[PATCH] MIPS/mm: add compound tail page _mapcount when mapped

From 3dc19ea2b535719d0b4177f17bbbff9cbf257b23 Mon Sep 17 00:00:00 2001

From: Jovi Zhang <redacted>
Date: Wed, 22 Aug 2012 10:34:08 +0800
Subject: [PATCH] MIPS/mm: add compound tail page _mapcount when mapped

see commit b6999b191 which target for x86 mm/gup, let it align with
mips architecture.

Quote from commit b6999b191:
    "If compound pages are used and the page is a
    tail page, gup_huge_pmd() increases _mapcount to record tail page are
    mapped while gup_huge_pud does not do that."

Signed-off-by: Jovi Zhang <redacted>
Cc: Youquan Song <redacted>
Cc: Andi Kleen <redacted>
Cc: <redacted>
---
 arch/mips/mm/gup.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/mips/mm/gup.c b/arch/mips/mm/gup.c
index 33aadbc..dcfd573 100644
--- a/arch/mips/mm/gup.c
+++ b/arch/mips/mm/gup.c

@@ -152,6 +152,8 @@ static int gup_huge_pud(pud_t pud, unsigned long

addr, unsigned long end,
 	do {
 		VM_BUG_ON(compound_head(page) != head);
 		pages[*nr] = page;
+		if (PageTail(page))
+			get_huge_page_tail(page);
 		(*nr)++;
 		page++;
 		refs++;
-- 
1.7.9.7