Cygwin malloc tune-up status

[Johannes Schindelin]

Hi Mark,

On Thu, 24 Sep 2020, Mark Geisert wrote:

> I've been looking into two potential enhancements of Cygwin's malloc operation
> for Cygwin 3.2.  The first is to replace the existing function-level locking
> with something more fine-grained to help threaded processes; the second is to
> implement thread-specific memory pools with the aim of lessening lock activity
> even further.
>
> Although I've investigated several alternative malloc packages, including
> ptmalloc[23], nedalloc, and Windows Heaps, only the latter seems to improve on
> the performance of Cygwin's malloc.  Unfortunately using Windows Heaps would
> require fiddling with undocumented heap structures to enable use with fork().
> I also looked at BSD's jemalloc and Google's tcmalloc.  Those two require much
> more work to port to Cygwin so I've back-burnered them for the time being.

I am just a lurker when it comes to your project, but I wonder whether you
had any chance to look into mimalloc
(https://github.com/microsoft/mimalloc)? I had investigated it in Git for
Windows' context for a while (because nedmalloc, which is used by Git for
Windows, is no longer actively maintained).

Ciao,
Dscho