[PATCH] kbuild: use smaller dictionary size for zstd module compression

From: Piotr Gorski
Date: Fri Sep 10 2021 - 09:10:10 EST


By default, zstd without parameters uses a dictionary size of 8 MB.
However, most modules are much smaller than that.
Use a dictionary size of 2 MB for module compression, resulting in
slightly higher compression speed while still maintaining a good
compression ratio.
The --zstd=wlog=21 option is equivalent to --lzma2=dict=2MiB used in XZ compression.

Signed-off-by: Piotr Gorski <lucjan.lucjanov@xxxxxxxxx>
---
scripts/Makefile.modinst | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/Makefile.modinst b/scripts/Makefile.modinst
index ff9b09e4cfca..c3475e5aca7c 100644
--- a/scripts/Makefile.modinst
+++ b/scripts/Makefile.modinst
@@ -97,7 +97,7 @@ quiet_cmd_gzip = GZIP $@
quiet_cmd_xz = XZ $@
cmd_xz = $(XZ) --lzma2=dict=2MiB -f $<
quiet_cmd_zstd = ZSTD $@
- cmd_zstd = $(ZSTD) -T0 --rm -f -q $<
+ cmd_zstd = $(ZSTD) --zstd=wlog=21 -T0 --rm -f -q $<

$(dst)/%.ko.gz: $(dst)/%.ko FORCE
$(call cmd,gzip)
--
2.33.0.142.ge0a2f5cbc5