linux-kernel - [PATCH v4 05/12] zsmalloc: use bit_spin

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Message-Id: <1461743305-19970-6-git-send-email-minchan@kernel.org>
Date:	Wed, 27 Apr 2016 16:48:18 +0900
From:	Minchan Kim <minchan@...nel.org>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	linux-kernel@...r.kernel.org, linux-mm@...ck.org,
	Minchan Kim <minchan@...nel.org>,
	Sergey Senozhatsky <sergey.senozhatsky@...il.com>
Subject: [PATCH v4 05/12] 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.

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

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 8649d0243e6c..d75d9e4b6a4d 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -864,21 +864,17 @@ 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