4 Mar
2005
4 Mar
'05
10:59 a.m.
Spec wrote:
Seems that with RTIRQ another layer of virtual
interrupts is created,
great, but.... I reckon it might be better to put sound card ahead of
hard disk which is still on physical irq 14/15 where agp is on 16, sound
card is on 17 and onboard is on 23. (That combined with another disk
software layer added with LVM (not that LVM hasnt got its advantages...)
in FC3 slowing it down)
Anyone got any ideas how the set up of RTIRQ (if thats actually what is
doing it) virtual IRQ assignments is done?
only running on an XP1600+, trying to squeeze a bit more out of it...
48Khz low latency is pretty steady recording in ardour , but alsa_pcm
xruns at 96khz (happen about every 20 secs, seem to coincide with disk
access) particularly recording in ardour. Jack rack running multiple
effects at same 96khz 3.67ms latency is much more steady, roughly 1
dropout every 10 minutes, and thats with me messing around in the
background in gnome browsing, writing this etc.. (but not doing much HD
access...) in fact it seems so consistent that it may be some process
every 9.x mins causing this.
still thoroughly impressed though, 3ms latency stereo at 96kHz...
reliable enough to run jaaa .... and RT effects... Nice!
Are this about the rtirq (lowercase) script on planetccrma? I was the
original author of those bits and it is intended to generically prioritize
those IRQ thread handlers on a realtime-preemptible kernel (PREEMPT_RT).
If this makes sense to you, just check the output of the command:
/etc/init.d/rtirq status
and see how IRQ 14 and IRQ 15 is going among the others.
By default (see /etc/sysconfig/rtirq) the priority order is something like
this, from highest to lower:
rtc - real-time clock (usually IRQ 8)
snd - ALSA PCI sound modules (usually IRQ 5, 17 and/or 22 ...)
usb - USB host controllers (usually IRQ 10, 16, 18, 19 and/or 23 ...)
i8042 - keyboard/ps2-mouse controllers (usually IRQ 1 and/or 12 ...)
everything else must fall behind.
The original rtirq micro-tarball is attached: (rtirq-20041118.tar.gz). You
must have schedutils installed. If your system is not RPM based, so that
you can't use the provided .spec file, you have to do the installation by
hand, something in the likes of:
cp rtirq.sh /etc/init.d/rtirq
cp rtirq.conf /etc/sysconfig/rtirq
Hope it helps.
Cheers.
--
rncbc aka Rui Nuno Capela
rncbc(a)rncbc.org