On 03/12/2024 14:17, David Hildenbrand wrote: > On 03.12.24 14:49, Wenchao Hao wrote: >> Currently, /proc/xxx/smaps reports the size of anonymous huge pages for >> each VMA, but it does not include large pages smaller than PMD size. >> >> This patch adds the statistics of anonymous huge pages allocated by >> mTHP which is smaller than PMD size to AnonHugePages field in smaps. >> >> Signed-off-by: Wenchao Hao <haowenchao22@xxxxxxxxx> >> --- >> fs/proc/task_mmu.c | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c >> index 38a5a3e9cba2..b655011627d8 100644 >> --- a/fs/proc/task_mmu.c >> +++ b/fs/proc/task_mmu.c >> @@ -717,6 +717,12 @@ static void smaps_account(struct mem_size_stats *mss, >> struct page *page, >> if (!folio_test_swapbacked(folio) && !dirty && >> !folio_test_dirty(folio)) >> mss->lazyfree += size; >> + >> + /* >> + * Count large pages smaller than PMD size to anonymous_thp >> + */ >> + if (!compound && PageHead(page) && folio_order(folio)) >> + mss->anonymous_thp += folio_size(folio); >> } >> if (folio_test_ksm(folio)) > > > I think we decided to leave this (and /proc/meminfo) be one of the last > interfaces where this is only concerned with PMD-sized ones: > > Documentation/admin-guide/mm/transhuge.rst: > > The number of PMD-sized anonymous transparent huge pages currently used by the > system is available by reading the AnonHugePages field in ``/proc/meminfo``. > To identify what applications are using PMD-sized anonymous transparent huge > pages, it is necessary to read ``/proc/PID/smaps`` and count the AnonHugePages > fields for each mapping. (Note that AnonHugePages only applies to traditional > PMD-sized THP for historical reasons and should have been called > AnonHugePmdMapped). > Agreed. If you need per-process metrics for mTHP, we have a python script at tools/mm/thpmaps which does a fairly good job of parsing pagemap. --help gives you all the options.
