Re: zlib-ng as a compat replacement for zlib

[Richard W.M. Jones]

On Fri, Sep 01, 2023 at 11:06:20AM +0100, Daniel P. Berrangé wrote:
> On Fri, Sep 01, 2023 at 11:03:54AM +0100, Richard W.M. Jones wrote:
> > I forgot to say that nbdkit is using zlib-ng, since I made the source
> > level changes a few weeks back (but most of the nbdkit performance
> > improvement comes from being able to use lots of threads).
> 
> Ah that last point is interesting. If we look at nbdkit results we can
> see that while zstd is clearly faster, the margin of the win is massively
> lower. So I presume we can infer similar margins if qemu-img were
> switched too.

FWIW here's the nbdkit commit which added zlib-ng support (assuming
you don't want to wait for a compat package).  It's not a massive
change so something similar might be done for qemu:

https://gitlab.com/nbdkit/nbdkit/-/commit/1b67e323e998a5d719f1afe43d5be84e45c6739b

Rich.

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