kernel test robot <oliver.sang@xxxxxxxxx> writes: > Greeting, > > FYI, we noticed a -53.8% regression of stress-ng.memhotplug.ops_per_sec due to commit: > > > commit: 9eeb73028cfb54eb06efe87c50cc014d3f1ff43e ("[patch 174/212] mm/migrate: update node demotion order on hotplug events") > url: https://github.com/0day-ci/linux/commits/Andrew-Morton/ia64-fix-typo-in-a-comment/20210903-065028 > > > in testcase: stress-ng > on test machine: 96 threads 2 sockets Intel(R) Xeon(R) Gold 6252 CPU @ 2.10GHz with 192G memory > with following parameters: > > nr_threads: 10% > disk: 1HDD > testtime: 60s > fs: ext4 > class: os > test: memhotplug > cpufreq_governor: performance > ucode: 0x5003006 > Because we added some operations during online/offline CPU, it's expected that the performance of online/offline CPU will decrease. In most cases, the performance of CPU hotplug isn't a big problem. But then I remembers that the performance of the CPU hotplug may influence suspend/resume performance :-( It appears that it is easy and reasonable to enclose the added operations inside #ifdef CONFIG_NUMA. Is this sufficient to restore the performance of suspend/resume? Best Regards, Huang, Ying