[PATCH] pagemap: remove remaining unneeded spin_lock()

From: Naoya Horiguchi
Date: Thu Mar 29 2012 - 04:40:25 EST


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@xxxxxxxxx>
Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
fs/proc/task_mmu.c | 1 -
1 files changed, 0 insertions(+), 1 deletions(-)

diff --git linux-3.3.0-6658a6991ce.orig/fs/proc/task_mmu.c linux-3.3.0-6658a6991ce/fs/proc/task_mmu.c
index 9694cc2..06d2b70 100644
--- linux-3.3.0-6658a6991ce.orig/fs/proc/task_mmu.c
+++ linux-3.3.0-6658a6991ce/fs/proc/task_mmu.c
@@ -786,7 +786,6 @@ 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;
--
1.7.7.6

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