On 20/12/2024 17:41, Christoph Lameter (Ampere) wrote: > On Tue, 17 Dec 2024, Ryan Roberts wrote: > >> We previously decided that all existing THP stats would continue to only count >> PMD-sized THP for fear of breaking userspace in subtle ways, and instead would >> introduce new mTHP stats that can count for each order. We already have >> MTHP_STAT_ANON_FAULT_ALLOC and MTHP_STAT_ANON_FAULT_FALLBACK (amongst others) so >> these new stats fit the pattern well, IMHO. > > Could we move all the stats somewhere into sysfs where we can get them by > page order? /proc/vmstat keeps getting new counters. This is exactly what has been done already for mthp stats. They live at: /sys/kernel/mm/transparent_hugepage/hugepages-<size>kB/stats/. So there is a directory per size, and there is a file per stat.
