Re: PPC440 tlbwe

[Marek Glogowski]

HI

I am uploading the test results. It appears to be working very well. The system 
seems to work better. No additional problems.

  
—————————
— patched version qemu
—————————
2.AmigaOS:test> mplayer -vo null -ao null -benchmark "sys:Tools/Media/Danny and 
Stephen Fellner/AmigaOS.mpg"
MPlayer 1.5 SVN-r38423-snapshot (C) 2000-2023 MPlayer Team

Playing sys:Tools/Media/Danny and Stephen Fellner/AmigaOS.mpg.
libavformat version 60.3.100 (internal)
MPEG-PS file format detected.
VIDEO:  MPEG2  640x320  (aspect 1)  25.000 fps    0.0 kbps ( 0.0 kbyte/s)
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
libavcodec version 60.3.100 (internal)
Selected video codec: [ffmpeg2] vfm: ffmpeg (FFmpeg MPEG-2)
==========================================================================
Load subtitles in sys:Tools/Media/Danny and Stephen Fellner/
==========================================================================
Opening audio decoder: [mpg123] MPEG 1.0/2.0/2.5 layers I, II, III
AUDIO: 48000 Hz, 2 ch, s16be, 224.0 kbit/14.58% (ratio: 28000->192000)
Selected audio codec: [mpg123] afm: mpg123 (MPEG 1.0/2.0/2.5 layers I, II, III)
==========================================================================
 

BENCHMARKs: VC:  52.254s VO:   0.098s A:   6.311s Sys:   4.181s =   62.845s
BENCHMARK%: VC: 83.1476% VO:  0.1565% A: 10.0422% Sys:  6.6537% = 100.0000%

—————————
— org qemu
—————————
2.AmigaOS:test> mplayer -vo null -ao null -benchmark "sys:Tools/Media/Danny and 
Stephen Fellner/AmigaOS.mpg"
MPlayer 1.5 SVN-r38423-snapshot (C) 2000-2023 MPlayer Team

Playing sys:Tools/Media/Danny and Stephen Fellner/AmigaOS.mpg.
libavformat version 60.3.100 (internal)
MPEG-PS file format detected.
VIDEO:  MPEG2  640x320  (aspect 1)  25.000 fps    0.0 kbps ( 0.0 kbyte/s)
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
libavcodec version 60.3.100 (internal)
Selected video codec: [ffmpeg2] vfm: ffmpeg (FFmpeg MPEG-2)
==========================================================================
Load subtitles in sys:Tools/Media/Danny and Stephen Fellner/
==========================================================================
Opening audio decoder: [mpg123] MPEG 1.0/2.0/2.5 layers I, II, III
AUDIO: 48000 Hz, 2 ch, s16be, 224.0 kbit/14.58% (ratio: 28000->192000)
Selected audio codec: [mpg123] afm: mpg123 (MPEG 1.0/2.0/2.5 layers I, II, III)
==========================================================================


BENCHMARKs: VC: 207.685s VO:   0.336s A:  14.192s Sys:   7.359s =  229.572s
BENCHMARK%: VC: 90.4662% VO:  0.1466% A:  6.1817% Sys:  3.2055% = 100.0000%

Exiting... (End of file)

> On Wed Oct 25, 2023 at 2:01 AM AEST, BALATON Zoltan wrote:
>> On Wed, 11 Oct 2023, Nicholas Piggin wrote:
>>> On Tue Oct 10, 2023 at 10:41 PM AEST, BALATON Zoltan wrote:
>>>> Hello,
>>>> 
>>>> I have a question about tlbwe emulation in TCG for PPC440. This seems to
>>>> be implemented in mmu_helper.c::helper_440_tlbwe which calls tlb_flush a
>>>> lot flushing all TLB entries. This causes a big performance hit with
>>>> sam460ex running AmigaOS which seems to do tlbwe on every task or context
>>>> switch so it runs much slower than on other machines with a G4 CPU
>>>> (pegasos2 and amigaone we also emulate) that use hardware TLB which does
>>>> not have such problem in TCG. Even the embedded TLB emulation has 3
>>>> versions for 40x, 440 and BookE 2.06 (I think that's e500) and at least
>>>> the booke206 version uses flush_page instead of flushing everything. I
>>>> don't know much about this so is there somebody with better understanding
>>>> of this who can have a look at it and see if it can be optimised to
>>>> resolve this problem or give some advice?
>>> 
>>> It looks like 440 might be able to use the same page flushing as 4xx.
>>> 
>>> This patch is only compile tested and I don't know the book E TLB stuff
>>> too well but it may give you a starting point.
>> 
>> A few more people gave this some testing and it seems to work and found no
>> breakage so far. Do you plan to make it a porper patch and merge it
>> sometimes?
> 
> Performance is improved do you think? I can give it a try. I may try to
> do the fix patches separately ahead of the performance patch. It would
> be nice if those could be confirmed to fix a problem, but understand
> it can be difficult to set up and hit TLB bugs.