p.s. Trying again and using "View | Log", and letting it run a longer time. At first, still just tiny jitters. Then I hit two major GCs, each of which were obviously quite noticeable:
GC: 0:min @ 371,081K(+-44,377K)[+28,568K]; free 25,584K(-25,584K) 16ms @ 68466 GC: 0:min @ 378,376K(+-51,672K)[+28,592K]; free 29,628K(-29,628K) 13ms @ 69192 GC: 0:min @ 381,597K(+-54,893K)[+28,588K]; free 31,009K(-31,009K) 8ms @ 69930 GC: 0:min @ 383,394K(+-56,690K)[+28,588K]; free 30,956K(-30,956K) 9ms @ 70715 GC: 0:min @ 385,224K(+-58,520K)[+28,588K]; free 28,722K(-28,722K) 8ms @ 71499 GC: 0:min @ 389,286K(+-62,582K)[+28,588K]; free 30,072K(-30,072K) 8ms @ 72219 GC: 0:min @ 392,017K(+-65,313K)[+28,588K]; free 30,095K(-30,095K) 7ms @ 72938 GC: 0:min @ 394,711K(+-68,007K)[+28,588K]; free 30,044K(-30,044K) 7ms @ 73759 GC: 0:min @ 397,468K(+-70,764K)[+28,588K]; free 30,059K(-30,059K) 8ms @ 74500 GC: 0:min @ 400,196K(+-73,492K)[+28,588K]; free 30,049K(-30,049K) 7ms @ 75310 GC: 0:min @ 402,932K(+-76,228K)[+28,588K]; free 30,069K(-30,069K) 9ms @ 76058 GC: 0:MAJ @ 405,652K(+-78,948K)[+28,588K]; free 196,329K(-196,329K) 548ms @ 76883 GC: 0:MAJ @ 242,109K(+84,594K)[+28,476K]; free 47,896K(-39,144K) 491ms @ 78139 GC: 0:min @ 226,994K(+90,957K)[+28,472K]; free 29,742K(-29,742K) 10ms @ 79233 GC: 0:min @ 230,034K(+87,917K)[+28,472K]; free 31,030K(-31,030K) 6ms @ 79926 GC: 0:min @ 231,803K(+86,148K)[+28,472K]; free 29,749K(-29,749K) 8ms @ 80613 GC: 0:min @ 234,835K(+83,116K)[+28,472K]; free 31,011K(-31,011K) 8ms @ 81294 This in DrRacket. Robby's suggestion to run command-line is better idea since it takes DrRacket itself out of the mix. On Wed, Aug 7, 2013 at 8:04 PM, Greg Hendershott <greghendersh...@gmail.com> wrote: > I didn't get any noticeable jitter. Noticed I had "Racket | Limit > Memory..." set to 2048 MB. > > I reduced it to 64 MB. Still no jitter. > > I cranked it down to 8 MB (the minimum). Then I got some jitter. Not > extreme, but noticeable. > > The variance in people's reported experiences might be due (partly) to that? > > > On Wed, Aug 7, 2013 at 6:16 PM, Carl Eastlund <c...@ccs.neu.edu> wrote: >> For reference, I was on IRC with Jack when he first ran into this, and >> reproduced the jittery behavior on my own machine with a freshly started >> DrRacket. The first time I ran the program, and perhaps every 10th time I >> ran it, it would hiccup briefly within a second of hitting run, then run >> smoothly. This is on a relatively recent Mac Mini with 16 GB RAM, 4 >> physical / 8 virtual cores, and little else running at the time. >> >> Carl Eastlund >> >> On Wed, Aug 7, 2013 at 5:22 PM, Robby Findler <ro...@eecs.northwestern.edu> >> wrote: >>> >>> I just tried this on my mac (a fairly recent machine but not a super-duper >>> powerhouse) and it didn't seem jittery. >>> >>> What happens if you save it in "file.rkt" and, from a terminal window, run >>> "racket file.rkt"? Here's the precise command I ran (on a mac): >>> >>> /Applications/Racket\ v5.3.5/bin/racket -W debug@GC ~/file.rkt >>> >>> I didn't see too many GCs once the game started and the ones I saw were >>> unlikely to be noticeable (they were 3-5 msec; well below the 16 msec screen >>> refresh rate). >>> >>> If that makes a difference on your machine, perhaps that means it is time >>> to restart DrRacket (as GCs can take significantly longer for programs >>> running inside DrRacket, esp. if there is a leak somewhere). >>> >>> Robby >>> >>> >>> On Wed, Aug 7, 2013 at 2:58 AM, Robby Findler >>> <ro...@eecs.northwestern.edu> wrote: >>>> >>>> Well, allocation is what triggers GC and there appears to be a fair >>>> amount of that in your program. I am not in a good position to run your >>>> code >>>> and nothing jumps out at me from a first glance at the gist but probably it >>>> is allocation that originates there (not that that >>>> means your code is necc. buggy). >>>> >>>> Fundamentally, functional image construction (and lists) requires >>>> allocation and allocation requires GC. That said there is probably >>>> something's we can fix here. I will try to take a closer look in the coming >>>> days of no one beats me to it. >>>> >>>> Robby >>>> >>>> >>>> On Wednesday, August 7, 2013, Jack Firth wrote: >>>>> >>>>> Hey users, I'm experimenting with some simple games using big-bang from >>>>> 2htdp/universe and I keep running into stuttering problems. It seems to be >>>>> the garbage collector slowing things down (green recycle symbol in >>>>> drracket >>>>> is on whenever the program is frozen). >>>>> >>>>> Increasing the memory limit or removing the limit altogether doesn't >>>>> seem to affect the problem, and I've checked in the IRC and it occurs on >>>>> other machines as well, all of which have the specs that it shouldn't have >>>>> any problems with slowdown. Are there issues with big-bang and it's event >>>>> handling? >>>>> >>>>> Source - https://gist.github.com/Universalist235/6171371 >>> >>> >>> >>> ____________________ >>> Racket Users list: >>> http://lists.racket-lang.org/users >>> >> >> >> ____________________ >> Racket Users list: >> http://lists.racket-lang.org/users >> ____________________ Racket Users list: http://lists.racket-lang.org/users
