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-
