device driver memory leak in 5.1-20030726?

[Gary Jennejohn]

Lukas Ertl writes:
> On Sun, 27 Jul 2003, Mark Blackman wrote:
> 
> > Perhaps it's a USB bug. There seems to be some correspondence between
> > the use of the USB Speedtouch ADSL modem and the out-of-control
> > devbuf allocations.
> 
> I'm too seeing these annoying kmem_malloc panics on recent -current
> kernels. The laptop I'm using is way off of being overloaded at all, the
> only thing I do is going online using a Bluetooth USB dongle. As soon as I
> generate some network traffic, devbuf allocations go up, until at some
> point the machine panics randomly in kmem_malloc.
> 
> I have different core dumps and backtraces available, but they don't seem
> to be of much use in this case. I really suspect the USB stuff to be
> leaking.
> 

I did some playing around today with various kernels.

A kernel from July 12 at 12:01 works just fine.

A kernel from July 15 at 23:30 hangs (with the IRQ9 thread and g_down
each using 50% of the CPU). Killing the mount with ^C leaves the (in
my case) mount_msdos hung in the background and it's un-killable.
It's probably stuck waiting for USB.

A kernel from July 16 at 12:01 exhibits similar symptoms to the
kernel from July 15.

July 15 is about the time that a massive update of the USB code from
NetBSD was made.

I didn't try kernels from July 13 or July 14.

I've observed other problems with -current:
1) mount_msdos results in a kernel panic (NULL pointer deref)
2) mounting linuxprocfs also results in a panic

At the moment I'm running a world from July 15 and a kernel from July 12.

---
Gary Jennejohn / garyj[at]jennejohn.org gj[at]freebsd.org gj[at]denx.de