Hello. On Wed, Mar 31, 2021 at 07:21:07PM +0000, Nick Terrell wrote: > > > > On Mar 31, 2021, at 10:48 AM, Oleksandr Natalenko > > <oleksa...@natalenko.name> wrote: > > > > Hello. > > > > On Wed, Mar 31, 2021 at 05:39:25PM +0000, Nick Terrell wrote: > >> > >> > >>> On Mar 30, 2021, at 4:50 AM, Oleksandr Natalenko > >>> <oleksa...@natalenko.name> wrote: > >>> > >>> On Tue, Mar 30, 2021 at 01:32:35PM +0200, Piotr Gorski wrote: > >>>> kmod 28 supports modules compressed in zstd format so let's add this > >>>> possibility to kernel. > >>>> > >>>> Signed-off-by: Piotr Gorski <lucjan.lucja...@gmail.com> > >>>> --- > >>>> Makefile | 7 +++++-- > >>>> init/Kconfig | 9 ++++++--- > >>>> 2 files changed, 11 insertions(+), 5 deletions(-) > >>>> > >>>> diff --git a/Makefile b/Makefile > >>>> index 5160ff8903c1..82f4f4cc2955 100644 > >>>> --- a/Makefile > >>>> +++ b/Makefile > >>>> @@ -1156,8 +1156,8 @@ endif # INSTALL_MOD_STRIP > >>>> export mod_strip_cmd > >>>> > >>>> # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed > >>>> -# after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP > >>>> -# or CONFIG_MODULE_COMPRESS_XZ. > >>>> +# after they are installed in agreement with > >>>> CONFIG_MODULE_COMPRESS_GZIP, > >>>> +# CONFIG_MODULE_COMPRESS_XZ, or CONFIG_MODULE_COMPRESS_ZSTD. > >>>> > >>>> mod_compress_cmd = true > >>>> ifdef CONFIG_MODULE_COMPRESS > >>>> @@ -1167,6 +1167,9 @@ ifdef CONFIG_MODULE_COMPRESS > >>>> ifdef CONFIG_MODULE_COMPRESS_XZ > >>>> mod_compress_cmd = $(XZ) --lzma2=dict=2MiB -f > >>>> endif # CONFIG_MODULE_COMPRESS_XZ > >>>> + ifdef CONFIG_MODULE_COMPRESS_ZSTD > >>>> + mod_compress_cmd = $(ZSTD) -T0 --rm -f -q > >> > >> This will use the default zstd level, level 3. I think it would make more > >> sense to use a high > >> compression level. Level 19 would probably be a good choice. That will > >> choose a window > >> size of up to 8MB, meaning the decompressor needs to allocate that much > >> memory. If that > >> is unacceptable, you could use `zstd -T0 --rm -f -q -19 --zstd=wlog=21`, > >> which will use a > >> window size of up to 2MB, to match the XZ command. Note that if the file > >> is smaller than > >> the window size, it will be shrunk to the smallest power of two at least > >> as large as the file. > > > > Please no. We've already done that with initramfs in Arch, and it > > increased the time to generate it enormously. > > > > I understand that building a kernel is a more rare operation than > > regenerating initramfs, but still I'd go against hard-coding the level. > > And if it should be specified anyway, I'd opt in for an explicit > > configuration option. Remember, not all the kernel are built on > > build farms... > > > > FWIW, Piotr originally used level 9 which worked okay, but I insisted > > on sending the patch initially without specifying level at all like it is > > done for other compressors. If this is a wrong approach, then oh meh, > > mea culpa ;). > > > > Whatever default non-standard compression level you choose, I'm fine > > as long as I can change it without editing Makefile. > > That makes sense to me. I have a deep seated need to compress files as > efficiently as possible for widely distributed packages. But, I understand > that > slow compression significantly impacts build times for quick iteration. I’d be > happy with a compression level parameter that defaults to a happy middle. > > I’m also fine with taking this patch as-is if it is easier, and I can put up > another > patch that adds a compression level parameter, since I don’t want to block > merging this.
Well, it seems Andrew already took this into his tree, so feel free to drop another one on top of that! > > Best, > Nick Terrell > > > Thanks! > > > >> > >> Best, > >> Nick Terrell > >> > >>>> + endif # CONFIG_MODULE_COMPRESS_ZSTD > >>>> endif # CONFIG_MODULE_COMPRESS > >>>> export mod_compress_cmd > >>>> > >>>> diff --git a/init/Kconfig b/init/Kconfig > >>>> index 8c2cfd88f6ef..86a452bc2747 100644 > >>>> --- a/init/Kconfig > >>>> +++ b/init/Kconfig > >>>> @@ -2250,8 +2250,8 @@ config MODULE_COMPRESS > >>>> bool "Compress modules on installation" > >>>> help > >>>> > >>>> - Compresses kernel modules when 'make modules_install' is run; > >>>> gzip or > >>>> - xz depending on "Compression algorithm" below. > >>>> + Compresses kernel modules when 'make modules_install' is run; > >>>> gzip, > >>>> + xz, or zstd depending on "Compression algorithm" below. > >>>> > >>>> module-init-tools MAY support gzip, and kmod MAY support gzip and xz. > >>>> > >>>> @@ -2273,7 +2273,7 @@ choice > >>>> This determines which sort of compression will be used during > >>>> 'make modules_install'. > >>>> > >>>> - GZIP (default) and XZ are supported. > >>>> + GZIP (default), XZ, and ZSTD are supported. > >>>> > >>>> config MODULE_COMPRESS_GZIP > >>>> bool "GZIP" > >>>> @@ -2281,6 +2281,9 @@ config MODULE_COMPRESS_GZIP > >>>> config MODULE_COMPRESS_XZ > >>>> bool "XZ" > >>>> > >>>> +config MODULE_COMPRESS_ZSTD > >>>> + bool "ZSTD" > >>>> + > >>>> endchoice > >>>> > >>>> config MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS > >>>> -- > >>>> 2.31.0.97.g1424303384 > >>>> > >>> > >>> Great! > >>> > >>> Reviewed-by: Oleksandr Natalenko <oleksa...@natalenko.name> > >>> > >>> This works perfectly fine in Arch Linux if accompanied by the > >>> following mkinitcpio amendment: [1]. > >>> > >>> I'm also Cc'ing other people from get_maintainers output just > >>> to make this submission more visible. > >>> > >>> Thanks. > >>> > >>> [1] https://github.com/archlinux/mkinitcpio/pull/43 > >>> > >>> -- > >>> Oleksandr Natalenko (post-factum) > >> > > > > -- > > Oleksandr Natalenko (post-factum) > -- Oleksandr Natalenko (post-factum)
