Re: [PATCH v6 00/25] tcg-plugins: add hooks for discontinuities

["Julian Ganz" <neither@nut.email>]

September 7, 2025 at 10:21 PM, "BALATON Zoltan" wrote:
> I have uploaded some PPC binaries for the STREAM benchmark that I tested with before here:
> http://zero.eik.bme.hu/~balaton/qemu/stream-test.zip
> which may excercise this if run on sam460ex or ppce500 machines but I don't have a scripted test case for that. There is some docs on how to run Linux on these machines here:
> https://www.qemu.org/docs/master/system/target-ppc.html

After spending too much time looking for usable root-images (and then
giving up and just stuffing the executables in an ext2), I got to run
these beanchmarks on Linux 4.4.5 configured for the Sam460ex from [1].

I ran streamPPCpowerpcO3 on qemu with these patches:

-------------------------------------------------------------
Function    Best Rate MB/s  Avg time     Min time     Max time
Copy:            2867.6     0.056828     0.055795     0.061792
Scale:           1057.5     0.153282     0.151305     0.158115
Add:             1308.8     0.187095     0.183380     0.193672
Triad:           1111.6     0.220863     0.215902     0.230440
-------------------------------------------------------------

After doing a clean build, with the fans still audible:

-------------------------------------------------------------
Function    Best Rate MB/s  Avg time     Min time     Max time
Copy:            2932.9     0.055131     0.054554     0.055667
Scale:           1067.9     0.151520     0.149832     0.155000
Add:             1324.9     0.184807     0.181150     0.191386
Triad:           1122.0     0.220080     0.213896     0.229302
-------------------------------------------------------------

On qemu (6a9fa5ef3230a7d51e0d953a59ee9ef10af705b8) without these
patches, but plugins enabled:

-------------------------------------------------------------
Function    Best Rate MB/s  Avg time     Min time     Max time
Copy:            2972.1     0.054407     0.053834     0.054675
Scale:           1068.6     0.151503     0.149726     0.154594
Add:             1327.6     0.185160     0.180784     0.193181
Triad:           1127.2     0.219249     0.212915     0.229230
-------------------------------------------------------------

And on qemu (6a9fa5ef3230a7d51e0d953a59ee9ef10af705b8) without these
patches, with plugins disabled:

-------------------------------------------------------------
Function    Best Rate MB/s  Avg time     Min time     Max time
Copy:            2983.4     0.055141     0.053630     0.060013
Scale:           1058.3     0.152353     0.151186     0.155072
Add:             1323.9     0.184707     0.181279     0.188868
Triad:           1128.2     0.218674     0.212734     0.230314
-------------------------------------------------------------

I fail to see any significant indication that these patches, or
plugins in general, would result in a degredation of performance.

Regards,
Julian

[1]: http://www.supertuxkart-amiga.de/amiga/sam.html#downloads