dileks@iniza:~/src/linux/git$ git grep zstd scripts/ | egrep '\-(19|22|T0)' scripts/Makefile.lib: cmd_zstd = cat $(real-prereqs) | $(ZSTD) -19 > $@ scripts/Makefile.lib: cmd_zstd22 = cat $(real-prereqs) | $(ZSTD) -22 --ultra > $@ scripts/Makefile.lib: cmd_zstd22_with_size = { cat $(real-prereqs) | $(ZSTD) -22 --ultra; $(size_append); } > $@ scripts/Makefile.modinst: cmd_zstd = $(ZSTD) -T0 --rm -f -q $< -sed@- On Thu, Jul 25, 2024 at 9:09 PM Sedat Dilek <sedat.dilek@xxxxxxxxx> wrote: > > Hi, > > I am a big fan of ZSTD - here version 1.5.6 on Debian/unstable AMD64. > > When playing with CONFIG_MODULE_COMPRESS_ZSTD=y I observed a 35MiB > greater linux-image Debian file. > > Debian: ~100MiB <--- CONFIG_MODULE_COMPRESS_XZ=y > Selfmade: ~135MiB <--- CONFIG_MODULE_COMPRESS_ZSTD=y > > So, I checked the used compression-level of ZSTD in the build-process: > > [ vmlinux.bin.zst ] > $ grep zstd build-log_6.10.1-1-amd64-clang18-kcfi.txt | grep vmlinux.bin.zst > { cat arch/x86/boot/compressed/vmlinux.bin > arch/x86/boot/compressed/vmlinux.relocs | zstd -22 --ultra; printf > \370\040\157\003; } > arch/x86/boot/compressed/vmlinux. > bin.zst > > [ amdgpu.ko.zst ] > $ grep zstd build-log_6.10.1-1-amd64-clang18-kcfi.txt | grep '\-T0' | > grep amdgpu > zstd -T0 --rm -f -q > debian/linux-image-6.10.1-1-amd64-clang18-kcfi/lib/modules/6.10.1-1-amd64-clang18-kcfi/kernel/drivers/gpu/drm/amd/amdgpu/amdgpu.ko > > Here some numbers: > > [ Values in KiB ] > $ du -k amdgpu.ko* > 29264 amdgpu.ko > 5672 amdgpu.ko.zst <--- XXX: -T0 > 4264 amdgpu.ko.zst_T0-19 <--- XXX: -T0 -19 > 4260 amdgpu.ko.zst_T0-22 > 4308 amdgpu.ko.zst_T0-22-ultra > > $ time zstd -T0 -v amdgpu.ko > *** Zstandard CLI (64-bit) v1.5.6, by Yann Collet *** > Note: 2 physical core(s) detected > zstd: amdgpu.ko.zst already exists; overwrite (y/n) ? y > amdgpu.ko : 19.38% ( 28.6 MiB => 5.54 MiB, amdgpu.ko.zst) > > real 0m2,496s > user 0m0,448s > sys 0m0,064s > > $ time zstd -T0 -19 -v amdgpu.ko > *** Zstandard CLI (64-bit) v1.5.6, by Yann Collet *** > Note: 2 physical core(s) detected > amdgpu.ko : 14.56% ( 28.6 MiB => 4.16 MiB, amdgpu.ko.zst) > > real 0m22,821s > user 0m22,759s > sys 0m0,080s > > My wish is to use the zstd-option "-T0" (see vmlinux.bin.zst) everywhere. > > For CONFIG_MODULE_COMPRESS_ZSTD=y: Add compress-level = -19 > > NOTE: -22 w/ or w/o ultra has no big effect here and increases even > more build-time. > > What do you think? > > Thanks. > > Best regards, > -Sedat-