[RFC PATCH 3/6] perf: change the condition of identifying hugetlb vm

Wenwei Tao
2015-06-10T06:45:56Z

Hugetlb VMAs are not mergeable, that means a VMA couldn't have VM_HUGETLB and
VM_MERGEABLE been set in the same time. So we use VM_HUGETLB to indicate new
mergeable VMAs. Because of that a VMA which has VM_HUGETLB been set is a hugetlb
VMA only if it doesn't have VM_MERGEABLE been set in the same time.

Signed-off-by: Wenwei Tao <wenweitaowenwei@gmail.com>
---
kernel/events/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index f04daab..6313bdd 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5624,7 +5624,7 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
flags |= MAP_EXECUTABLE;
if (vma->vm_flags & VM_LOCKED)
flags |= MAP_LOCKED;
- if (vma->vm_flags & VM_HUGETLB)
+ if ((vma->vm_flags & (VM_HUGETLB | VM_MERGEABLE)) == VM_HUGETLB)
flags |= MAP_HUGETLB;

goto got_name;
--
1.7.9.5