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.
