[PATCH 3/3] staging, zram: use zs_mem_[read/write]

From: Joonsoo Kim
Date: Wed Jan 16 2013 - 03:09:08 EST


Now, we have newly introduced APIs which reduce copy overhead of
zsmalloc for objects on page boundary.
So use it in zram.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>

diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c
index fb4a7c9..554a742 100644
--- a/drivers/staging/zram/zram_drv.c
+++ b/drivers/staging/zram/zram_drv.c
@@ -195,13 +195,14 @@ static int zram_decompress_page(struct zram *zram, char *mem, u32 index)
return 0;
}

- cmem = zs_map_object(zram->mem_pool, handle, ZS_MM_RO);
if (zram->table[index].size == PAGE_SIZE)
- memcpy(mem, cmem, PAGE_SIZE);
- else
+ zs_mem_read(zram->mem_pool, handle, mem, 0, PAGE_SIZE);
+ else {
+ cmem = zs_map_object(zram->mem_pool, handle, ZS_MM_RO);
ret = lzo1x_decompress_safe(cmem, zram->table[index].size,
mem, &clen);
- zs_unmap_object(zram->mem_pool, handle);
+ zs_unmap_object(zram->mem_pool, handle);
+ }

/* Should NEVER happen. Return bio error if it does. */
if (unlikely(ret != LZO_E_OK)) {
@@ -269,7 +270,7 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
size_t clen;
unsigned long handle;
struct page *page;
- unsigned char *user_mem, *cmem, *src, *uncmem = NULL;
+ unsigned char *user_mem, *src, *uncmem = NULL;

page = bvec->bv_page;
src = zram->compress_buffer;
@@ -343,11 +344,8 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, u32 index,
ret = -ENOMEM;
goto out;
}
- cmem = zs_map_object(zram->mem_pool, handle, ZS_MM_WO);
-
- memcpy(cmem, src, clen);

- zs_unmap_object(zram->mem_pool, handle);
+ zs_mem_write(zram->mem_pool, handle, src, 0, clen);

zram->table[index].handle = handle;
zram->table[index].size = clen;
--
1.7.9.5

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