[PATCH 3/4] zstd: move params structure to global variable to reduce stack usage

From: Maninder Singh
Date: Mon Jun 03 2019 - 05:11:12 EST


As params structure remains same for lifetime, just initialise it
at init time and make it global variable.

Signed-off-by: Maninder Singh <maninder1.s@xxxxxxxxxxx>
Signed-off-by: Vaneet Narang <v.narang@xxxxxxxxxxx>
---
crypto/zstd.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/crypto/zstd.c b/crypto/zstd.c
index 4e9ff22..80a9e5c 100644
--- a/crypto/zstd.c
+++ b/crypto/zstd.c
@@ -32,6 +32,8 @@ struct zstd_ctx {
void *dwksp;
};

+static ZSTD_parameters params;
+
static ZSTD_parameters zstd_params(void)
{
return ZSTD_getParams(ZSTD_DEF_LEVEL, 0, 0);
@@ -40,8 +42,10 @@ static ZSTD_parameters zstd_params(void)
static int zstd_comp_init(struct zstd_ctx *ctx)
{
int ret = 0;
- const ZSTD_parameters params = zstd_params();
- const size_t wksp_size = ZSTD_CCtxWorkspaceBound(params.cParams);
+ size_t wksp_size;
+
+ params = zstd_params();
+ wksp_size = ZSTD_CCtxWorkspaceBound(params.cParams);

ctx->cwksp = vzalloc(wksp_size);
if (!ctx->cwksp) {
@@ -160,7 +164,6 @@ static int __zstd_compress(const u8 *src, unsigned int slen,
{
size_t out_len;
struct zstd_ctx *zctx = ctx;
- const ZSTD_parameters params = zstd_params();

out_len = ZSTD_compressCCtx(zctx->cctx, dst, *dlen, src, slen, &params);
if (ZSTD_isError(out_len))
--
2.7.4