice" before placing my bet
so to say - how do I do that?
I used to have:
chrt -f -p 80 `pidof IRQ-20`
.. in rc.local, but sometimes the relevant IRQ changes to 19 (giving
IRQ-20 to something else), which may or may not cause a hanging system.
from (todays) /proc/interrupts:
[...]
19: 49 0 IO-APIC-fasteoi ehci_hcd:usb1,
uhci_hcd:usb2
20: 8416716 0 IO-APIC-fasteoi firewire_ohci, HDA Intel,
uhci_hcd:usb5
18 Dec
18 Dec
5:10 p.m.
2008/12/17 Jens M Andreasen <jens.andreasen(a)comhem.se>se>:
I would like to automagically increase the priority of
the IRQ
associated with my soundcard - peek at "the dice" before placing my bet
so to say - how do I do that?
Mr Rui Nuno Capela figured this out for you/us:
http://alsa.opensrc.org/Rtirq
Not sure why, but rtirq is hard to be found on the internet, these
days. The Gentoo-proaudio people have packaged it here:
http://download.tuxfamily.org/proaudio/distfiles/rtirq-20071012.tar.gz
Or see the main shell script below; the line you want goes like this:
grep irq /proc/asound/cards | tac | sed 's/.* irq \(.*\)/\1/'
Kind regards.
### ### ### ### ### ### ###
cat /etc/init.d/rtirq.sh
#!/bin/bash +x
#
# Copyright (c) 2004-2007 rncbc aka Rui Nuno Capela.
#
# /etc/init.d/rtirq
#
# Startup script for realtime-preempt enabled kernels.
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License version 2 or later.
#
# chkconfig: 35 81 19
# description: Realtime IRQ thread tunning.
#
### BEGIN INIT INFO
# Provides: rtirq
# Required-Start: $syslog $local_fs
# Should-Start: $time alsa alsasound hotplug
# Required-Stop: $syslog $local_fs
# Should-Stop: $time alsa alsasound hotplug
# Default-Start: 3 5
# Default-Stop: 0 1 2 6
# Short-Description: Realtime IRQ thread tunning.
# Description: Change the realtime scheduling policy
# and priority of relevant system driver IRQ handlers.
### END INIT INFO
#
# Won't work without those binaries.
for DIR in /sbin /usr/sbin /bin /usr/bin /usr/local/bin; do
[ -z "${RTIRQ_CHRT}" -a -x ${DIR}/chrt ] &&
RTIRQ_CHRT=${DIR}/chrt
done
# Check for missing binaries (stale symlinks should not happen)
[ -n "${RTIRQ_CHRT}" -a -x ${RTIRQ_CHRT} ] || {
echo "`basename $0`: chrt: not installed."
[ "$1" = "stop" ] && exit 0 || exit 5
}
# Check for existence of needed config file and read it.
RTIRQ_CONFIG=/etc/conf.d/rtirq
[ -r ${RTIRQ_CONFIG} ] || RTIRQ_CONFIG=/etc/default/rtirq
[ -r ${RTIRQ_CONFIG} ] || RTIRQ_CONFIG=/etc/rtirq.conf
[ -r ${RTIRQ_CONFIG} ] || {
echo "`basename $0`: ${RTIRQ_CONFIG}: not found."
[ "${RTIRQ_ACTION}" = "stop" ] && exit 0 || exit 6
}
# Read configuration.
source ${RTIRQ_CONFIG}
# Colon delimited trail list of already assigned IRQ numbers,
# preventind lower priority override due to shared IRQs.
RTIRQ_TRAIL=":"
#
# Reset policy of all IRQ threads out there.
#
function rtirq_reset ()
{
# Reset all softirq-timer/s from highest priority.
rtirq_exec_high reset
# PIDS=`ps -eo pid,class | egrep '(FF|RR)' | awk '{print $1}'`
PIDS=`ps -eo pid,comm | grep IRQ | awk '{print $1}'`
for PID in ${PIDS}
do
${RTIRQ_CHRT} --pid --other 0 ${PID}
done
}
#
# IRQ thread handler policy prioritizer, by IRQ number.
#
function rtirq_exec_num ()
{
ACTION=$1
NAME1=$2
NAME2=$3
PRI2=$4
IRQ=$5
# Check the services that are to be (un)threaded.
if [ -n "`echo :${RTIRQ_NON_THREADED}: | sed 's/ /:/g' | grep
:${NAME1}:`" ]
then
PREPEND="`basename $0`: ${ACTION} [${NAME2}] irq=${IRQ}"
for THREADED in /proc/irq/${IRQ}/*/threaded
do
if [ -f "${THREADED}" ]
then
case ${ACTION} in
*start)
echo "${PREPEND}: ${THREADED}: OFF."
echo -n 0 > "${THREADED}"
;;
stop)
echo "${PREPEND}: ${THREADED}: ON."
echo -n 1 > "${THREADED}"
;;
esac
fi
done
fi
# And now do the proper threading prioritization...
if [ -z "`echo ${RTIRQ_TRAIL} | grep :${IRQ}:`" ]
then
PIDS=`ps -eo pid,comm | egrep "IRQ.${IRQ}\$" | awk '{print
$1}'`
for PID in ${PIDS}
do
PREPEND="`basename $0`: ${ACTION} [${NAME2}]
irq=${IRQ} pid=${PID}"
case ${ACTION} in
*start)
PREPEND="${PREPEND} prio=${PRI2}"
if ${RTIRQ_CHRT} --pid --fifo ${PRI2} ${PID}
then
echo "${PREPEND}: OK."
else
echo "${PREPEND}: FAILED."
fi
;;
stop)
if ${RTIRQ_CHRT} --pid --other 0 ${PID}
then
echo "${PREPEND}: OK."
else
echo "${PREPEND}: FAILED."
fi
;;
status)
echo "${PREPEND}: " && ${RTIRQ_CHRT}
--pid --verbose ${PID}
;;
*)
echo "${PREPEND}: ERROR."
;;
esac
PRI2=$((${PRI2} - 1))
done
RTIRQ_TRAIL=":${IRQ}${RTIRQ_TRAIL}"
fi
}
#
# IRQ thread handler policy prioritizer, by service name.
#
function rtirq_exec_name ()
{
ACTION=$1
NAME1=$2
NAME2=$3
PRI1=$4
IRQS=`grep "${NAME2}" /proc/interrupts | awk -F: '{print $1}'`
for IRQ in ${IRQS}
do
rtirq_exec_num ${ACTION} ${NAME1} ${NAME2} ${PRI1} ${IRQ}
PRI1=$((${PRI1} - 1))
done
}
#
# Generic process top prioritizer
#
function rtirq_exec_high ()
{
ACTION=$1
case ${ACTION} in
*start)
PRI1=99
;;
*)
PRI1=1
;;
esac
# Process all configured process names...
for NAME in ${RTIRQ_HIGH_LIST}
do
PREPEND="`basename $0`: ${ACTION} [${NAME}]"
PIDS=`ps -eo pid,comm | grep "${NAME}" | awk '{print
$1}'`
for PID in ${PIDS}
do
if ${RTIRQ_CHRT} --pid --fifo ${PRI1} ${PID}
then
echo "${PREPEND} pid=${PID} prio=${PRI1}: OK."
else
echo "${PREPEND} pid=${PID}
prio=${PRI1}: FAILED."
fi
done
[ ${PRI1} -gt ${RTIRQ_PRIO_HIGH} ] && PRI1=$((${PRI1} - 1))
done
}
#
# Main executive.
#
function rtirq_exec ()
{
ACTION=$1
# Check configured base priority.
PRI0=${RTIRQ_PRIO_HIGH:-90}
[ $((${PRI0})) -gt 95 ] && PRI0=95
[ $((${PRI0})) -lt 55 ] && PRI0=55
# Check configured priority decrease step.
DECR=${RTIRQ_PRIO_DECR:-5}
[ $((${DECR})) -gt 10 ] && DECR=10
[ $((${DECR})) -lt 1 ] && DECR=1
# (Re)set all softirq-timer/s to highest priority.
rtirq_exec_high ${ACTION}
# Process all configured service names...
for NAME in ${RTIRQ_NAME_LIST}
do
case ${NAME} in
snd)
PRI1=${PRI0}
IRQS=`grep irq /proc/asound/cards | tac | sed
's/.* irq \(.*\)/\1/'`
for IRQ in ${IRQS}
do
rtirq_exec_num ${ACTION} ${NAME}
${NAME} ${PRI1} ${IRQ}
PRI1=$((${PRI1} - 1))
done
;;
usb)
rtirq_exec_name ${ACTION} ${NAME} "ohci_hcd" ${PRI0}
rtirq_exec_name ${ACTION} ${NAME} "uhci_hcd" ${PRI0}
rtirq_exec_name ${ACTION} ${NAME} "ehci_hcd" ${PRI0}
;;
*)
rtirq_exec_name ${ACTION} ${NAME} ${NAME} ${PRI0}
;;
esac
[ ${PRI0} -gt ${DECR} ] && PRI0=$((${PRI0} - ${DECR}))
done
}
#
# Main procedure line.
#
case $1 in
*start)
if [ "${RTIRQ_RESET_ALL}" = "yes" -o
"${RTIRQ_RESET_ALL}" = "1" ]
then
rtirq_reset
fi
rtirq_exec start
;;
stop)
if [ "${RTIRQ_RESET_ALL}" = "yes" -o
"${RTIRQ_RESET_ALL}" = "1" ]
then
rtirq_reset
#else
# rtirq_exec stop
fi
;;
reset)
if [ "${RTIRQ_RESET_ALL}" = "yes" -o
"${RTIRQ_RESET_ALL}" = "1" ]
then
rtirq_reset
else
rtirq_exec stop
fi
;;
status)
echo
#rtirq_exec status
ps -eo pid,class,rtprio,ni,pri,pcpu,stat,comm --sort -rtprio \
| egrep '(^[[:blank:]]*PID|IRQ|s(oft)?irq)' \
| awk 'BEGIN {
while (getline IRQLine < "/proc/interrupts") {
split(IRQLine, IRQSplit, ":[[:blank:]|0-9]+");
if (match(IRQSplit[1],
"^[[:blank:]]*[0-9]+$")) {
gsub("[^[:blank:]]+PIC[^[:blank:]]*[[:blank:]]+" \
"|\\[[^\\]]+\\][^[:blank:]]*[[:blank:]]+",
"", IRQSplit[2]);
IRQTable[IRQSplit[1] + 0] = IRQSplit[2];
}
}
} { if ($9 == "")
{ print $0"\t"IRQTable[substr($8,5)]; }
else
{ print $0"\t"IRQTable[$9]; } }'
echo
;;
*)
echo
echo " Usage: $0 {[re]start|stop|reset|status}"
echo
exit 1
;;
esac
exit 0
7:41 p.m.
On Thu, 2008-12-18 at 22:09 +0100, Jean-Baptiste Mestelan wrote:
Not sure why, but rtirq is hard to be found on the
internet, these
days. The Gentoo-proaudio people have packaged it here:
http://download.tuxfamily.org/proaudio/distfiles/rtirq-20071012.tar.gz
Or see the main shell script below; the line you want goes like this:
grep irq /proc/asound/cards | tac | sed 's/.* irq
\(.*\)/\1/'
Thanks!
BTW: Do you have any idea what the rationale behind that 'tac' in the
middle is?
19 Dec
19 Dec
5:39 p.m.
2008/12/19 Jens M Andreasen <jens.andreasen(a)comhem.se>se>:
Not really; but, by chance (?), this gives acceptable results on my machine:
# cat /proc/asound/cards
0 [Intel ]: HDA-Intel - HDA Intel
HDA Intel at 0xf5100000 irq 21
1 [M44 ]: ICE1712 - M Audio Delta 44
M Audio Delta 44 at 0xb000, irq 23
# htop (mmh, how do I copy/paste a curses screen ??)
=> IRQ-23 gets to run with PRI=-86
=> IRQ-21 gets to run with PRI=-85
So, the Delta 44 gets privilege over the HDA Intel, which is what I
expect, as the latter only gets used for media playback (Firefox,
Mplayer and such).
Come to think of it, and as IRQ numbers *do* vary on boot, I am not
quite sure if this would be the case for every run ?
Also, I do not suppose that both soundcards could ever conflict, as I
generally do not listen to Flash videos on one card while doing
serious audio work on the other ?
grep irq
/proc/asound/cards | tac | sed 's/.* irq \(.*\)/\1/'
BTW: Do you have any idea what the rationale behind that 'tac' in the
middle is?
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3 comments
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Jean-Baptiste Mestelan -
Jens M Andreasen