[PATCH 4/7] highmem: remove pool_lock

[Lai Jiangshan]

The accesses to the pool are always in kmap_lock critical region,
thus pool_lock is not needed.

Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxx>
---
 mm/highmem.c |    6 ------
 1 files changed, 0 insertions(+), 6 deletions(-)

diff --git a/mm/highmem.c b/mm/highmem.c
index b6ce085..bf7f168 100644
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -316,7 +316,6 @@ struct page_address_map {
  * page_address_map freelist, allocated from page_address_maps.
  */
 static struct list_head page_address_pool;	/* freelist */
-static spinlock_t pool_lock;			/* protects page_address_pool */
 
 /*
  * Hash table bucket
@@ -383,11 +382,9 @@ static void set_high_page_address(struct page *page, void *virtual)
 	if (virtual) {		/* Add */
 		BUG_ON(list_empty(&page_address_pool));
 
-		spin_lock_irqsave(&pool_lock, flags);
 		pam = list_entry(page_address_pool.next,
 				struct page_address_map, list);
 		list_del(&pam->list);
-		spin_unlock_irqrestore(&pool_lock, flags);
 
 		pam->page = page;
 		pam->virtual = virtual;
@@ -401,9 +398,7 @@ static void set_high_page_address(struct page *page, void *virtual)
 			if (pam->page == page) {
 				list_del(&pam->list);
 				spin_unlock_irqrestore(&pas->lock, flags);
-				spin_lock_irqsave(&pool_lock, flags);
 				list_add_tail(&pam->list, &page_address_pool);
-				spin_unlock_irqrestore(&pool_lock, flags);
 				goto done;
 			}
 		}
@@ -426,7 +421,6 @@ void __init page_address_init(void)
 		INIT_LIST_HEAD(&page_address_htable[i].lh);
 		spin_lock_init(&page_address_htable[i].lock);
 	}
-	spin_lock_init(&pool_lock);
 }
 
 #endif	/* defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL) */
-- 
1.7.7

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