Hello,
I use FreeBSD STABLE on Acer Aspire 1525, with VIA K8M400 chipset and
VIA1612A on-motherboard sound card.
I've beet tracing STABLE from some time ago, and at some point of 5.X
series my sound started to be distorted (clicks, lags, metallic sounds)
in a random manner, with distortions correlated with network/disk activity.
(This was reported before -- kern/81599, and some posts here and there)
After setting hint.pcm.0.buffersize to a bigger value and applying
patches from http://people.freebsd.org/~ariff/ (BTW: contrary to the
message there, these don't seem to be MFC'ed (?)) the sound distortions
were completely simultaneous with network activity. Neither CPU load
(and acpi_perf changing the cpu speed) nor high disk i/o (unpacking
sources, making /usr/libexec/locate.updatedb) affected the sound, but
only as I entered IRC or openned some pages in a browser I did hear
clicks and lags.
Apparently the reason was pcm0 and re0 (Ethernet card) sharing one irq.
By setting a different IRQ for some of devices in BIOS and turning off
APIC, I got a new irq layout which gives pcm0 an exclusive IRQ.
I rejoiced, because the sound is perfect now.
However, I have few questions:
1) Is turning off APIC a disadvantage? (I have read the wikipedia page
on IO-APIC and I the machine is uniprocessor)
Will it bring my performance down? Or do other scary things to me?
Maybe there is a better way to force different IRQ layout.
2) vmstat -i now shows:
interrupt total rate
irq0: clk 6824889 968
irq1: atkbd0 13103 1
irq4: sio0 2 0
irq7: ppc0 71 0
irq8: rtc 890176 126
irq9: nvidia0 cbb* 464262 65
irq10: cbb0 uhci1* 3 0
irq11: ndis0 re0+ 130633 18
irq12: psm0 597273 84
irq14: ata0 118892 16
irq15: ata1 74 0
Total 9039378 1283
Does it look normal? What do '*' and '+' after device names
mean?
I couldn't find this information in man vmstat, google or even quich
grep through vmstat.c. What am I missing?
Is there something to be worried about this?
Thank's for Your time and sorry for crossposting to -multimedia@ (some
people searching it might (?) find this post helpful).
Regards,
m.