On Thu, 28 Mar 2002, John M McIntosh wrote:

> I'll just cherry pick the easy ones.
>
> >On Sat, 16 Mar 2002, PhiHo Hoang wrote:
> >
> >>  My only concern was that how were the numbers arrived at for things
> >>  like:
> >
> >  >		int atCache[65];
> >
> >AFAIK, This is an optimization; it doesn't affect correctness.  But,
> >experimentation for different sizes might be fruitful.  Anyone know how
> >much the atCache affects the runtime? I may get a chance to look at it.
>

I presume here you're talking about the methodCache, not the atCache?

> A year ago I looked at this and from a note I sent to Dan I'll quote:
> "I noted that in lookupInMethodCacheSelclass, the number of calls was
> about 50 million,and cache hits: 20M on probe1, 16M on probe2, 11M on
> probe3 and 1.8M not found

Thats roughtly what I saw.. The new methodcache superseeds this, with a
much better overall hit rate, and a much better hit-rate for the first
probe.

>
> BTW I looked at atCache, but mmm 'since objects die young' found that
> over 70% of the at cache would be flushed at any given incremental GC
> event. (IE 70% of the time objects were in new space)."
>

Interesting, what about if someone changes GC parameters so that incrGC's
happen a lot less often (by, say, making 100,000 allocs/incrgc). Then,
doubling or quadrupling this might have a useful effect... Flushing even
32 (4x as many) entries is inconsequential compared to the methodCache
which has 512, much less the cost of the incrGC.

I should study the design and consider increasing the size.


> >
> >  >		int semaphoresToSignalA[501];
> >>		int semaphoresToSignalB[501];
> >
> >Dunno about these. Would these be a limit on the maximum number of open
> >sockets?
>
> This is my change a few years back.

> on. So can you signal more than  500 interrupts in 1 to 3ms?

Ok.. Excellent.. I just saw a semaphore-related limit and wondered if it
created a limit on total number of semaphores. It doesn't.. Thanks.



Scott


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