[PATCH v5 05/12] zsmalloc: use bit_spin_lock

Minchan Kim
2016-05-09T02:21:52Z

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.

Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
---
mm/zsmalloc.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 3c2574be8cee..718dde7fd028 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -867,21 +867,17 @@ 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)
--
1.9.1