odd audio failure

Nathan Field (nathan@Lanfear.ST.HMC.Edu)
Mon, 27 Oct 1997 19:24:19 -0800 (PST)

I'm getting an odd audio failure at random intervals. It seems to be
something to do with opening /dev/dsp. "strace mpg123 *.mp3 ; free" gave
me this:
[snip]
open("/dev/dsp", O_WRONLY) = -1 ENOMEM (Out of memory)
write(2, "Can\'t open /dev/dsp!\n", 21Can't open /dev/dsp!
) = 21
_exit(1) = ?
total used free shared buffers cached
Mem: 160384 147200 13184 30872 15168 89236
-/+ buffers: 42796 117588
Swap: 147160 268 146892

As you can see, I've got plenty of RAM free. I've found that if I use
chipmunk (a memory tester for linux) with some obscene amount of RAM
allocated (like 50MB), test for a bit and then quit chipmunk this happens:
running chipmunk with MEGS=50
total used free shared buffers cached
Mem: 160384 158208 2176 37220 5916 21488
right after killing chipmunk
total used free shared buffers cached
Mem: 160384 75376 85008 36848 5828 21260

And guess what, sound now works just fine! In a day or two (or less, I
haven't figured out when it does this) it will stop working again until I
suddenly free up large amounts of memory.

I'm running a 2.0.30 kernel, using an old SB 16 ISA which is not
Plug-and-Pray. If anyone needs more info than I've provided just let me
know and I'll be happy to help. Please cc me because sometimes I don't
have time to read the digest. Here are my config options for sound:

# Sound
CONFIG_SOUND=m
# CONFIG_PAS is not set
CONFIG_SB=y
CONFIG_ADLIB=y
# CONFIG_GUS is not set
# CONFIG_MPU401 is not set
# CONFIG_UART6850 is not set
# CONFIG_PSS is not set
# CONFIG_GUS16 is not set
# CONFIG_GUSMAX is not set
# CONFIG_MSS is not set
# CONFIG_SSCAPE is not set
# CONFIG_TRIX is not set
# CONFIG_MAD16 is not set
# CONFIG_CS4232 is not set
# CONFIG_MAUI is not set
CONFIG_AUDIO=y
CONFIG_MIDI=y
CONFIG_YM3812=y
SBC_BASE=220
SBC_IRQ=5
SBC_DMA=1
SB_DMA2=5
SB_MPU_BASE=0
SB_MPU_IRQ=-1
DSP_BUFFSIZE=65536
# CONFIG_LOWLEVEL_SOUND is not set

----------------------------
Nathan Field -- Activities: Consultant for CS Dept, building a Beowolf
machine for Math Dept. and passing my classes at Harvey
Mudd College in my free time.
For my PGP public key finger nathan@lanfear.st.hmc.edu