[PATCH 20/45] fs/proc: Enable gather_pte_stats to handle cont-pte mapped hugetlb vmas

[Oscar Salvador <osalvador@suse.de>]

HugeTLB pages can be cont-pte mapped, so teach smaps_pte_entry to handle
them.

Signed-off-by: Oscar Salvador <osalvador@suse.de>
---
 fs/proc/task_mmu.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index e13754d3246e..98dd03c26e68 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -3175,6 +3175,7 @@ static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
 	spinlock_t *ptl;
 	pte_t *orig_pte;
 	pte_t *pte;
+	unsigned long size = PAGE_SIZE, cont_ptes = 1;
 
 #ifdef CONFIG_PGTABLE_HAS_HUGE_LEAVES
 	ptl = pmd_huge_lock(pmd, vma);
@@ -3200,6 +3201,10 @@ static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
 		walk->action = ACTION_AGAIN;
 		return 0;
 	}
+	if (pte_cont(ptep_get(pte))) {
+		size = PAGE_SIZE * CONT_PTES;
+		cont_ptes = CONT_PTES;
+	}
 	do {
 		pte_t ptent = ptep_get(pte);
 		struct page *page = can_gather_numa_stats(ptent, vma, addr);
@@ -3207,7 +3212,7 @@ static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
 			continue;
 		gather_stats(page, md, pte_dirty(ptent), 1);
 
-	} while (pte++, addr += PAGE_SIZE, addr != end);
+	} while (pte += cont_ptes, addr += size, addr != end);
 	pte_unmap_unlock(orig_pte, ptl);
 	cond_resched();
 	return 0;
-- 
2.26.2