我使用以下两个makefile来编译我的程序以进行高斯模糊:
有人能给出一些解释吗?
这是源代码:https://github.com/makeapp007/interpolateFloatImg 我会尽快提供更多细节。
i7上的程序将在8个线程上运行。我不知道这个程序在E5上会生成多少个线程。
g++ -Ofast -ffast-math -march=native -flto -fwhole-program -std=c++11 -fopenmp -o interpolateFloatImg interpolateFloatImg.cpp
g++ -O3 -std=c++11 -fopenmp -o interpolateFloatImg interpolateFloatImg.cpp
- i7 4710HQ 4核8线程
- E5 2650
有人能给出一些解释吗?
这是源代码:https://github.com/makeapp007/interpolateFloatImg 我会尽快提供更多细节。
i7上的程序将在8个线程上运行。我不知道这个程序在E5上会生成多少个线程。
==== 更新 ====
我是该项目原作者的队友,以下是结果。
Arch-Lenovo-Y50 ~/project/ca/3/12 (git)-[master] % perf stat -d ./interpolateFloatImg lobby.bin out.bin 255 20
Kernel kernelSize : 255
Standard deviation : 20
Kernel maximum: 0.000397887
Kernel minimum: 1.22439e-21
Reading width 20265 height 8533 = 172921245
Micro seconds: 211199093
Performance counter stats for './interpolateFloatImg lobby.bin out.bin 255 20':
1423026.281358 task-clock:u (msec) # 6.516 CPUs utilized
0 context-switches:u # 0.000 K/sec
0 cpu-migrations:u # 0.000 K/sec
2,604 page-faults:u # 0.002 K/sec
4,167,572,543,807 cycles:u # 2.929 GHz (46.79%)
6,713,517,640,459 instructions:u # 1.61 insn per cycle (59.29%)
725,873,982,404 branches:u # 510.092 M/sec (57.28%)
23,468,237,735 branch-misses:u # 3.23% of all branches (56.99%)
544,480,682,764 L1-dcache-loads:u # 382.622 M/sec (37.00%)
545,000,783,842 L1-dcache-load-misses:u # 100.10% of all L1-dcache hits (31.44%)
38,696,703,292 LLC-loads:u # 27.193 M/sec (26.68%)
1,204,703,652 LLC-load-misses:u # 3.11% of all LL-cache hits (35.70%)
218.384387536 seconds time elapsed
这些是工作站的结果:
workstation:~/mossCAP3/repos/liuyh1_liujzh/12$ perf stat -d ./interpolateFloatImg ../../../lobby.bin out.bin 255 20
Kernel kernelSize : 255
Standard deviation : 20
Kernel maximum: 0.000397887
Kernel minimum: 1.22439e-21
Reading width 20265 height 8533 = 172921245
Micro seconds: 133661220
Performance counter stats for './interpolateFloatImg ../../../lobby.bin out.bin 255 20':
2035379.528531 task-clock (msec) # 14.485 CPUs utilized
7,370 context-switches # 0.004 K/sec
273 cpu-migrations # 0.000 K/sec
3,123 page-faults # 0.002 K/sec
5,272,393,071,699 cycles # 2.590 GHz [49.99%]
0 stalled-cycles-frontend # 0.00% frontend cycles idle
0 stalled-cycles-backend # 0.00% backend cycles idle
7,425,570,600,025 instructions # 1.41 insns per cycle [62.50%]
370,199,835,630 branches # 181.882 M/sec [62.50%]
47,444,417,555 branch-misses # 12.82% of all branches [62.50%]
591,137,049,749 L1-dcache-loads # 290.431 M/sec [62.51%]
545,926,505,523 L1-dcache-load-misses # 92.35% of all L1-dcache hits [62.51%]
38,725,975,976 LLC-loads # 19.026 M/sec [50.00%]
1,093,840,555 LLC-load-misses # 2.82% of all LL-cache hits [49.99%]
140.520016141 seconds time elapsed
====更新==== E5的规格:
workstation:~$ cat /proc/cpuinfo | grep name | cut -f2 -d: | uniq -c
20 Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz
workstation:~$ dmesg | grep cache
[ 0.041489] Dentry cache hash table entries: 4194304 (order: 13, 33554432 bytes)
[ 0.047512] Inode-cache hash table entries: 2097152 (order: 12, 16777216 bytes)
[ 0.050088] Mount-cache hash table entries: 65536 (order: 7, 524288 bytes)
[ 0.050121] Mountpoint-cache hash table entries: 65536 (order: 7, 524288 bytes)
[ 0.558666] PCI: pci_cache_line_size set to 64 bytes
[ 0.918203] VFS: Dquot-cache hash table entries: 512 (order 0, 4096 bytes)
[ 0.948808] xhci_hcd 0000:00:14.0: cache line size of 32 is not supported
[ 1.076303] ehci-pci 0000:00:1a.0: cache line size of 32 is not supported
[ 1.089022] ehci-pci 0000:00:1d.0: cache line size of 32 is not supported
[ 1.549796] sd 4:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 1.552711] sd 5:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[ 1.552955] sd 6:0:0:0: [sdc] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
perf stat ./interpolateFloatImg
和perf stat -d ./interpolateFloatImg
并将结果发布吗?这些结果将包含实际的 CPU 频率(行中的“cycles ... GHz”)。您的 E5 型号是什么(Xeon E5 CPU 有不同的版本:v1、v2、v3、v4)?没有源代码和详细的热点分析结果以及无法在自己的机器上重现测试的能力,没有人可以回答您的问题(http://stackoverflow.com/help/mcve - 在您的问题中没有最小、完整和可验证的示例)。 - osgxperf stat
的4个输出(system1上的program1,system2上的program1,system1上的program2,system2上的program2)以及perf stat -d
的4个输出如何?您使用了omp parallel for,尝试限制线程数到相同的值(export OMP_NUM_THREADS=4
)和/或export OMP_PROC_BIND=true
了吗? - osgxperf stat
呢? - osgxperf record
/perf report
对程序进行性能分析,找出热点(请查看我的更新答案)。并尝试重写参考程序。 - osgx