On Fri, May 17, 2019 at 04:06:20PM -0400, tedheadster wrote: > On Fri, May 17, 2019 at 2:15 PM Eduardo Habkost <ehabk...@redhat.com> wrote: > > Are you running the same kernel version on all VMs? > > X86_FEATURE_CPUID was added in Linux v4.11. > > > > Eduardo, > I am running a 4.9.162 virtual machine (very intentionally, the > drivers I need got broken in 4.11) inside of a 5.1.2 host.
That would explain why you don't see cpuid on /proc/cpuinfo. v4.9.162 doesn't have the flag. > > X86_FEATURE_CPUID is certainly defined in > arch/x86/kernel/cpu/capflags.c but nothing much seems to be done with > it. I don't see X86_FEATURE_CPUID in v4.9.162, which kernel source version are you looking at? > > The whole reason this came up is I was running 'perf top' on the > virtual host and it was spending the most kernel time calling cpuid(), > which seemed wrong. Which process was doing it? -- Eduardo
