From: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Date: Thu, 29 Mar 2012 20:58:17 +0000 (-0700)
Subject: pagemap: remove remaining unneeded spin_lock()
X-Git-Tag: v3.4~258^2~16
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=10bdfb5ef7e1a429a3de31e498942a8ae5749a46;p=platform%2Fkernel%2Flinux-amlogic.git

pagemap: remove remaining unneeded spin_lock()

Commit 025c5b2451e4 ("thp: optimize away unnecessary page table
locking") moves spin_lock() into pmd_trans_huge_lock() in order to avoid
locking unless pmd is for thp.  So this spin_lock() is a bug.

Reported-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index c283832..2b9a760 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -783,7 +783,6 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 
 	/* find the first VMA at or above 'addr' */
 	vma = find_vma(walk->mm, addr);
-	spin_lock(&walk->mm->page_table_lock);
 	if (pmd_trans_huge_lock(pmd, vma) == 1) {
 		for (; addr != end; addr += PAGE_SIZE) {
 			unsigned long offset;