Re: Oops in 2.6.19.1

On Thursday 28 December 2006 04:14, Alistair John Strachan wrote:
On Thursday 28 December 2006 04:02, Alistair John Strachan wrote:
On Thursday 28 December 2006 02:41, Zhang, Yanmin wrote:
[snip]

Here's a current decompilation of vmlinux/pipe_poll() from the
running kernel, the addresses have changed slightly. There's no xchg
there either:

Could you reproduce the bug by the new kernel, so we could get the
exact address and instruction of the bug?

It crashed again, but this time with no output (machine locked solid). To
be honest, the disassembly looks right (it's like Chuck said, it's
jumping back half way through an instruction):

c0156f5f: 3b 87 68 01 00 00 cmp 0x168(%edi),%eax

So c0156f60 is 87 68 01 00 00..

This is with the GCC recompile, so it's not a distro problem. It could
still either be GCC 4.x, or a 2.6.19.1 specific bug, but it's serious.
2.6.19 with GCC 3.4.3 is 100% stable.

Looks like a similar crash here:

http://ubuntuforums.org/showthread.php?p=1803389

I've eliminated 2.6.19.1 as the culprit, and also tried toggling "optimize for
size", various debug options. 2.6.19 compiled with GCC 4.1.1 on an Via
Nehemiah C3-2 seems to crash in pipe_poll reliably, within approximately 12
hours.

The machine passes 6 hours of Prime95 (a CPU stability tester), four memtest86
passes, and there are no heat problems.

I have compiled GCC 3.4.6 and compiled 2.6.19 with an identical config using
this compiler (but the same binutils), and will report back if it crashes. My
bet is that it won't, however.

--
Cheers,
Alistair.

Final year Computer Science undergraduate.
1F2 55 South Clerk Street, Edinburgh, UK.
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