Unexpected performance drop [Corpse Party]

[Nabokov86]

Game or games this happens in

ULJM05704 - コープスパーティー ブラッドカバー リピーティッドフィアー

What area of the game

The game runs very fast, but sometimes there is a big drop in performance. Especially when you go from one location to another.
This causes the sound to stutter for a moment, which is annoying.

Speed seen in PPSSPP

With unlimited speed - 800%, when dropped - 30-60%.

GE frame capture and debug statistics

Platform

Android

Mobile phone model or graphics card

Mali-G31 GPU

PPSSPP version affected

v1.12.3-776-g1c18c172a
V1.12.3
V1.11.3
V1.10.3

Last working version

No response

Graphics backend (3D API)

OpenGL / GLES
Vulkan

Any other notes or things you've tried

I tried resetting the settings, tried other android devices, same issue.

Checklist

• Test in the latest git build in case it's already fixed.
• Search for other reports of the same issue.
• Try resetting settings or older versions and include if the issue is related.
• Try changing graphics settings to determine if one causes the slowdown.
• Include logs or screenshots of issue.

[Nabokov86]

These peaks occur every time you enter a different area.

[hrydgard]

Hm, those peaks look quite nasty indeed..

[unknownbrackets]

Do the same peaks, just with a presumably lower amplitude, occur on PC? I want to make sure this isn't IO related - I know Android recently made IO much slower.

It's interesting that LockLwMutex is so hot, it's probably some sort of tight loop, I guess. I don't think that has timings yet.

-[Unknown]

[Nabokov86]

@unknownbrackets The desktop computer handles it better, but I think the peaks are relatively the same.

And with unlimited speed:

[hrydgard]

@Nabokov86 Does it work better in the latest builds (829, for example?)

[Nabokov86]

@hrydgard It looks the same, no difference

Oh, no! It definitely got better!

[Nabokov86]

Look at this!

Android:

[hrydgard]

Still not great, but looks better indeed! Do you still get audio glitches?

I wonder if this happens to any degree on the real PSP, or if there are more related timing issues somehow.

[Nabokov86]

@hrydgard Audio glitches are still present, but they are shorter and much less annoying.

Still sometimes the sound is noticeably interrupted, especially in certain areas.

[unknownbrackets]

Do the debug statistics show anything different now?

-[Unknown]

[Nabokov86]

@unknownbrackets No :(

[unknownbrackets]

Strange. I'd be less surprised if sceAtracDecodeData was maybe the cuplrit, but I wonder why it's locking mutexes enough that it's noticeably slow... I wonder if unlock is just behind it in slowness...?

When #15368 is merged, it may be easier to catch these blips using frame advance, and especially see if there's interesting stats right before or right after. I'm also interested in whether the time taken is significantly different when frame advancing.

-[Unknown]

[Nabokov86]

@unknownbrackets I apologize for the late response.

#15368 is merged, right?
I can't find the frame advance option. Could you please help me with that?

[unknownbrackets]

You can map a button in control mapping to frame advance. Then when you press that button, it will pause, and you can keep pressing it to step forward one frame at a time. To stop frame advance, press whatever button is mapped to fast-forward.

-[Unknown]

[Nabokov86]

@unknownbrackets Thanks for the quick reply!

Checked twice, I definitely don't have that button. Could this option be unavailable on android?
I will try it on Windows later.

[Nabokov86]

@unknownbrackets Yes, frame advance is not available on android.

I recorded two videos: using frame advance and 5% speed. The result is quite different.

5% speed:
https://user-images.githubusercontent.com/26260168/152365423-6d69079d-c202-4f1a-9dcf-c82da5a703d5.mp4
Here you can clearly see the lag and LockLwMutexCB.

Frame advance:
https://user-images.githubusercontent.com/26260168/152367211-570ae50b-dbf8-442e-a191-459d4eb96cf5.mp4

Hope this will be useful.

[Nabokov86]

Android:

Android_debug.mp4

[unknownbrackets]

Has anything improved in the very latest git builds? We made another change, which might help.

-[Unknown]

[Nabokov86]

@unknownbrackets No, nothing.

[unknownbrackets]

There was another recent change, has this improved on Android?

-[Unknown]

[Nabokov86]

@unknownbrackets Same, nothing has changed :(

Peaks on the graph look the same. A very short image lag is noticeable during peaks as before. ULJM05704_00059

[Nabokov86]

In other locations there are even bigger peaks.

[Nabokov86]

I discovered a new thing. Bluetooth-friendly buffer reduces audio glitches a lot in this game.

[hrydgard]

Yeah well that means that we still have stalls, just that the buffer is large enough with that setting to cover for it..

[unknownbrackets]

I have been thinking of putting atrac decode on a thread, which might help this. I suspect the game is decoding the entire background music for the next area during the scene transition.

-[Unknown]

[Nabokov86]

I suspect the game is decoding the entire background music for the next area during the scene transition

I don't think so. The background music does not change during scene transitions.

For example, there is a dead end in this scene. The background music does not change, there seems to be no new sounds at all. The only new content is textures and a text note. The textures are loaded before this peak on the graph. Every time you enter this location causes this. Looks like something is loaded/decoded every time for this particular scene.

[ghost]

Cache full ISO in RAM doesn't help this if you enable?

[Nabokov86]

@EternalsDarkhole No, it didn't help.

[ghost]

Can you upload save state of this area/stage of this game where it lag.

[Nabokov86]

@EternalsDarkhole Sure.

1. ULJM05704_1.03_0.zip Go up here.
2. ULJM05704_1.03_1.zip Go left here.

It lags almost everywhere more or less, though.

[ghost]

@EternalsDarkhole Sure.

1. ULJM05704_1.03_0.zip Go up here.
2. ULJM05704_1.03_1.zip Go left here.

It lags almost everywhere more or less, though.

Thanks!
BTW is NPUH-10117 is the usa version?

[Nabokov86]

NPUH-10117 is the usa version

Yeah, I think so. But I have the Japanese version ULJM-05704

[ghost]

Android:

Android_debug.mp4

I cannot reproduce this kind of issue on the usa version of this game on my phone using ppsspp latest build.

Screenrecorder-2022-04-13-20-50-46-65.mp4

[ghost]

Maybe this issue is similar to KoF Orochi Collection #12543 where the USA version is smooth while the JAP version is slow.

[Nabokov86]

Yes, I confirm. Looks like it's only related to the Japanese version.

NPUH-10117:

[ghost]

Yes, I confirm. Looks like it's only related to the Japanese version.

NPUH-10117:

Can you try software rendering?