Hi John -

John M McIntosh wrote:
> It also btw had code in SophieMemoryPolicy >>calculateGoals that 
> adjusted Smalltalk vmParameterAt: 5 and 6 to target a 1 ms incremental 
> GC time. A singleton instance wakes up every 5 seconds and peeks at the 
> GC statistical data. However I've not been doing this adjustment.

I'm actually more shooting for 5ms IGC times but having a process which 
tweaks these parameters is an interesting idea too.

> I used Smalltalk gcBiasToGrowLimit:  32MB since that seemed to be a 
> reasonable value for doing minor amounts of user interaction when I last 
> looked at it, and I just doubled the vmParms 5/6  which as you point out 
> is inadequate.

Right. Our allocation patterns are more agressive than your average 
Squeak image though, so simply doubling it was not enough (but even 
increasing it by ten didn't have any ill effects on IGC speed).

> I'll lastly note you must apply JMM-fixBiasToGrow.1.cs to your VMMaker 
> image to ensure the "growSize :=  growHeadroom*3/2 - (self sizeOfFree: 
> freeBlock)." has the missing period
> otherwise as noted earlier this year then the entire statement is 
> dropped by SLANG and then causes the bias to grow logic to work 
> incorrectly.  I don't believe Tim has added this
> fix to VMMaker yet?

Oh! I hadn't noticed that. I'll fix it in my copy right away, thanks for 
pointing it out.

Cheers,
   - Andreas