zsmalloc: use bit_spin_lock

Use kernel standard bit spin-lock instead of custom mess.  Even, it has
a bug which doesn't disable preemption.  The reason we don't have any
problem is that we have used it during preemption disable section by
class->lock spinlock.  So no need to go to stable.

Link: http://lkml.kernel.org/r/1464736881-24886-6-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 79295c7..39f29ae 100644 (file)
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -868,21 +868,17 @@ static unsigned long obj_idx_to_offset(struct page *page,
 
 static inline int trypin_tag(unsigned long handle)
 {
-       unsigned long *ptr = (unsigned long *)handle;
-
-       return !test_and_set_bit_lock(HANDLE_PIN_BIT, ptr);
+       return bit_spin_trylock(HANDLE_PIN_BIT, (unsigned long *)handle);
 }
 
 static void pin_tag(unsigned long handle)
 {
-       while (!trypin_tag(handle));
+       bit_spin_lock(HANDLE_PIN_BIT, (unsigned long *)handle);
 }
 
 static void unpin_tag(unsigned long handle)
 {
-       unsigned long *ptr = (unsigned long *)handle;
-
-       clear_bit_unlock(HANDLE_PIN_BIT, ptr);
+       bit_spin_unlock(HANDLE_PIN_BIT, (unsigned long *)handle);
 }
 
 static void reset_page(struct page *page)