On Thu, Jun 7, 2018 at 10:06 AM Chang S. Bae <chang.seok....@intel.com> wrote: > > The CPU (and node) number will be written, as early enough, > to the segment limit of per CPU data and TSC_AUX MSR entry. > The information has been retrieved by vgetcpu in user space > and will be also loaded from the paranoid entry, when > FSGSBASE enabled. > > Now storing CPU number to the CPU_NUMBER segment limit is > done during the bootstrap, while MSR TSC_AUX is written > during each CPU initialization that is still before IST > setup. > > The redundant setting of the segment in entry/vdso/vma.c > was removed; a substantial code removal. It removes a > hotplug notifier, makes a facility useful to both the kernel > and userspace unconditionally available much sooner. > (Thanks to HPA for suggesting the cleanup)
Couldn't setup_cpu_number_segment()'s contents go in setup_cpu_number()? --Andy
