linux-kernel - [PATCH] mm: fix account pmd page to the process

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Date:	Thu, 16 Jun 2016 19:13:53 +0800
From:	zhongjiang <zhongjiang@...wei.com>
To:	<kirill.shutemov@...ux.intel.com>, <akpm@...ux-foundation.org>
CC:	<linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>
Subject: [PATCH] mm: fix account pmd page to the process

From: zhong jiang <zhongjiang@...wei.com>

when a process acquire a pmd table shared by other process, we
increase the account to current process. otherwise, a race result
in other tasks have set the pud entry. so it no need to increase it.

Signed-off-by: zhong jiang <zhongjiang@...wei.com>
---
 mm/hugetlb.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 19d0d08..3b025c5 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -4189,10 +4189,9 @@ pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
 	if (pud_none(*pud)) {
 		pud_populate(mm, pud,
 				(pmd_t *)((unsigned long)spte & PAGE_MASK));
-	} else {
+	} else 
 		put_page(virt_to_page(spte));
-		mm_inc_nr_pmds(mm);
-	}
+
 	spin_unlock(ptl);
 out:
 	pte = (pte_t *)pmd_alloc(mm, pud, addr);
-- 
1.8.3.1