mm, highmem: remove useless pool_lock
The pool_lock protects the page_address_pool from concurrent access. But,
access to the page_address_pool is already protected by kmap_lock. So
remove it.
Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kin <minchan@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/highmem.c b/mm/highmem.c
index 2576a71..f0f0f1d 100644
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -328,7 +328,6 @@
* 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
@@ -395,11 +394,9 @@
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;
@@ -413,9 +410,7 @@
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;
}
}
@@ -438,7 +433,6 @@
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) */