[tlbuild] zstd as package compressor

[Henri Menke]

I installed pretest yesterday, so I thought I might as well run the
installation in nytprof.  The results are available here:

https://www.henrimenke.com/files/nytprof/index.html

For some reason Firefox refuses to display the flame graph inline and
Chrome says it doesn't support SVG.  If you just open the flame graph in
its own tab/window, it displays correctly though.

https://www.henrimenke.com/files/nytprof/all_stacks_by_time.svg

I haven't had a chance to look at the benchmark in detail yet, but it
looks like by far the most time is spent in TLUtils::download_file.  The
call to the decompressor and and untar take two orders of magnitude less
time.  So it seems to speed up TeX Live installation it is more
important to increase download throughput than uncompression throughput.

Of course this is kind of biased because I'm in New Zealand where the
internet is pretty bad and the closest pretest mirror is in the US, but
I don't think that a faster mirror would compensate the two orders of
magnitude.

Cheers, Henri

On 2/20/20 12:13 PM, Karl Berry wrote:
> FWIW, I've tried running tlmgr update with NYTProf
> (https://metacpan.org/pod/Devel::NYTProf)
> (as in /usr/local/bin/perl -d:NYTProf tlmgr.pl ...)
> I saw no especially low-hanging fruit :(.
> 
> Maybe someone would like to try running the installer that way
> and see if there is anything that jumps out. Or I will at some point,
> but not soon. --thanks, karl.
>