On Tue, 7 Jul 2020 05:36:55 +0530 Anshuman Khandual <[email protected]> wrote:
> Add following new vmstat events which will help in validating THP migration > without split. Statistics reported through these new VM events will help in > performance debugging. > > 1. THP_MIGRATION_SUCCESS > 2. THP_MIGRATION_FAILURE > 3. THP_MIGRATION_SPLIT > > In addition, these new events also update normal page migration statistics > appropriately via PGMIGRATE_SUCCESS and PGMIGRATE_FAILURE. While here, this > updates current trace event 'mm_migrate_pages' to accommodate now available > THP statistics. Patch looks straightforward enough. It would be nice to see some confirmation from others that these metrics are a desirable thing to export. > ... > > - trace_mm_migrate_pages(nr_succeeded, nr_failed, mode, reason); > + if (nr_thp_succeeded) > + count_vm_events(THP_MIGRATION_SUCCESS, nr_thp_succeeded); > + if (nr_thp_failed) > + count_vm_events(THP_MIGRATION_FAILURE, nr_thp_failed); > + if (nr_thp_split) > + count_vm_events(THP_MIGRATION_SPLIT, nr_thp_split); Are these "if"s worthwhile to have? > + trace_mm_migrate_pages(nr_succeeded, nr_failed, nr_thp_succeeded, > + nr_thp_failed, nr_thp_split, mode, reason);
