show page size in /proc/$pid/numa_maps

Issue

• Implement the following in RHEL
  • [RFC][PATCH] show page size in /proc/$pid/numa_maps
  • Provides the ability to query the page size through /proc/$pid/numa_maps.
  • The 'bigfile' uses 1GB pages and takes up ~50GB of space.
  • The anon_hugepage uses 2MB pages and takes up ~100MB of space while the stack uses normal 4k pages.
  • You can go over to smaps to figure out what the page size really is with KernelPageSize or MMUPageSize however it is not efficient or intuitive.
  • The proposed patch adds a pagemult= field.
  • It is placed only in cases where the VMA's page size differs from the base kernel page size.
  • It is called pagemult to emphasize that it is indended to modify the statistics output rather than really show the page size that the kernel or MMU is using.