[PATCH 2/5] mm/zswap: change dstmem size to one page

[Chengming Zhou]

Change the dstmem size from 2 * PAGE_SIZE to only one page since
we only need at most one page when compress, and the "dlen" is also
PAGE_SIZE in acomp_request_set_params(). If the output size > PAGE_SIZE
we don't wanna store the output in zswap anyway.

So change it to one page, and delete the stale comment.

Signed-off-by: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>
---
 mm/zswap.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/mm/zswap.c b/mm/zswap.c
index edb8b45ed5a1..fa186945010d 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -707,7 +707,7 @@ static int zswap_dstmem_prepare(unsigned int cpu)
 	struct mutex *mutex;
 	u8 *dst;
 
-	dst = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, cpu_to_node(cpu));
+	dst = kmalloc_node(PAGE_SIZE, GFP_KERNEL, cpu_to_node(cpu));
 	if (!dst)
 		return -ENOMEM;
 
@@ -1662,8 +1662,7 @@ bool zswap_store(struct folio *folio)
 	sg_init_table(&input, 1);
 	sg_set_page(&input, page, PAGE_SIZE, 0);
 
-	/* zswap_dstmem is of size (PAGE_SIZE * 2). Reflect same in sg_list */
-	sg_init_one(&output, dst, PAGE_SIZE * 2);
+	sg_init_one(&output, dst, PAGE_SIZE);
 	acomp_request_set_params(acomp_ctx->req, &input, &output, PAGE_SIZE, dlen);
 	/*
 	 * it maybe looks a little bit silly that we send an asynchronous request,

-- 
b4 0.10.1