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 <[email protected]>
Signed-off-by: Naoya Horiguchi <[email protected]>
Cc: [email protected]
---
 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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