Re: Soft Lockups on 2.6.28-rc8 under netperf bulk receive workload

Rick Jones
2008-12-17T19:44:09Z

Divy Le Ray wrote:
> Can you please reconfigure your kernel with the following kernel hacking
> options enabled, and run your tests again?
>
> Kernel hacking
> Kernel debugging
> Detect soft lockups
> RT mutex debugging
> Spinlock and rw-lock debugging: basic checks
> Mutex debugging: basic checks

Got the above

> Lock debugging: detect incorrect freeing of live locks
> Lock debugging: prove locking correctness

I don't see those two above in a make menuconfig

> Spinlock debugging: sleep-inside-spinlock checking
> Compile the kernel with debug info

Got those above.

> Compile the kernel with frame pointers

That doesn't appear in make menuconfig in kernel hacking either.

I built a kernel with those I could find enabled, and I think it invoked
the spirit of Heisenberg - no more soft lockups appearing on the
console. I think it has also _significantly_ dropped the throughput.

I've since learned how to tell caliper one doesn't care about the
per-process stuff and just lump it all together. The cycles and cgprof
profiles for the debug run can be found under the same URL as before:

ftp://ftp.netperf.org/lockup

with what I hope are obvious names.

rick jones