Larry Finger<Larry.Finger@xxxxxxxxxxxx> writes:
On 05/01/2011 12:59 PM, Shawn Nock wrote:During heavy network traffic (esp. flash video) I see the attached
NULL pointer dereference in 2.6.39-rc5 on an IBM Thinkpad
x120e. Immediately afterward a "scheduling while atomic" bug is
reported and the system becomes unresponsive. I am unable to produce
this problem in 2.6.38.4.
See attached backtrace and dmesg. Please let me know what I can
collect to make this problem easier to troubleshoot.
Could you also supply the instruction byte sequence for the oops? It
is the "Code:" line of the dump.
I had not been able to capture that, as the scheduler oops was triggered
during the call stack dump (before the Code line).
I think you are using a 32-bit system. Is that correct?
Correct.
Is there one URL that exposes this problem? If so, please sent that as
well.
It had been speedtest.net (which *used* to crash this all the
time). I've since re-configured the kernel to allow it to build faster
(fedora .config trimmed to remove a lot of the unneeded modules). I can
no longer trigger this BUG.
I originally thought that this may be because I enabled the 8192CU
driver, but clean kernel without it also doesn't trigger the bug. My new
hypothesis is that building the kernel for the AMD processor type was a
mistake (the only other significant change was that I went back to
Pentium Pro as the CPU target).
As far as I can tell this problem is resolved (20+ hours without issue,
less than 20 min previously) and probably due to GCC not being aware of
this (newish) AMD processor.
Sorry for the false alarm and thanks,