On Thu, 4 Oct 2018, Georgy Yakovlev wrote: ... > >Description: > After boot I noticed that on my TR2 220WX system kernel only uses > 8 cores out of 32 with hw.smt=0 > Not sure if it's correct. > According to my understanding if I set hw.smt=0 system should > see 32 cores, not 8.
hw.smt=0 disables all CPUs where the 'smt' topology value is nonzero. Per the dmesg you included, the smt values on the 64 CPUs range from 0 to 7, with eight having an smt value of zero. Now, perhaps the smt values returned by cpuid are misleading on this CPU: it appears that the combination of smt and core is unique _across_ packages: maybe we should instead enable the CPU with the lowest smt value for each package and core. Philip Guenther
