On Wed, 17 Aug 2022 at 13:53, Arnd Bergmann <arnd@xxxxxxxx> wrote: > > On Wed, Aug 17, 2022 at 1:03 PM Ard Biesheuvel <ardb@xxxxxxxxxx> wrote: > > BZIP2 has been omitted from the set of supported compression algorithms, > > given that its performance is mediocre both in speed and size, and it > > uses a disproportionate amount of memory. For optimal compression, use > > LZMA. For the fastest boot speed, use LZO. > ... > > +config EFI_ZBOOT > > + bool "Enable the generic EFI decompressor" > > + depends on EFI_GENERIC_STUB && !ARM > > + select HAVE_KERNEL_GZIP > > + select HAVE_KERNEL_LZ4 > > + select HAVE_KERNEL_LZMA > > + select HAVE_KERNEL_LZO > > I hope I don't turn this into a bike-shed discussion, but it feels > like if you give > the choice between these four, you should also offer ZSTD, which combines > high compression ratio with fast decompression speed. > XZ is probably more widely installed than LZMA. > > I would be happy with just gzip (to minimize build dependencies) and > zstd, but there is little harm in also including the other ones you have > here, or all seven of them. > Let's add whatever people feel is useful. The reason I dropped bzip2 is because it uses much more memory. This is not a problem per se, but it seemed pointless to accommodate bzip2 if we have better options anyway. zstd seems trivial to add if i bump the heap size to 256k, and xz just needs a little tweak so it doesn't redefine memmove and memcpy, but beyond that, it's just copy/paste'ing the pattern another couple of times.
