Re: EXT: Re: [OE-core] [PATCH V2] archiver: Configurable tarball compression

["Ian Ray" <ian.ray@ge.com>]

On Tue, Sep 21, 2021 at 03:48:29PM +0200, Michael Opdenacker wrote:
> 
> On 9/21/21 3:20 PM, Michael Opdenacker wrote:
> > By the way, zstd seems to be marginally worse (+1%) than xz in terms of
> > compressed size, but is orders of magnitude faster (see
> > https://archlinux.org/news/now-using-zstandard-instead-of-xz-for-package-compression/).
> 
> 
> Actually, this article only mentions decompression speed, but that's
> also true for compression speed.
> 
> Here are my own tests:
> 
> mike@mike-laptop:~/tmp$ time gzip linux-5.15-rc2.tar
> 
> real    0m29.293s
> user    0m28.712s
> sys    0m0.553s
> 
> mike@mike-laptop:~/tmp$ time xz linux-5.15-rc2.tar
> 
> real    7m2.658s
> user    7m1.096s
> sys    0m1.280s
> 
> mike@mike-laptop:~/tmp$ time zstd linux-5.15-rc2.tar
> linux-5.15-rc2.tar   : 16.29%   (1136803840 => 185233271 bytes,
> linux-5.15-rc2.tar.zst)
> 
> real    0m5.476s
> user    0m5.530s
> sys    0m0.864s
> 
> mike@mike-laptop:~/tmp$ ls -la linux-5.15*
> -rw-rw-r-- 1 mike mike 1136803840 Sep 21 15:31 linux-5.15-rc2.tar
> -rw-rw-r-- 1 mike mike  198135832 Sep 21 15:24 linux-5.15-rc2.tar.gz
> -rw-rw-r-- 1 mike mike  125980548 Sep 21 15:26 linux-5.15-rc2.tar.xz
> -rw-rw-r-- 1 mike mike  185233271 Sep 21 15:31 linux-5.15-rc2.tar.zst
> 
> So, here the claim that zstd (with default options) is almost as good as
> xz in compressed size is not confirmed. However, zstd is a clear winner
> in terms of compression speed, and anyway better than gzip. This is
> worth switching.

Thank you for measuring this!  

I will re-submit the patch when we update to a more recent Yocto
version.


> 
> Cheers
> 
> Michael
> 
> -- 
> Michael Opdenacker, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com
> 
>