Re: zlib-ng as a compat replacement for zlib

[Richard W.M. Jones]

On Fri, Sep 01, 2023 at 10:42:16AM +0100, Richard W.M. Jones wrote:
> Results:
> 
>   Cluster  Compression  Compressed size  Prog   Decompression speed
> 
>   4k       zlib         3228811264       qemu   5.921 s ±  0.074 s
>   4k       zstd         3258097664       qemu   5.189 s ±  0.158 s
> 
>   4k       zlib/zstd                     nbdkit failed, bug!!

Stupid bounds checking bug, fixed now [1]:

    4k       zlib         3228811264       nbdkit 1.390 s ±  0.094 s
    4k       zstd         3258097664       nbdkit 1.328 s ±  0.055 s

>   64k      zlib         3164667904       qemu   3.579 s ±  0.094 s
>   64k      zstd         3132686336       qemu   1.770 s ±  0.060 s
> 
>   64k      zlib         3164667904       nbdkit 1.254 s ±  0.065 s
>   64k      zstd         3132686336       nbdkit 1.315 s ±  0.037 s
> 
>   512k     zlib         3158744576       qemu   4.008 s ±  0.058 s
>   512k     zstd         3032697344       qemu   1.503 s ±  0.072 s
> 
>   512k     zlib         3158744576       nbdkit 1.702 s ±  0.026 s
>   512k     zstd         3032697344       nbdkit 1.593 s ±  0.039 s
> 
>   2048k    zlib         3197569024       qemu   4.327 s ±  0.051 s
>   2048k    zstd         2995143168       qemu   1.465 s ±  0.085 s
> 
>   2048k    zlib         3197569024       nbdkit 3.660 s ±  0.011 s
>   2048k    zstd         2995143168       nbdkit 3.368 s ±  0.057 s

[1] 
https://gitlab.com/nbdkit/nbdkit/-/commit/73b58dc13dd7a3bbc7e7b3b718a535ee362caa92

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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