Re[2]: 3.17: bcache_gc: BUG: soft lockup - CPU#2 stuck for 22s!

Pavel Goran
2014-10-31T10:35:17Z

Hello Zhu,

Friday, October 31, 2014, 3:20:32 PM, you wrote:

> Theoretically this livelock does exist all the way, however we can't
> reproduce it on 3.17 kernel, or maybe it's just because the stress is
> not big enough. Anyway it can be reproduced easily on RHEL6 kernel (we
> have ported bcache back to the RHEL6 kernel). Dunno if it's caused by
> the differences between the schedulers.

My experience shows that scheduler can be a factor here. I regularly had the
lockup issue while running a kernel with BFS scheduler (pf-kernel). Then I
switched to CFS and lockups disappeared. (Now I'm running 3.17 with BFS and
with the October 18 patch from the mailing list, no issues as of yet.)

Pavel Goran