diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2016-03-17 14:18:45 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-17 15:09:34 -0700 |
| commit | f9719a03de51e13526d614e79d002f838770b2d6 (patch) | |
| tree | 696f6164980d678f6ac8c9f796508bf7c9c778fa /mm | |
| parent | 0a6b76dd23fa08c5fd7b68acdb55018a37afd4aa (diff) | |
thp, vmstats: count deferred split events
Count how many times we put a THP in split queue. Currently, it happens
on partial unmap of a THP.
Rapidly growing value can indicate that an application behaves
unfriendly wrt THP: often fault in huge page and then unmap part of it.
This leads to unnecessary memory fragmentation and the application may
require tuning.
The event also can help with debugging kernel [mis-]behaviour.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/huge_memory.c | 1 | ||||
| -rw-r--r-- | mm/vmstat.c | 1 |
2 files changed, 2 insertions, 0 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 1ea21e203a70..1dddfb21fc22 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3455,6 +3455,7 @@ void deferred_split_huge_page(struct page *page) spin_lock_irqsave(&pgdata->split_queue_lock, flags); if (list_empty(page_deferred_list(page))) { + count_vm_event(THP_DEFERRED_SPLIT_PAGE); list_add_tail(page_deferred_list(page), &pgdata->split_queue); pgdata->split_queue_len++; } diff --git a/mm/vmstat.c b/mm/vmstat.c index f80066248c94..5e4300482897 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -848,6 +848,7 @@ const char * const vmstat_text[] = { "thp_collapse_alloc_failed", "thp_split_page", "thp_split_page_failed", + "thp_deferred_split_page", "thp_split_pmd", "thp_zero_page_alloc", "thp_zero_page_alloc_failed", |