[PATCH 0/2] ZRAM Cleanup

[PATCH 0/2] ZRAM Cleanup

[Marcos Paulo de Souza]

These two patches cleans a little the zram driver.

I hope you enjoy :)

Marcos Paulo de Souza (2):
  staging: zram: Remove dead code
  staging: zram: Remove useless struct zobj_header

 drivers/staging/zram/zram_drv.c |   18 +++---------------
 drivers/staging/zram/zram_drv.h |   12 ------------
 2 files changed, 3 insertions(+), 27 deletions(-)

-- 
1.7.10.2

[PATCH 1/2] staging: zram: Remove some dead code

[Marcos Paulo de Souza]

This patch removes code that is never executed by zram.

Signed-off-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com>
---
 drivers/staging/zram/zram_drv.c |    9 ---------
 drivers/staging/zram/zram_drv.h |    3 ---
 2 files changed, 12 deletions(-)

diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c
index 685d612..5216ee1 100644
--- a/drivers/staging/zram/zram_drv.c
+++ b/drivers/staging/zram/zram_drv.c
@@ -415,15 +415,6 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
 	cmem = zs_map_object(zram->mem_pool, handle);
 
 memstore:
-#if 0
-	/* Back-reference needed for memory defragmentation */
-	if (!zram_test_flag(zram, index, ZRAM_UNCOMPRESSED)) {
-		zheader = (struct zobj_header *)cmem;
-		zheader->table_idx = index;
-		cmem += sizeof(*zheader);
-	}
-#endif
-
 	memcpy(cmem, src, clen);
 
 	if (unlikely(zram_test_flag(zram, index, ZRAM_UNCOMPRESSED))) {
diff --git a/drivers/staging/zram/zram_drv.h b/drivers/staging/zram/zram_drv.h
index fbe8ac9..fe3f8fe 100644
--- a/drivers/staging/zram/zram_drv.h
+++ b/drivers/staging/zram/zram_drv.h
@@ -33,9 +33,6 @@ static const unsigned max_num_devices = 32;
  * object. This is required to support memory defragmentation.
  */
 struct zobj_header {
-#if 0
-	u32 table_idx;
-#endif
 };
 
 /*-- Configurable parameters */
-- 
1.7.10.2

[PATCH 2/2] staging: zram: Remove useless struct zobj_header

[Marcos Paulo de Souza]

The struct zobj_header has no members, so the sizeof(struct zobj_header *)
always returns zero. For this reason we are removing this useless struct.

Signed-off-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com>
---
 drivers/staging/zram/zram_drv.c |    9 +++------
 drivers/staging/zram/zram_drv.h |    9 ---------
 2 files changed, 3 insertions(+), 15 deletions(-)

diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c
index 5216ee1..a79a20d 100644
--- a/drivers/staging/zram/zram_drv.c
+++ b/drivers/staging/zram/zram_drv.c
@@ -209,7 +209,6 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
 	int ret;
 	size_t clen;
 	struct page *page;
-	struct zobj_header *zheader;
 	unsigned char *user_mem, *cmem, *uncmem = NULL;
 
 	page = bvec->bv_page;
@@ -249,7 +248,7 @@ static int zram_bvec_read(struct zram *zram, struct bio_vec *bvec,
 
 	cmem = zs_map_object(zram->mem_pool, zram->table[index].handle);
 
-	ret = lzo1x_decompress_safe(cmem + sizeof(*zheader),
+	ret = lzo1x_decompress_safe(cmem,
 				    zram->table[index].size,
 				    uncmem, &clen);
 
@@ -278,7 +277,6 @@ static int zram_read_before_write(struct zram *zram, char *mem, u32 index)
 {
 	int ret;
 	size_t clen = PAGE_SIZE;
-	struct zobj_header *zheader;
 	unsigned char *cmem;
 
 	if (zram_test_flag(zram, index, ZRAM_ZERO) ||
@@ -296,7 +294,7 @@ static int zram_read_before_write(struct zram *zram, char *mem, u32 index)
 		return 0;
 	}
 
-	ret = lzo1x_decompress_safe(cmem + sizeof(*zheader),
+	ret = lzo1x_decompress_safe(cmem,
 				    zram->table[index].size,
 				    mem, &clen);
 	zs_unmap_object(zram->mem_pool, zram->table[index].handle);
@@ -318,7 +316,6 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
 	u32 store_offset;
 	size_t clen;
 	void *handle;
-	struct zobj_header *zheader;
 	struct page *page, *page_store;
 	unsigned char *user_mem, *cmem, *src, *uncmem = NULL;
 
@@ -405,7 +402,7 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
 		goto memstore;
 	}
 
-	handle = zs_malloc(zram->mem_pool, clen + sizeof(*zheader));
+	handle = zs_malloc(zram->mem_pool, clen);
 	if (!handle) {
 		pr_info("Error allocating memory for compressed "
 			"page: %u, size=%zu\n", index, clen);
diff --git a/drivers/staging/zram/zram_drv.h b/drivers/staging/zram/zram_drv.h
index fe3f8fe..883f313 100644
--- a/drivers/staging/zram/zram_drv.h
+++ b/drivers/staging/zram/zram_drv.h
@@ -26,15 +26,6 @@
  */
 static const unsigned max_num_devices = 32;
 
-/*
- * Stored at beginning of each compressed object.
- *
- * It stores back-reference to table entry which points to this
- * object. This is required to support memory defragmentation.
- */
-struct zobj_header {
-};
-
 /*-- Configurable parameters */
 
 /* Default zram disk size: 25% of total RAM */
-- 
1.7.10.2

Re: [PATCH 0/2] ZRAM Cleanup

[Minchan Kim]

Hi,

On 06/21/2012 12:32 PM, Marcos Paulo de Souza wrote:

> These two patches cleans a little the zram driver.
> 
> I hope you enjoy :)
> 
> Marcos Paulo de Souza (2):
>   staging: zram: Remove dead code
>   staging: zram: Remove useless struct zobj_header
> 
>  drivers/staging/zram/zram_drv.c |   18 +++---------------
>  drivers/staging/zram/zram_drv.h |   12 ------------
>  2 files changed, 3 insertions(+), 27 deletions(-)
> 

It was handled by [1] and on staging already.
[1] https://lkml.org/lkml/2012/6/8/116

Thanks.

-- 
Kind regards,
Minchan Kim

Re: [PATCH 2/2] staging: zram: Remove useless struct zobj_header

[Dan Carpenter]

On Thu, Jun 21, 2012 at 12:32:45AM -0300, Marcos Paulo de Souza wrote:
> The struct zobj_header has no members, so the sizeof(struct zobj_header *)
> always returns zero. For this reason we are removing this useless struct.
> 

I've been out for the past few days and I'm slowly catching up.  If
you want you could update this comment as well:

drivers/staging/zram/zram_drv.h
    40  /*
    41   * NOTE: max_zpage_size must be less than or equal to:
    42   *   ZS_MAX_ALLOC_SIZE - sizeof(struct zobj_header)
    43   * otherwise, xv_malloc() would always return failure.
    44   */

regards,
dan carpenter