tree 696f6164980d678f6ac8c9f796508bf7c9c778fa
parent 0a6b76dd23fa08c5fd7b68acdb55018a37afd4aa
author Kirill A. Shutemov <kirill.shutemov@linux.intel.com> 1458249525 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1458252574 -0700

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>