From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
vma_has_reserves() can be substituted by using return value of
vma_needs_reservation(). If chg returned by vma_needs_reservation()
is 0, it means that vma has reserves. Otherwise, it means that vma don't
have reserves and need a hugepage outside of reserve pool. This definition
is perfectly same as vma_has_reserves(), so remove vma_has_reserves().
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Signed-off-by: Davidlohr Bueso <davidlohr@xxxxxx>
---
mm/hugetlb.c | 46 +++++++++-------------------------------------
1 file changed, 9 insertions(+), 37 deletions(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 541cceb..83bc161 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -469,39 +469,6 @@ void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
vma->vm_private_data = (void *)0;
}
-/* Returns true if the VMA has associated reserve pages */
-static int vma_has_reserves(struct vm_area_struct *vma, long chg)
-{
- if (vma->vm_flags & VM_NORESERVE) {
- /*
- * This address is already reserved by other process(chg == 0),
- * so, we should decrement reserved count. Without decrementing,
- * reserve count remains after releasing inode, because this
- * allocated page will go into page cache and is regarded as
- * coming from reserved pool in releasing step. Currently, we
- * don't have any other solution to deal with this situation
- * properly, so add work-around here.
- */
- if (vma->vm_flags & VM_MAYSHARE && chg == 0)
- return 1;
- else
- return 0;
- }
-
- /* Shared mappings always use reserves */
- if (vma->vm_flags & VM_MAYSHARE)
- return 1;
-
- /*
- * Only the process that called mmap() has reserves for
- * private mappings.
- */
- if (is_vma_resv_set(vma, HPAGE_RESV_OWNER))
- return 1;
-
- return 0;
-}
-
static void enqueue_huge_page(struct hstate *h, struct page *page)
{
int nid = page_to_nid(page);
@@ -555,10 +522,11 @@ static struct page *dequeue_huge_page_vma(struct hstate *h,
/*
* A child process with MAP_PRIVATE mappings created by their parent
* have no page reserves. This check ensures that reservations are
- * not "stolen". The child may still get SIGKILLed
+ * not "stolen". The child may still get SIGKILLed.
+ * chg represents whether current user has a reserved hugepages or not,
+ * so that we can use it to ensure that reservations are not "stolen".
*/
- if (!vma_has_reserves(vma, chg) &&
- h->free_huge_pages - h->resv_huge_pages == 0)
+ if (chg && h->free_huge_pages - h->resv_huge_pages == 0)
goto err;
/* If reserves cannot be used, ensure enough pages are in the pool */
@@ -577,7 +545,11 @@ retry_cpuset:
if (page) {
if (avoid_reserve)
break;
- if (!vma_has_reserves(vma, chg))
+ /*
+ * chg means whether current user allocates
+ * a hugepage on the reserved pool or not
+ */
+ if (chg)
break;
SetPagePrivate(page);
--
1.8.1.4
--
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