linux-kernel - [PATCH 2/2] zram/zcomp: do not zero out zcomp private pages

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Message-Id: <1448598194-24754-3-git-send-email-sergey.senozhatsky@gmail.com>
Date:	Fri, 27 Nov 2015 13:23:14 +0900
From:	Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Minchan Kim <minchan@...nel.org>, linux-kernel@...r.kernel.org,
	Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>,
	Sergey Senozhatsky <sergey.senozhatsky@...il.com>
Subject: [PATCH 2/2] zram/zcomp: do not zero out zcomp private pages

Do not __GFP_ZERO allocated zcomp ->private pages. We keep
allocated streams around and use them for read/write requests,
so we supply a zeroed out ->private to compression algorithm
as a scratch buffer only once -- the first time we use that
stream. For the rest of IO requests served by this stream
->private usually contains some temporarily data from the
previous requests.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@...il.com>
---
 drivers/block/zram/zcomp_lz4.c | 4 ++--
 drivers/block/zram/zcomp_lzo.c | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/block/zram/zcomp_lz4.c b/drivers/block/zram/zcomp_lz4.c
index dc2338d..0110086 100644
--- a/drivers/block/zram/zcomp_lz4.c
+++ b/drivers/block/zram/zcomp_lz4.c
@@ -19,10 +19,10 @@ static void *zcomp_lz4_create(gfp_t flags)
 {
 	void *ret;
 
-	ret = kzalloc(LZ4_MEM_COMPRESS, flags);
+	ret = kmalloc(LZ4_MEM_COMPRESS, flags);
 	if (!ret)
 		ret = __vmalloc(LZ4_MEM_COMPRESS,
-				flags | __GFP_ZERO | __GFP_HIGHMEM,
+				flags | __GFP_HIGHMEM,
 				PAGE_KERNEL);
 	return ret;
 }
diff --git a/drivers/block/zram/zcomp_lzo.c b/drivers/block/zram/zcomp_lzo.c
index 0ab6fce..ed7a1f0 100644
--- a/drivers/block/zram/zcomp_lzo.c
+++ b/drivers/block/zram/zcomp_lzo.c
@@ -19,10 +19,10 @@ static void *lzo_create(gfp_t flags)
 {
 	void *ret;
 
-	ret = kzalloc(LZO1X_MEM_COMPRESS, flags);
+	ret = kmalloc(LZO1X_MEM_COMPRESS, flags);
 	if (!ret)
 		ret = __vmalloc(LZO1X_MEM_COMPRESS,
-				flags | __GFP_ZERO | __GFP_HIGHMEM,
+				flags | __GFP_HIGHMEM,
 				PAGE_KERNEL);
 	return ret;
 }
-- 
2.6.3.368.gf34be46

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