Re: Cygwin multithreading performance

["John Hein" <3fbmqnhaz4 at snkmail dot com>]

Mark Geisert wrote at 23:45 -0800 on Nov 22, 2015:
 > Corinna Vinschen wrote:
 > > On Nov 21 01:21, Mark Geisert wrote:
 > [...] so I wonder if there's
 > >> some unintentional serialization going on somewhere, but I don't know yet
 > >> how I could verify that theory.
 > >
 > > If I'm allowed to make an educated guess, the big serializer in Cygwin
 > > are probably the calls to malloc, calloc, realloc, free.  We desperately
 > > need a new malloc implementation better suited to multi-threading.
 > 
 > That's very helpful to know.  I'd want to first make sure the heavy lock 
 > activity I'm seeing in the traces really is due to malloc() and friends 
 > but I couldn't help a speculative search online for multithread-safe 
 > malloc().  These turned up:
 >      tcmalloc - part of google-perftools, requires libunwind, evidently 
 > not yet ported to Windows AFAICT,
 >      nedmalloc - http://www.nedprod.com/programs/portable/nedmalloc/
 >      ptmalloc - http://www.malloc.de/
 > 
 > The latter two are based on Doug Lea's dlmalloc which is also the basis 
 > of Cygwin's malloc() functions.  As I understand it, ptmalloc in one 
 > form or another has been part of glibc on Linux for some time.
 > 
 > So there may be a solution in sight if we need to go that direction.  Of 
 > course, SHTDI as usual :).
 > 
 > ...mark

Someone recently mentioned on this list they were working on porting
jemalloc.  That would be a good choice.

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