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by mochomocha 1663 days ago
In a setup with high-level of containers collocation on large ec2 instances, we've seen the opposite behavior at Netflix: default CFS performing badly. We've AB tested our flavor of custom pinning and measured substantial benefits: https://netflixtechblog.com/predictive-cpu-isolation-of-cont...

PMC data at scale is pretty clear: very often, CFS won't do the right thing and will leave bad HT neighbors on the same core, leading to L1 thrashing, or keep a high-level of imbalance between NUMA sockets leading to degraded LLC hit rate.

1 comments

Thanks, that's a very interesting case.

I correct my statement with "_did_ a good job", and appreciate rigorous testing.