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.