linux-kernel - [BUG Fix Patch 2/6] Bug fix: Do not calculate direct mapping pages when freeing vmemmap pagetables.

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Date:	Tue, 15 Jan 2013 18:54:23 +0800
From:	Tang Chen <tangchen@...fujitsu.com>
To:	akpm@...ux-foundation.org, rientjes@...gle.com,
	len.brown@...el.com, benh@...nel.crashing.org, paulus@...ba.org,
	cl@...ux.com, minchan.kim@...il.com,
	kosaki.motohiro@...fujitsu.com, isimatu.yasuaki@...fujitsu.com,
	wujianguo@...wei.com, wency@...fujitsu.com,
	tangchen@...fujitsu.com, hpa@...or.com, linfeng@...fujitsu.com,
	laijs@...fujitsu.com, mgorman@...e.de, yinghai@...nel.org,
	glommer@...allels.com, jiang.liu@...wei.com
Cc:	x86@...nel.org, linux-mm@...ck.org, linux-kernel@...r.kernel.org,
	linuxppc-dev@...ts.ozlabs.org, linux-acpi@...r.kernel.org,
	linux-s390@...r.kernel.org, linux-sh@...r.kernel.org,
	linux-ia64@...r.kernel.org, cmetcalf@...era.com,
	sparclinux@...r.kernel.org
Subject: [BUG Fix Patch 2/6] Bug fix: Do not calculate direct mapping pages when freeing vmemmap pagetables.

We only need to update direct_pages_count[level] when we freeing direct mapped
pagetables.

Signed-off-by: Tang Chen <tangchen@...fujitsu.com>
---
 arch/x86/mm/init_64.c |   17 +++++++----------
 1 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index e829113..368cc3f 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -804,14 +804,13 @@ remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
 
 		if (IS_ALIGNED(addr, PAGE_SIZE) &&
 		    IS_ALIGNED(next, PAGE_SIZE)) {
-			if (!direct) {
+			if (!direct)
 				free_pagetable(pte_page(*pte), 0);
-				pages++;
-			}
 
 			spin_lock(&init_mm.page_table_lock);
 			pte_clear(&init_mm, addr, pte);
 			spin_unlock(&init_mm.page_table_lock);
+			pages++;
 		} else {
 			/*
 			 * If we are not removing the whole page, it means
@@ -824,11 +823,11 @@ remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
 
 			if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
 				free_pagetable(pte_page(*pte), 0);
-				pages++;
 
 				spin_lock(&init_mm.page_table_lock);
 				pte_clear(&init_mm, addr, pte);
 				spin_unlock(&init_mm.page_table_lock);
+				pages++;
 			}
 		}
 	}
@@ -857,15 +856,14 @@ remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end,
 		if (pmd_large(*pmd)) {
 			if (IS_ALIGNED(addr, PMD_SIZE) &&
 			    IS_ALIGNED(next, PMD_SIZE)) {
-				if (!direct) {
+				if (!direct)
 					free_pagetable(pmd_page(*pmd),
 						       get_order(PMD_SIZE));
-					pages++;
-				}
 
 				spin_lock(&init_mm.page_table_lock);
 				pmd_clear(pmd);
 				spin_unlock(&init_mm.page_table_lock);
+				pages++;
 				continue;
 			}
 
@@ -914,15 +912,14 @@ remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
 		if (pud_large(*pud)) {
 			if (IS_ALIGNED(addr, PUD_SIZE) &&
 			    IS_ALIGNED(next, PUD_SIZE)) {
-				if (!direct) {
+				if (!direct)
 					free_pagetable(pud_page(*pud),
 						       get_order(PUD_SIZE));
-					pages++;
-				}
 
 				spin_lock(&init_mm.page_table_lock);
 				pud_clear(pud);
 				spin_unlock(&init_mm.page_table_lock);
+				pages++;
 				continue;
 			}
 
-- 
1.7.1

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