GRIM: Excessive save game scanning/checking wastes FPS

[raziel-]

ScummVM latest version (complete version information will follow once I'm back home)

I had, for a few months now, a problem with recurring FPS dropouts (from 60 down to 2 in worst case) in the intro of Grim Fandango (full game, classic, non-enhanced, no mods) and *only* with this game.
I thought it may be because of something in my OpenGL implementation at first, then the game/engine on it's own maybe, but i couldn't point a finger to anything obvious (switching the different renderes didn' t show anything either).

Today i let a file snooper run beside the intro and it caught a massive amount of file read/locks on the save states i have (and i have *a lot* - 930 files with approx. 63 MB).

07442 : ScummVM         : o.k. = ChangeFilePosition(0x18B3A2EA [Games:ScummVM/LucasArts/Grim Fandango/DATA000.LAB],12743680,OFFSET_BEGINNING) [21uS]
07443 : ScummVM         : o.k. = ChangeFilePosition(0x18B3A2EA [Games:ScummVM/LucasArts/Grim Fandango/DATA000.LAB],12747248,OFFSET_BEGINNING) [475uS]
07444 : ScummVM         : DIR  = ParentOfFH(0x18B3A2EA) "Games:ScummVM/LucasArts/Grim Fandango/DATA000.LAB" [57uS]
07445 : ScummVM         : o.k. = ExamineObject([FH] "DATA000.LAB") [47uS]
07446 : ScummVM         : o.k. = ExamineObject([SN] "saves") [242uS]
07447 : ScummVM         : o.k. = Lock("saves/",SHARED) [35uS]
07448 : ScummVM         : o.k. = Lock("saves/",SHARED) [197uS]
07449 : ScummVM         : o.k. = Lock("Tools:Games/ScummVM/saves/grimdialog.htm",SHARED) [73uS]
07450 : ScummVM         : o.k. = Open("Tools:Games/ScummVM/saves/grimdialog.htm",OLD) = [0x18B3A2EA] [181uS]
07451 : ScummVM         : o.k. = ExamineObject([FH] "grimdialog.htm") [44uS]
07452 : ScummVM         : FAIL = IsInteractive("Tools:Games/ScummVM/saves/grimdialog.htm")
07453 : ScummVM         : o.k. = IsFileSystem("Tools:") [39uS]
07454 : ScummVM         : o.k. = ExamineObject([FH] "grimdialog.htm") [38uS]
07455 : ScummVM         : o.k. = ExamineObject([FH] "grimdialog.htm") [157uS]
07456 : ScummVM         : o.k. = ChangeFilePosition(0x18B3A2EA [Tools:Games/ScummVM/saves/grimdialog.htm],2,OFFSET_BEGINNING) [45uS]
07457 : ScummVM         : o.k. = ChangeFilePosition(0x18B3A2EA [Tools:Games/ScummVM/saves/grimdialog.htm],0,OFFSET_BEGINNING) [26uS]
07458 : ScummVM         : o.k. = ExamineObject([FH] "grimdialog.htm") [147uS]
07459 : ScummVM         : DIR  = ParentOfFH(0x18B3A2EA) "Tools:Games/ScummVM/saves/grimdialog.htm" [49uS]
07460 : ScummVM         : o.k. = ExamineObject([FH] "grimdialog.htm") [182uS]
07461 : ScummVM         : o.k. = ExamineObject([SN] "saves") [113uS]
07462 : ScummVM         : o.k. = Lock("saves/",SHARED) [28uS]
07463 : ScummVM         : o.k. = Lock("saves/",SHARED) [27uS]
07464 : ScummVM         : o.k. = ExamineObject([SN] "saves") [272uS]
07465 : ScummVM         : o.k. = Lock("saves/",SHARED) [33uS]
07466 : ScummVM         : o.k. = Lock("saves/",SHARED) [51uS]
07467 : AmiDock         : o.k. = [exec] OpenDevice("timer.device",0,0x629237F0,0x00000000) = 0 [10uS]
07468 : ScummVM         : o.k. = ExamineObject([SN] "saves") [363uS]
07469 : ScummVM         : o.k. = Lock("saves/",SHARED) [126uS]
07470 : ScummVM         : o.k. = ObtainDirContext(ctx=0x5211F658  dflags=0x10094) = [0x5211F658] [53uS]
07471 : ScummVM         : o.k. = Lock("richardandalice.999",SHARED) [72uS]
07472 : AmiDock         : o.k. = [exec] OpenDevice("timer.device",0,0x629235B0,0x00000000) = 0 [9uS]
07473 : ScummVM         : o.k. = ExamineObject([LK] "richardandalice.999") [49uS]
07474 : ScummVM         : o.k. = Lock("grimlog00.htm",SHARED) [163uS]
07475 : AmiDock         : o.k. = [exec] OpenDevice("timer.device",0,0x629237F0,0x00000000) = 0 [8uS]
07476 : ScummVM         : o.k. = ExamineObject([LK] "grimlog00.htm") [28uS]
07477 : ScummVM         : o.k. = Lock("grim00.gsv",SHARED) [29uS]
07478 : ScummVM         : o.k. = ExamineObject([LK] "grim00.gsv") [28uS]
07479 : ScummVM         : o.k. = Lock("mythguff-win.000",SHARED) [28uS]
07480 : ScummVM         : o.k. = ExamineObject([LK] "mythguff-win.000") [28uS]
07481 : ScummVM         : o.k. = Lock("kq1agdi.999",SHARED) [29uS]
07482 : ScummVM         : o.k. = ExamineObject([LK] "kq1agdi.999") [28uS]
07483 : ScummVM         : o.k. = Lock("kq1agdi.998",SHARED) [29uS]
07484 : ScummVM         : o.k. = ExamineObject([LK] "kq1agdi.998") [28uS]
07485 : ScummVM         : o.k. = Lock("steam-336130.dat",SHARED) [29uS]
07486 : ScummVM         : o.k. = ExamineObject([LK] "steam-336130.dat") [133uS]
07487 : ScummVM         : o.k. = Lock("shardlight.999",SHARED) [29uS]
07488 : ScummVM         : o.k. = ExamineObject([LK] "shardlight.999") [28uS]
07489 : ScummVM         : o.k. = Lock("hitchhikersguidetothegalaxyremake.000",SHARED) [30uS]
07490 : ScummVM         : o.k. = ExamineObject([LK] "hitchhikersguidetothegalaxyremake.000") [29uS]
07491 : ScummVM         : o.k. = Lock("asecondface.999",SHARED) [29uS]
07492 : ScummVM         : o.k. = ExamineObject([LK] "asecondface.999") [29uS]
07493 : ScummVM         : o.k. = Lock("asecondface.000",SHARED) [29uS]

As you can see after loading the game and the intro starts, ScummVM starts to scan my saves/ dir...but why?
And why does it do that over and over again?
And why does it not simply look for the save states of the game that was run, instead of scanning *all* of them?
And why in the intro, it' s not like i could load or save a game there, shouldn't it scan the saves/ dir on start of ScummVM or while in the launcher?

Next step was to rename the saves/ drawer and starting the game once more...no more FPS dropouts whatsoever.

My question would be, could someone who knows the engine, please check what's going on there and maybe reduce the scan for save states et al or at least to Grim Fandango saves?
That would save me lots of FPS.

@sev suggested to add a trap, but I'd need a step per step guide to use something like that.

Thank you

Grim Fandango (Windows/English)

AmigaOS4 - BigEndian - PPC
gcc (adtools build 11.3.0) 11.3.0