Kernel memory leak in ATAPI/CAM or ATAng?

Kevin Oberman oberman at
Thu Nov 6 08:08:35 PST 2003

I have learned a bit more about the problems I have been having with
the DVD drive on my T30 laptop. When I have run the drive for an
extended time (like 2 or 3 hours), I invariably have my system lock up
because it can't malloc kernel memory for the ATAPI/CAM or ATA
device. (Usually it's both.)

The only recovery seems to be to reboot the system.

I suspect a memory leak because it seems to be linked to total amount
of data transferred, even in multiple invocations of the program. Of
course, once the kernel grabs VM, I guess it generally does not
actually release it, but it should re-use the existing allocation and
not keep allocating more.

I posted my config and dmesg files yesterday. I have tried tuning
KVM_SIZE stuff with no real success, just the loss of the ability to
run with APM loaded. (This is possibly due to mis-tuning.)

Any ideas on where I can look for more information? I'm going to try
doing some monitoring with vmstat while running to see if I can spot
anything, but I am not sure just what I am looking for. The VM system
is not something I know much about, but I did read Terry Lambert's
excellent message to current on KVM tuning and I'm hoping that this
might help, but, if there really is a memory leak, tuning will not fix

FWIW, this problem did not exist a few month ago prior to ATAng.
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at			Phone: +1 510 486-8634

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