Re: emu10k1 - interrupt storm?

From: Zlatko Calusic (
Date: Tue Dec 11 2001 - 15:03:41 EST

Rui Sousa <> writes:

> On 9 Dec 2001, Zlatko Calusic wrote:
> The emu10k1 only generates interrupts when playing pcm sound.
> The interrupt rate depends on the "fragment" size and is usually
> smaller than ~1000interrupts/s (this is 256bytes fragment 48Khz sample
> rate, 16bit, stereo).
> Is it possible there is another device producing these interrupts?
> On-board devices (usb, ...) that you don't use?
> Does this happen with this kernel only?

Hm, looks like it is really emu10k1. But...

When I booted into single user mode, the kernel wasn't reporting
interrupts. Then I started Gnome, and there they were. Finally I found
that killing/starting esd changes things. Whenever esd was up,
interrupts were generated, when I killed it interrupts would stop.

Then I straced esd daemon, just to find it was blocked on select().

{atlas} [~]# strace -p 705
select(12, [4 6 7 8 9 10 11], NULL, NULL, NULL

Strange, if esd is not doing any work (just sleeping) who generates
interrupts then?

Also, we don't know now is it the driver to blame, or silly esd daemon.

> Which functions do you see listed? If it's only "emu10k1_interrupt()"
> then the interrupt was not generated by the emu10k1.

Top 5 entries in the kernel profile:

   475 __rdtsc_delay 16.9643
   309 handle_IRQ_event 2.4919
   178 do_softirq 0.8725
   148 emu10k1_waveout_bh 0.7872
   135 emu10k1_interrupt 0.6490

As time goes by, the numbers get bigger (that is only 15min after

Maybe it's time to enable debug option in the driver?

Sorry for late answer, I got busy yesterday...

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This archive was generated by hypermail 2b29 : Sat Dec 15 2001 - 21:00:21 EST