Openmp has no improvement?

[oym1994]

Hi, I compared the g2o graph pose optimization time cost with and without openmp. My hardware is : Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 12 On-line CPU(s) list: 0-11 Thread(s) per core: 2 Core(s) per socket: 6 Socket(s): 1 NUMA node(s): 1 Vendor ID: GenuineIntel CPU family: 6 Model: 166 Model name: Intel(R) Core(TM) i7-10710U CPU @ 1.10GHz Stepping: 0 CPU MHz: 3127.860 CPU max MHz: 4700.0000 CPU min MHz: 400.0000 BogoMIPS: 3199.92 Virtualization: VT-x L1d cache: 32K L1i cache: 32K L2 cache: 256K L3 cache: 12288K NUMA node0 CPU(s): 0-11 memory: 32G

the testing result is: About 70000 edges costs nearly 140s with 20 iterations About 74000edges costs nearly 160s with 20 iterations

It seems that openmp has no improvement!

Another problem is running without openmp performs much better than with openmp.

Have anyone also come across this problem?

Thanks!