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

[Artyom Tarasenko]

Hi Dennis,


On Tue, Aug 25, 2015 at 7:45 AM, Dennis Luehring <address@hidden> wrote:
> 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

This is very surprising: the patch should have no effect on a sun4u machine.
Have you applied it to the master or some other branch?
Have you pulled the master branch recently? Maybe there was another
change affecting the performance?

Artyom

> 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
>



-- 
Regards,
Artyom Tarasenko

SPARC and PPC PReP under qemu blog: http://tyom.blogspot.com/search/label/qemu