mm/khugepaged: add missed tracepoint for collapse_huge_page_swapin

One return case of `__collapse_huge_page_swapin()` does not invoke
tracepoint while every other return case does.  This commit adds a
tracepoint invocation for the case.

Link: http://lkml.kernel.org/r/20170507101813.30187-1-sj38.park@gmail.com
Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 7cb9c88bb4a3..d1943e54ba95 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -907,8 +907,10 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm,
                                 return false;
                         }
                         /* check if the pmd is still valid */
-                        if (mm_find_pmd(mm, address) != pmd)
+                        if (mm_find_pmd(mm, address) != pmd) {
+                                trace_mm_collapse_huge_page_swapin(mm, swapped_in, referenced, 0);
                                 return false;
+                        }
                 }
                 if (ret & VM_FAULT_ERROR) {
                         trace_mm_collapse_huge_page_swapin(mm, swapped_in, referenced, 0);