Re: rcu stalls and soft lockups with recent kernels
From: Mike Galbraith
Date: Thu Mar 17 2016 - 22:29:13 EST
On Wed, 2016-03-16 at 12:15 -0400, Ion Badulescu wrote:
> Just following up to my own email:
> It turns out that we can eliminate the RCU stalls by changing from
> CONFIG_RCU_NOCB_CPU_ALL to CONFIG_RCU_NOCB_CPU_NONE. Letting each cpu
> handle its own RCU callbacks completely fixes the problems for us.
> Now, CONFIG_NO_HZ_FULL and CONFIG_RCU_NOCB_CPU_ALL is the default config
> for fedora and rhel7. Ho-humm...
All RCU offloaded to CPU0 of a big box seems like a very bad idea.