linux-kernel - [PATCH v6 01/10] mm: mempolicy: add queue_pages

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Date:   Thu, 25 May 2017 10:19:36 -0400
From:   Zi Yan <zi.yan@...t.com>
To:     n-horiguchi@...jp.nec.com, kirill.shutemov@...ux.intel.com,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org
Cc:     akpm@...ux-foundation.org, minchan@...nel.org, vbabka@...e.cz,
        mgorman@...hsingularity.net, mhocko@...nel.org,
        khandual@...ux.vnet.ibm.com, zi.yan@...rutgers.edu,
        dnellans@...dia.com, dave.hansen@...el.com
Subject: [PATCH v6 01/10] mm: mempolicy: add queue_pages_required()

From: Naoya Horiguchi <n-horiguchi@...jp.nec.com>

Introduce a separate check routine related to MPOL_MF_INVERT flag.
This patch just does cleanup, no behavioral change.

Signed-off-by: Naoya Horiguchi <n-horiguchi@...jp.nec.com>
Signed-off-by: Zi Yan <zi.yan@...rutgers.edu>
---
 mm/mempolicy.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 37d0b334bfe9..64f9eed068b8 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -481,6 +481,21 @@ struct queue_pages {
 };
 
 /*
+ * Check if the page's nid is in qp->nmask.
+ *
+ * If MPOL_MF_INVERT is set in qp->flags, check if the nid is
+ * in the invert of qp->nmask.
+ */
+static inline bool queue_pages_required(struct page *page,
+					struct queue_pages *qp)
+{
+	int nid = page_to_nid(page);
+	unsigned long flags = qp->flags;
+
+	return node_isset(nid, *qp->nmask) == !(flags & MPOL_MF_INVERT);
+}
+
+/*
  * Scan through pages checking if pages follow certain conditions,
  * and move them to the pagelist if they do.
  */
@@ -533,8 +548,7 @@ static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr,
 		 */
 		if (PageReserved(page))
 			continue;
-		nid = page_to_nid(page);
-		if (node_isset(nid, *qp->nmask) == !!(flags & MPOL_MF_INVERT))
+		if (!queue_pages_required(page, qp))
 			continue;
 		if (PageTransCompound(page)) {
 			get_page(page);
@@ -566,7 +580,6 @@ static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask,
 #ifdef CONFIG_HUGETLB_PAGE
 	struct queue_pages *qp = walk->private;
 	unsigned long flags = qp->flags;
-	int nid;
 	struct page *page;
 	spinlock_t *ptl;
 	pte_t entry;
@@ -576,8 +589,7 @@ static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask,
 	if (!pte_present(entry))
 		goto unlock;
 	page = pte_page(entry);
-	nid = page_to_nid(page);
-	if (node_isset(nid, *qp->nmask) == !!(flags & MPOL_MF_INVERT))
+	if (!queue_pages_required(page, qp))
 		goto unlock;
 	/* With MPOL_MF_MOVE, we migrate only unshared hugepage. */
 	if (flags & (MPOL_MF_MOVE_ALL) ||
-- 
2.11.0