On Wed, Aug 15, Andi Kleen wrote:
Should we add the dwarf2 unwinder or not for 10.3?
Yes, I want to see it in 10.3.
Kernel oopses use approximate backtracing and also
report old left over garbage on the stack. In some
cases this can make oopses very hard to read.
Jan Beulich ported the NLKD dwarf2 unwinder to the kernel
to solve this problem.
It was merged to mainline, but due to some early teething
problems Linus drew it out. In the end it was relatively
I'm wondering if we should add it to the opensuse 10.3
- Better backtraces for kernel oopses. Saves developer
time which is very valuable.
- Would help testing it further
- Might still have bugs
(but in this case we fall back and should not lose any information)
- Increases kernel binary size in memory by ~10% for the unwind
IMHO the 10% more memory for unwind information is a good investment for
better backtraces. Since our distro isn't really optimized for small memory
footprint I don't think it hurts very much.
How long does a backtrace take compared to the old code? I see you already
care about the NMI. I guess it still takes too long for being called for
oprofiles callgraph backtrace? Are there any ways how we can speed this up?
To unsubscribe, e-mail: opensuse-kernel+unsubscribe(a)opensuse.org
For additional commands, e-mail: opensuse-kernel+help(a)opensuse.org