performance problems

Fri Aug 13 11:59:00 GMT 1999

>>>>> "Jeff" == Jeff Sturm <jsturm@sigma6.com> writes:

Jeff> I compiled the benchmark code with -O3, I think... I also
Jeff> hacked the GC initialization code to bump the initial heap up to
Jeff> 16MB. I should probably send a patch for it. Does anyone
Jeff> object to an environment variable, something like GCJ_HEAP_INIT,
Jeff> to set the initial heap size?
I'm not too thrilled with the idea of an environment variable.
Shouldn't this be set on a per-application basis?
Two ideas:
1. Change the default in the Boehm GC on a per-target basis.
 For native builds we could make it larger.
2. Add a new --heap-size option to gcj and build in the number
 at link time. Change the GC interface (such as it is) in libgcj
 to support setting this at initialization time.
Comments?
I don't have time to implement either one :-(
Jeff> Any other thread trying to enter the monitor is going to
Jeff> busy-loop at least until the I/O completes, potentially a very
Jeff> long time.
This seems like a problem in LinuxThreads. Busy-waiting is bad, and
there's no rule that says you should only hold a mutex for a short
period of time.
Tom