Re: QUESTION: Network hangs with BP6 and 2.4.x kernels, hardware

Frank de Lange
2001-01-13T01:28:28Z

On Fri, Jan 12, 2001 at 04:56:24PM -0800, Linus Torvalds wrote:
> IDE is not my favourite example of a "known stable driver". Also, in many
> cases IDE is for historical reasons connected to an EDGE io-apic pin (ie
> it's still considered an ISA interrupt). Which probably wouldn't show this
> problem anyway.

They (ide interrupts) are indeed EDGE-triggered on my box. I have not enabled
the HPT366 (ATA66) controller on this board, so I can not tell if that
controller is EDGE-triggered as well.

> Also, IDE doesn't generate all that many interrupts. You can make a
> network driver do a _lot_ more interrupts than just about any disk driver
> by simply sending/receiving a lot of packets. With disks it is very hard
> to get the same kind of irq load - Linux will merge the requests and do at
> least 1kB worth of transfer per interrupt etc. On a ne2k 100Mbps PCI card,
> you can probably _easily_ generate a much higher stream of interrupts.

There's sound... The msnd.c (Turtle Beach MultiSound) driver (and its
derivatives, like msnd_pinnacle) uses disable_irq. Running esd (esound
daemon), sound can easily generate > 1000 interrupts/second, since esd uses
small dma transfers. This can be seen quite clearly from /proc/interrupts on my
soundserver:

CPU0
0: 276867328 XT-PIC timer
1: 2 XT-PIC keyboard
2: 0 XT-PIC cascade
3: 7631519 XT-PIC eth1
4: 2751419 XT-PIC serial
5: 1907346678 XT-PIC soundblaster
8: 1 XT-PIC rtc
9: 45022986 XT-PIC eth0
13: 1 XT-PIC fpu
14: 4320643 XT-PIC ide0
15: 4409193 XT-PIC ide1
NMI: 0

OK, this is an ageing P166, and it uses a different driver, etc. I have not
found any problems with hanging sound drivers in Google query for 'linux msnd
bp6' or 'linux multisound bp6'. Of course, this is no conclusive evidence, far
from it... It could be that people using those cards are not the ones who tend
to go for the (somewhat tricky) BP6 board...

Cheers//Frank

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