zram-swap: default to lzo instead of lzo-rle compression

[Sven Roederer]

Am Montag, 29. November 2021, 10:57:37 CET schrieb Rui Salvaterra:
> Hi, Sven,
> 
> On Sun, 28 Nov 2021 at 01:40, Sven Roederer <devel-sven at geroedel.de> wrote:
> > Rui, not sure if to call it a bug. At the end there is a hardcoded default
> > algo in the module, that is used initially when creating the device. The
> > check for the valid algo is done later at device-activation.
> > I spend some time in this code and have a patch ready, which checks for
> > algos before announcing them.
> 
> It's not a bug, but it's also not exactly an unsurprising behaviour.
> This is the real issue:
> 
> https://elixir.bootlin.com/linux/v5.10.82/source/crypto/Makefile#L153
> 
> obj-$(CONFIG_CRYPTO_LZO) += lzo.o lzo-rle.o
> 
> Even though they're built as separate modules, they depend on a single
> kconfig symbol. Moreover, lzo-rle uses most of the original lzo
> functions (adding just RLE on top), so they should arguably just be
> merged. I don't know how receptive upstream is to that idea, but it
> seems logical to me.
> 

Rui, 

during my work I also had the impression, that both files probably share a lot 
of common code. Based on your comment I had a closer look ...
Back in 2019 (v5.1) the linux guys explicitly split the code into separate 
files to avoid potential data-corrution. 
https://github.com/torvalds/linux/commit/45ec975efb527625629d123f305

So I don't expect joining the code again will be accepted upstream.

Back to the initial issue, I just send my patch of the selection-algorithm to 
the list for tests and comments.
When it's proven to work, I'm fine with trying to push upstream.

Sven