Re: [Qemu-devel] [PATCH] target-sparc: Store mmu index in TB flags

[Dennis Luehring]

Am 25.08.2015 um 06:19 schrieb Richard Henderson:
> Artyom and Dennis, I'm hoping that this will help with some of your
> translation performance problems.  I don't currently have a sparc64
> kernel set up for booting, but I did smoke test this with openbios,
> and even there it reduced the number of TBs created.

i don't really can say it improves something - but maybe im just not the 
right person to interpret the numbers

your patch gives the worst result in stream benchmark but nearly the 
best in pugixml compile times and prime.c runtime
every tried patch or branch nearly halfs the speed of the stream 
benchmark comapred to qemu-git-master

legende:
tcg-indirect => git://github.com/rth7680/qemu.git  tcg-indirect
without-optimization => qemu-git-master + undefine USE_TCG_OPTIMIZATIONS
build flags for gcc are unrelevant because im using always the same

system:
Ubuntu 15.04 x64 Host, NetBSD SPARC64 guest running from ramdisk (to 
reduce io noise)

pugixml.cpp buildtime:
build: g++ src/pugixml.cpp -g -Wall -Wextra -Werror -pedantic -std=c++0x 
-c -MMD -MP

results:
tcg-indirect: ~2:46.5
qemu.org-git: ~2:51.2 !!WORST!!
without-optimization: ~2:14.1 !!BEST!!
patch-Store-mmu-index-in-TB-flags: 2:38.4

prime.c runtime (Aurelien Jarno sysbench extracted int primer)
build: gcc prime.c -o prime.out -lm)

results:
tcg-indirect: ~9.3 sec !!BEST!!
qemu-git-master: ~11 sec !!WORST!!
without-optimization: ~9.9 sec
patch-Store-mmu-index-in-TB-flags: ~9.7sec

stream (https://www.cs.virginia.edu/stream/)

build: gcc stream.c -o stream.out -lm)

tcg-indirect:
Function    Best Rate MB/s  Avg time     Min time     Max time
Copy:             320.8     0.511297     0.498785     0.590214
Scale:            187.0     0.858693     0.855465     0.863527
Add:              218.2     1.104654     1.099698     1.110341
Triad:            169.5     1.433273     1.416321     1.502248

qemu-git-master: !!BEST!!
Function    Best Rate MB/s  Avg time     Min time     Max time
Copy:             771.5     0.214717     0.207377     0.244214
Scale:            288.1     0.573320     0.555401     0.660161
Add:              423.5     0.633523     0.566661     1.092067
Triad:            242.9     1.053032     0.987970     1.499563

without-optimization:
Function    Best Rate MB/s  Avg time     Min time     Max time
Copy:             316.6     0.524065     0.505313     0.580103
Scale:            200.5     0.813356     0.798024     0.840986
Add:              243.9     1.010247     0.984025     1.119149
Triad:            182.9     1.345601     1.312236     1.427459

patch-Store-mmu-index-in-TB-flags: !!WORST!!
Function    Best Rate MB/s  Avg time     Min time     Max time
Copy:             276.2     0.585113     0.579193     0.595607
Scale:            181.3     0.895991     0.882744     0.917396
Add:              215.9     1.126226     1.111750     1.174236
Triad:            167.0     1.469888     1.436790     1.523211