It seems sensible the more CPU we get in the cluster, the more we need the kernel to be aware of its existence.
Tim, it is possible for you to bring up the cpu_cluster_mask and cluster_sibling for x86 so that the topology can be represented in sysfs and be used by scheduler? It seems your patch lacks this part.
You mean having something in /sys/devices/system/cpu/cpu0/topology on cluster information so that an external program can affinitize to a cluster if it prefers to do so?
Tim
BTW, I wonder if x86 can do some improvement on your KMP_AFFINITY by leveraging the cluster topology level. https://software.intel.com/content/www/us/en/develop/documentation/cpp-compi...
KMP_AFFINITY has thread affinity modes like compact and scatter, it seems this "compact" and "scatter" can also use the cluster information as you see we are also struggling with the "compact" and "scatter" issues here in this patchset :-)
Thanks Barry