[Mono-dev] large performance drop between boehm and sgen for a parallel app

[Jonathan Shore]

Hi,

I have a complex parallel application which, when run on 10 threads gets very close to 1000% cpu with mono-boehm (linux) consistently (running for hours).   With mono-sgen only achieves  200 - 250% cpu.   This is on a 12 / 24 core machine.   I need to run sgen eventually because run into the 32 bit limit with boehm from time to time.

Note that this is with a fairly recent version of mono compiled from git sources with llvm enabled.

It is not an application I can easily box up for analysis on bugzilla due to size of data context, though happy to provide an enviroment to the mono team if useful.  Wondering whether there is some GC debugging can turn on that is useful to the mono team?

Thanks
Jonathan