On Mon, 3 Jun 2019 14:32:03 +0530 Maninder Singh <[email protected]> wrote:
> currently params structure is passed in all functions, which increases > stack usage in all the function and lead to stack overflow on target like > ARM with kernel stack size of 8 KB so better to pass pointer. > > Checked for ARM: > > Original Patched > Call FLow Size: 1264 1040 > .... > (HUF_sort) -> 296 > (HUF_buildCTable_wksp) -> 144 > (HUF_compress4X_repeat) -> 88 > (ZSTD_compressBlock_internal) -> 200 > (ZSTD_compressContinue_internal)-> 136 -> 88 > (ZSTD_compressCCtx) -> 192 -> 64 > (zstd_compress) -> 144 -> 96 > (crypto_compress) -> 32 > (zcomp_compress) -> 32 > .... > > Signed-off-by: Maninder Singh <[email protected]> > Signed-off-by: Vaneet Narang <[email protected]> > You missed btrfs. This needs review, please - particularly the kernel-wide static ZSTD_parameters in zstd_get_btrfs_parameters(). The base patch is here: http://lkml.kernel.org/r/[email protected] --- a/fs/btrfs/zstd.c~zstd-pass-pointer-rathen-than-structure-to-functions-fix +++ a/fs/btrfs/zstd.c @@ -27,15 +27,17 @@ /* 307s to avoid pathologically clashing with transaction commit */ #define ZSTD_BTRFS_RECLAIM_JIFFIES (307 * HZ) -static ZSTD_parameters zstd_get_btrfs_parameters(unsigned int level, +static ZSTD_parameters *zstd_get_btrfs_parameters(unsigned int level, size_t src_len) { - ZSTD_parameters params = ZSTD_getParams(level, src_len, 0); + static ZSTD_parameters params; + + params = ZSTD_getParams(level, src_len, 0); if (params.cParams.windowLog > ZSTD_BTRFS_MAX_WINDOWLOG) params.cParams.windowLog = ZSTD_BTRFS_MAX_WINDOWLOG; WARN_ON(src_len > ZSTD_BTRFS_MAX_INPUT); - return params; + return ¶ms; } struct workspace { @@ -155,11 +157,12 @@ static void zstd_calc_ws_mem_sizes(void) unsigned int level; for (level = 1; level <= ZSTD_BTRFS_MAX_LEVEL; level++) { - ZSTD_parameters params = - zstd_get_btrfs_parameters(level, ZSTD_BTRFS_MAX_INPUT); - size_t level_size = - max_t(size_t, - ZSTD_CStreamWorkspaceBound(params.cParams), + ZSTD_parameters *params; + size_t level_size; + + params = zstd_get_btrfs_parameters(level, ZSTD_BTRFS_MAX_INPUT); + level_size = max_t(size_t, + ZSTD_CStreamWorkspaceBound(params->cParams), ZSTD_DStreamWorkspaceBound(ZSTD_BTRFS_MAX_INPUT)); max_size = max_t(size_t, max_size, level_size); @@ -385,8 +388,9 @@ static int zstd_compress_pages(struct li unsigned long len = *total_out; const unsigned long nr_dest_pages = *out_pages; unsigned long max_out = nr_dest_pages * PAGE_SIZE; - ZSTD_parameters params = zstd_get_btrfs_parameters(workspace->req_level, - len); + ZSTD_parameters *params; + + params = zstd_get_btrfs_parameters(workspace->req_level, len); *out_pages = 0; *total_out = 0; _
