Multi-threaded С Binaries with TBB/OMP

[check4game]

Hello!

I read the document from the link #445, but I still don’t understand why OMP can’t be used.

I wrote a simple test based on example.c, which measures the time in 4 options for calculating blake3 for a file
https://github.com/check4game/MTBlake3

the result can be seen in the file https://github.com/check4game/MTBlake3/blob/main/i7-10700K.results.txt

it is important that the TBB2 and OMP2 results are the same

but, I found a problem with the implementation of tbb in the current version of blake3, on my computer the CPU load is 100%

CPU Usage: SGL,  1 Threads | 8%
CPU Usage: TBB, 16 Threads | 100%
CPU Usage: TBB,  2 Threads | 16%
CPU Usage: OMP,  2 Threads | 16%

thanks for your attention, I hope this is useful.

[check4game]

while everyone is reading and comprehending :)) I made a new version of the test program.

I think this version is more interesting.

https://github.com/check4game/MTBlake3/blob/main/i7-10700K.results.v.1.1.txt

v1.1, fileSize: 14461091840, sizeof(buf): 2097152, D:\temp\test3mix.1CD

CPU Usage: SGL,  1 Threads | 10%
CPU Usage: TBB, 16 Threads | 100%
CPU Usage: TBB,  2 Threads | 17%
CPU Usage: TBB,  4 Threads | 32%
CPU Usage: OMP,  2 Threads | 32%

thanks for your attention, I hope this is useful.

[check4game]

https://github.com/check4game/MTBlake3/blob/main/i7-10700K.results.v.1.2.txt

v1.2, fileSize: 14461091840, readSize: 2097152, D:\temp\test3mix.1CD
SGL,    1T, Time:  5.027 sec, CPU:   6.48%, Hash: df27698036f83e2bdbab0beff6b8351e562bdaceeec14f09554344f08b723f23
TBB,   16T, Time:  3.087 sec, CPU:  99.62%, Hash: df27698036f83e2bdbab0beff6b8351e562bdaceeec14f09554344f08b723f23
TBB,    2T, Time:  3.854 sec, CPU:  12.83%, Hash: df27698036f83e2bdbab0beff6b8351e562bdaceeec14f09554344f08b723f23
TBB,    4T, Time:  3.077 sec, CPU:  25.38%, Hash: df27698036f83e2bdbab0beff6b8351e562bdaceeec14f09554344f08b723f23
OMP, 2L|2T, Time:  3.064 sec, CPU:  25.19%, Hash: df27698036f83e2bdbab0beff6b8351e562bdaceeec14f09554344f08b723f23
OMP, 3L|2T, Time:  2.952 sec, CPU:  50.34%, Hash: df27698036f83e2bdbab0beff6b8351e562bdaceeec14f09554344f08b723f23