64 bit Cygwin 1.7.18-18

[Corinna Vinschen]

Hi kiddies,


I just uploaded the 64 bit cygwin 1.7.18-18 package.  About 4 weeks ago
I ripped out ptmalloc3.  The reason was ptmalloc3 always used mmap.
Duplicating many mmaps at fork time is noticably less performant than
duplicating the heap, so I thought ptmalloc3 is not useful for us.

However, I investigated this again today, and it turned out that my
assumption was based on some default settings, which I didn't quite
understood at the time (dlmalloc has lots of intertwined settings).

I now reinstantiated ptmalloc3 in the 64 bit branch again, this time
with a tweak which lets ptmalloc3 prefer heap memory over mmap'ed
memory.  It seems to work nicely, at least a complete configure/make
of lynx worked as designed.

Ultimately we might switch to jemalloc(*) at one point, but for the time
being, ptmalloc3 seems to be a nice compromise, given how much faster it
is in a multi-threaded environment.

So, please test.  If you see that anything is reproducibly broken, just
by updating from 1.7.18-17 to 1.7.18-18, please report it here.


Thanks,
Corinna

(*) http://www.canonware.com/jemalloc/


-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat