On Wed, Jun 03, 2020 at 06:56:57AM +0530, Anshuman Khandual wrote: > On 06/02/2020 08:31 PM, Matthew Wilcox wrote: > > On Fri, May 22, 2020 at 09:04:04AM +0530, Anshuman Khandual wrote: > >> This adds the following two new VM events which will help in validating PMD > >> based THP migration without split. Statistics reported through these events > >> will help in performance debugging. > >> > >> 1. THP_PMD_MIGRATION_SUCCESS > >> 2. THP_PMD_MIGRATION_FAILURE > > > > There's nothing actually PMD specific about these events, is there? > > If we have a THP of a non-PMD size, you'd want that reported through the > > same statistic, wouldn't you? > > Yes, there is nothing PMD specific here and we would use the same statistics > for non-PMD size THP migration (if any) as well. But is THP migration really > supported for non-PMD sizes ? CONFIG_ARCH_ENABLE_THP_MIGRATION depends upon > CONFIG_TRANSPARENT_HUGEPAGE without being specific or denying about possible > PUD level support. Fair enough, will drop the PMD from the events and their > functions. I guess you haven't read my large pages patchset?