On Mon, Aug 10, 2020 at 02:24:21PM -0700, Kan Liang wrote: > Current perf can report both virtual addresses and physical addresses, > but not the page size. Without the page size information of the utilized > page, users cannot decide whether to promote/demote large pages to > optimize memory usage. > > Add a new sample type for the data page size. > > Current perf already has a facility to collect data virtual addresses. > A page walker is required to walk the pages tables and calculate the > page size from a given virtual address. > > On some platforms, e.g., X86, the page walker is invoked in an NMI > handler. So the page walker must be IRQ-safe and low overhead. Besides, > the page walker should work for both user and kernel virtual address. > The existing generic page walker, e.g., walk_page_range_novma(), is a > little bit complex and doesn't guarantee the IRQ-safe. The follow_page() > is only for user-virtual address.
s/IRQ/NMI/g
