linux-kernel - [PATCH 5/7] Remove redundant check for zero page

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Date:	Thu, 28 Jan 2010 21:13:41 +0530
From:	Nitin Gupta <ngupta@...are.org>
To:	Greg KH <greg@...ah.com>
Cc:	Pekka Enberg <penberg@...helsinki.fi>,
	linux-kernel <linux-kernel@...r.kernel.org>
Subject: [PATCH 5/7] Remove redundant check for zero page

ramzswap_free_page() already handles the case for zero filled
pages. So, remove redundant logic for the same in ramzswap_write().

Signed-off-by: Nitin Gupta <ngupta@...are.org>
---
 drivers/staging/ramzswap/ramzswap_drv.c |   15 +++++----------
 1 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/ramzswap/ramzswap_drv.c b/drivers/staging/ramzswap/ramzswap_drv.c
index 3035add..7e0a3fa 100644
--- a/drivers/staging/ramzswap/ramzswap_drv.c
+++ b/drivers/staging/ramzswap/ramzswap_drv.c
@@ -593,6 +593,10 @@ static void ramzswap_free_page(struct ramzswap *rzs, size_t index)
 	u32 offset = rzs->table[index].offset;
 
 	if (unlikely(!page)) {
+		/*
+		 * No memory is allocated for zero filled pages.
+		 * Simply clear zero page flag.
+		 */
 		if (rzs_test_flag(rzs, index, RZS_ZERO)) {
 			rzs_clear_flag(rzs, index, RZS_ZERO);
 			rzs_stat_dec(&rzs->stats.pages_zero);
@@ -789,18 +793,9 @@ static int ramzswap_write(struct ramzswap *rzs, struct bio *bio)
 	 * is no longer referenced by any process. So, its now safe
 	 * to free the memory that was allocated for this page.
 	 */
-	if (rzs->table[index].page)
+	if (rzs->table[index].page || rzs_test_flag(rzs, index, RZS_ZERO))
 		ramzswap_free_page(rzs, index);
 
-	/*
-	 * No memory is allocated for zero filled pages.
-	 * Simply clear zero page flag.
-	 */
-	if (rzs_test_flag(rzs, index, RZS_ZERO)) {
-		rzs_stat_dec(&rzs->stats.pages_zero);
-		rzs_clear_flag(rzs, index, RZS_ZERO);
-	}
-
 	mutex_lock(&rzs->lock);
 
 	user_mem = kmap_atomic(page, KM_USER0);
-- 
1.6.2.5

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