The patch titled
Subject: zram: recalculate zstd compression params once
has been added to the -mm mm-unstable branch. Its filename is
zram-recalculate-zstd-compression-params-once.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/zram-recalculate-zstd-compression-params-once.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Subject: zram: recalculate zstd compression params once
Date: Mon, 2 Sep 2024 19:56:02 +0900
zstd compression params depends on level, but are constant for a given
instance of zstd compression backend. Calculate once (during ctx
creation).
Link: https://lkml.kernel.org/r/20240902105656.1383858-15-senozhatsky@xxxxxxxxxxxx
Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Nick Terrell <terrelln@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/block/zram/backend_zstd.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/drivers/block/zram/backend_zstd.c~zram-recalculate-zstd-compression-params-once
+++ a/drivers/block/zram/backend_zstd.c
@@ -10,6 +10,7 @@
struct zstd_ctx {
zstd_cctx *cctx;
zstd_dctx *dctx;
+ zstd_parameters cprm;
void *cctx_mem;
void *dctx_mem;
s32 level;
@@ -40,6 +41,7 @@ static void *zstd_create(struct zcomp_pa
ctx->level = zstd_default_clevel();
prm = zstd_get_params(ctx->level, PAGE_SIZE);
+ ctx->cprm = zstd_get_params(ctx->level, PAGE_SIZE);
sz = zstd_cctx_workspace_bound(&prm.cParams);
ctx->cctx_mem = vzalloc(sz);
if (!ctx->cctx_mem)
@@ -69,11 +71,10 @@ static int zstd_compress(void *ctx, cons
unsigned char *dst, size_t *dst_len)
{
struct zstd_ctx *zctx = ctx;
- const zstd_parameters prm = zstd_get_params(zctx->level, PAGE_SIZE);
size_t ret;
ret = zstd_compress_cctx(zctx->cctx, dst, *dst_len,
- src, src_len, &prm);
+ src, src_len, &zctx->cprm);
if (zstd_is_error(ret))
return -EINVAL;
*dst_len = ret;
_
Patches currently in -mm which might be from senozhatsky@xxxxxxxxxxxx are
lib-zstd-export-api-needed-for-dictionary-support.patch
lib-lz4hc-export-lz4_resetstreamhc-symbol.patch
lib-zstd-fix-null-deref-in-zstd_createcdict_advanced2.patch
zram-introduce-custom-comp-backends-api.patch
zram-add-lzo-and-lzorle-compression-backends-support.patch
zram-add-lz4-compression-backend-support.patch
zram-add-lz4hc-compression-backend-support.patch
zram-add-zstd-compression-backend-support.patch
zram-pass-estimated-src-size-hint-to-zstd.patch
zram-add-zlib-compression-backend-support.patch
zram-add-842-compression-backend-support.patch
zram-check-that-backends-array-has-at-least-one-backend.patch
zram-introduce-zcomp_params-structure.patch
zram-recalculate-zstd-compression-params-once.patch
zram-introduce-algorithm_params-device-attribute.patch
zram-add-support-for-dict-comp-config.patch
zram-introduce-zcomp_req-structure.patch
zram-introduce-zcomp_ctx-structure.patch
zram-move-immutable-comp-params-away-from-per-cpu-context.patch
zram-add-dictionary-support-to-lz4.patch
zram-add-dictionary-support-to-lz4hc.patch
zram-add-dictionary-support-to-zstd-backend.patch
documentation-zram-add-documentation-for-algorithm-parameters.patch
zram-support-priority-parameter-in-recompression.patch
