[tex-live] Request for performance check of legacy darwin (luatex)

[Reinhard Kotucha]

On 2018-03-08 at 14:38:13 +0100, jfbu wrote:
 > $ time luatex temptest.tex
 > This is LuaTeX, Version 1.0.4 (TeX Live 2017/MacPorts 2017_1) 
 >  restricted system commands enabled.
 > (./temptest.tex . . . . . . . . . .)
 > warning  (pdf backend): no pages of output.
 > Transcript written on temptest.log.
 > 
 > real	0m1.745s
 > user	0m1.716s
 > sys	0m0.025s
 > 
 > $ time luatex temptest.tex
 > This is LuaTeX, Version 1.07.0 (TeX Live 2018) 
 >  restricted system commands enabled.
 > (./temptest.tex . . . . . . . . . .)
 > warning  (pdf backend): no pages of output.
 > Transcript written on temptest.log.
 > 
 > real	0m2.618s
 > user	0m2.593s
 > sys	0m0.020s

Just for the record, these numbers are meaningless if you don't clear
the filesystem cache before each run.

When I do

  time cat somefile > /dev/null

then the file is read from the disk with abt. 150 MB/s.

When I run the same command again, the file is read from the
filesystem cache with 8.5 GB/s.

In order to get comparable results it's necessary to wipe out the
cache before running any tests.  The easiest way to accomplish this on
Linux (at least) is to run the command

  sync; echo 3 > /proc/sys/vm/drop_caches

as root.  If you have a system monitor installed on your system
(xosview, for instance), you can see immediately what happens.

Regards,
  Reinhard

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Reinhard Kotucha                            Phone: +49-511-3373112
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