Re: should GNU install call matchpathcon by default?

[Ondrej Vasik]

Jim Meyering <jim <at> meyering.net> writes:
> In the multi-file case, the pre-patch performance penalty for enabling
> the ifdef'd-out code would range from probably-immeasurable (for just
> 2 or 3 files) to infinite, with enough files to make install exhaust
> virtual memory.

Actually even for 2-3 files (copied to /usr/temp dir) it was measurable. 
On my machine the performance impact is following:
Setdefaultcontext code if0'd:                      0.0148 s.
Current patch(matchpathcon_init_prefix just once): 0.0666 s.
Old setdefaultcontext code:                        0.1702 s.

For 100 files(copied to /usr/temp) it took 4.0342 s. - that's about 35,5 times
more than with current patch from Jim and 128 times more than with if0'd
setdefaultcontext code. And of course for more files it goes to infinity.

Problem is that disabled code is causing bugzilla tickets like
https://bugzilla.redhat.com/show_bug.cgi?id=319231 , so maybe the best solution
to reduce performance impact would be to patch automake to install multiple
files in one directory at once or something like that - to reduce performance
impact of the ifdefed code on installation of big portions of files.