Re: Read before you deploy btrfs + zstd

[Martin Steigerwald <martin@lichtvoll.de>]

David Sterba - 15.11.17, 15:39:
> On Tue, Nov 14, 2017 at 07:53:31PM +0100, David Sterba wrote:
> > On Mon, Nov 13, 2017 at 11:50:46PM +0100, David Sterba wrote:
> > > Up to now, there are no bootloaders supporting ZSTD.
> > 
> > I've tried to implement the support to GRUB, still incomplete and hacky
> > but most of the code is there.  The ZSTD implementation is copied from
> > kernel. The allocators need to be properly set up, as it needs to use
> > grub_malloc/grub_free for the workspace thats called from some ZSTD_*
> > functions.
> > 
> > https://github.com/kdave/grub/tree/btrfs-zstd
> 
> The branch is now in a state that can be tested. Turns out the memory
> requirements are too much for grub, so the boot fails with "not enough
> memory". The calculated value
> 
> ZSTD_BTRFS_MAX_INPUT: 131072
> ZSTD_DStreamWorkspaceBound with ZSTD_BTRFS_MAX_INPUT: 549424
> 
> This is not something I could fix easily, we'd probalby need a tuned
> version of ZSTD for grub constraints. Adding Nick to CC.

Somehow I am happy that I still have a plain Ext4 for /boot. :)

Thanks for looking into Grub support anyway.

Thanks,
-- 
Martin