An ambient occlusion renderer written in C. There is one workload which runs quickly and is single-threaded.
Topdown profile shows a fair retirement with backend stalls. Branch mispredictions are high while frontend stalls are low.
AMD metrics
elapsed 102.495
on_cpu 0.054 # 0.86 / 16 cores
utime 87.363
stime 1.020
nvcsw 1999 # 69.43%
nivcsw 880 # 30.57%
inblock 0 # 0.00/sec
onblock 86264 # 841.64/sec
cpu-clock 88410340018 # 88.410 seconds
task-clock 88413216623 # 88.413 seconds
page faults 304139 # 3439.972/sec
context switches 3221 # 36.431/sec
cpu migrations 283 # 3.201/sec
major page faults 2 # 0.023/sec
minor page faults 304137 # 3439.949/sec
alignment faults 0 # 0.000/sec
emulation faults 0 # 0.000/sec
branches 81795025595 # 92.951 branches per 1000 inst
branch misses 3180554743 # 3.89% branch miss
conditional 47929599290 # 54.467 conditional branches per 1000 inst
indirect 5305288022 # 6.029 indirect branches per 1000 inst
cpu-cycles 406522857441 # 0.25 GHz
instructions 877863716496 # 2.16 IPC
slots 815064673812 #
retiring 313009309772 # 38.4% (38.4%)
-- ucode 595913736 # 0.1%
-- fastpath 312413396036 # 38.3%
frontend 88237262487 # 10.8% (10.8%)
-- latency 48716465088 # 6.0%
-- bandwidth 39520797399 # 4.8%
backend 263992965803 # 32.4% (32.4%)
-- cpu 224705468131 # 27.6%
-- memory 39287497672 # 4.8%
speculation 149780891444 # 18.4% (18.4%) high
-- branch mispredict 148122841279 # 18.2%
-- pipeline restart 1658050165 # 0.2%
smt-contention 44009663 # 0.0% ( 0.0%)
cpu-cycles 406560579104 # 0.25 GHz
instructions 878913529305 # 2.16 IPC
instructions 293297866428 # 0.482 l2 access per 1000 inst
l2 hit from l1 121907588 # 18.04% l2 miss
l2 miss from l1 14912506 #
l2 hit from l2 pf 8978579 #
l3 hit from l2 pf 4321477 #
l3 miss from l2 pf 6292570 #
instructions 293187261114 # 286.414 float per 1000 inst
float 512 45 # 0.000 AVX-512 per 1000 inst
float 256 434 # 0.000 AVX-256 per 1000 inst
float 128 83972975802 # 286.414 AVX-128 per 1000 inst
float MMX 0 # 0.000 MMX per 1000 inst
float scalar 0 # 0.000 scalar per 1000 inst
instructions 2678177 #
opcache 992616 # 370.631 opcache per 1000 inst
opcache miss 535144 # 53.9% opcache miss rate
l1 dTLB miss 6691 # 2.498 L1 dTLB per 1000 inst
l2 dTLB miss 1192 # 0.445 L2 dTLB per 1000 inst
instructions 2716755 #
icache 1316655 # 484.643 icache per 1000 inst
icache miss 110449 # 8.4% icache miss rate
l1 iTLB miss 12 # 0.004 L1 iTLB per 1000 inst
l2 iTLB miss 0 # 0.000 L2 iTLB per 1000 inst
tlb flush 19 # 0.007 TLB flush per 1000 instIntel metrics show most of the memory time in L1 and hence also little backend memory stalls.
elapsed 99.367
on_cpu 0.053 # 0.85 / 16 cores
utime 83.595
stime 0.708
nvcsw 1838 # 77.85%
nivcsw 523 # 22.15%
inblock 376 # 3.78/sec
onblock 75024 # 755.02/sec
cpu-clock 84314176287 # 84.314 seconds
task-clock 84316871118 # 84.317 seconds
page faults 293264 # 3478.118/sec
context switches 2682 # 31.809/sec
cpu migrations 256 # 3.036/sec
major page faults 3 # 0.036/sec
minor page faults 293261 # 3478.082/sec
alignment faults 0 # 0.000/sec
emulation faults 0 # 0.000/sec
branches 81437652894 # 92.693 branches per 1000 inst
branch misses 3150488706 # 3.87% branch miss
conditional 81437664862 # 92.693 conditional branches per 1000 inst
indirect 5324683966 # 6.061 indirect branches per 1000 inst
slots 1909779189608 #
retiring 844514250146 # 44.2% (44.2%)
-- ucode 22927963393 # 1.2%
-- fastpath 821586286753 # 43.0%
frontend 97708395771 # 5.1% ( 5.1%)
-- latency 47599342664 # 2.5%
-- bandwidth 50109053107 # 2.6%
backend 424540183774 # 22.2% (22.2%)
-- cpu 384651028950 # 20.1%
-- memory 39889154824 # 2.1%
speculation 543044850727 # 28.4% (28.4%) high
-- branch mispredict 540435652666 # 28.3%
-- pipeline restart 2609198061 # 0.1%
smt-contention 0 # 0.0% ( 0.0%)
cpu-cycles 318526215737 # 0.20 GHz
instructions 878918735087 # 2.76 IPC
l2 access 306437238 # 0.349 l2 access per 1000 inst
l2 miss 95837357 # 31.27% l2 miss
cpu-cycles 318387579528 # 7.0% memory latency
load stalls 22063711216 # 6.7% l1 bound
l1 miss 799531261 # 0.1% l2 bound
l2 miss 402304447 # 0.0% l3 bound
l3 miss 286747182 # 0.1% dram bound
store_stalls 159923946 # 0.1% store bound
Process overview shows three invocations of “ao”
354 processes
3 ao 86.32 0.24
68 clinfo 15.86 6.66
38 vulkaninfo 0.96 1.15
6 glxinfo:gdrv0 0.12 0.06
6 glxinfo:gl0 0.12 0.06
4 vulkani:disk$0 0.10 0.12
6 php 0.06 0.08
2 glxinfo 0.06 0.03
2 glxinfo:cs0 0.06 0.03
2 glxinfo:disk$0 0.06 0.03
2 glxinfo:sh0 0.06 0.03
2 glxinfo:shlo0 0.06 0.03
6 clang 0.05 0.07
2 llvmpipe-0 0.05 0.06
2 llvmpipe-1 0.05 0.06
2 llvmpipe-10 0.05 0.06
2 llvmpipe-11 0.05 0.06
2 llvmpipe-12 0.05 0.06
2 llvmpipe-13 0.05 0.06
2 llvmpipe-14 0.05 0.06
2 llvmpipe-15 0.05 0.06
2 llvmpipe-2 0.05 0.06
2 llvmpipe-3 0.05 0.06
2 llvmpipe-4 0.05 0.06
2 llvmpipe-5 0.05 0.06
2 llvmpipe-6 0.05 0.06
2 llvmpipe-7 0.05 0.06
2 llvmpipe-8 0.05 0.06
2 llvmpipe-9 0.05 0.06
3 rocminfo 0.03 0.00
1 lspci 0.00 0.02
1 ps 0.00 0.01
82 sh 0.00 0.00
13 gcc 0.00 0.00
8 gsettings 0.00 0.00
8 stat 0.00 0.00
8 systemd-detect- 0.00 0.00
6 llvm-link 0.00 0.00
5 gmain 0.00 0.00
5 phoronix-test-s 0.00 0.00
3 aobench 0.00 0.00
3 dconf worker 0.00 0.00
2 cc 0.00 0.00
2 lscpu 0.00 0.00
2 uname 0.00 0.00
2 which 0.00 0.00
2 xset 0.00 0.00
1 date 0.00 0.00
1 dirname 0.00 0.00
1 dmesg 0.00 0.00
1 dmidecode 0.00 0.00
1 grep 0.00 0.00
1 ifconfig 0.00 0.00
1 ip 0.00 0.00
1 lsmod 0.00 0.00
1 mktemp 0.00 0.00
1 qdbus 0.00 0.00
1 readlink 0.00 0.00
1 realpath 0.00 0.00
1 sed 0.00 0.00
1 sort 0.00 0.00
1 stty 0.00 0.00
1 systemctl 0.00 0.00
1 template.sh 0.00 0.00
1 wc 0.00 0.00
1 xrandr 0.00 0.00
0 processes running
47 maximum processes
Computation blocks
356574) aobench cpu=6 start=5.50 finish=34.37
356575) ao cpu=8 start=5.51 finish=34.36
356578) aobench cpu=15 start=38.37 finish=67.28
356579) ao cpu=0 start=38.38 finish=67.27
356580) aobench cpu=14 start=71.28 finish=100.13
356581) ao cpu=7 start=71.28 finish=100.12