Re: [PATCH 09/10] sched/fair: disable stealing if too many NUMA nodes

[Steven Sistare]

On 10/22/2018 1:06 PM, Peter Zijlstra wrote:
> On Mon, Oct 22, 2018 at 07:59:40AM -0700, Steve Sistare wrote:
>> The STEAL feature causes regressions on hackbench on larger NUMA systems,
>> so disable it on systems with more than sched_steal_node_limit nodes
>> (default 2).
> 
> How come? From a quick read the stealing is per LLC, where do we steal
> across nodes?

See the complete explanation in this patch.  It is deeper than can be gleaned
from a quick read.

- Steve