CODEWITHSUNDEEP
linuxparallel-processingcputbb
Lily
Lily

Reputation: 846

Run TBB code on specific number of cpu

I'm running a tbb code on linux and I want to run my code using a portion of my CPU (2 out of 8). Is there another way except disabling cores.

Upvotes: 0

Views: 687

Answers (2)

Anton
Anton

Reputation: 6577

TBB respects the process affinity mask (on Linux: affinity mask of the [main] thread where TBB was initialized for the first time). So that by default, it will create worker threads in the quantity that takes into account the number of bits set to 1 in the affinity mask. For example, use taskset or numactl for setting the affinity mask. E.g.:

numactl --physcpubind=1,2 path/application arg1 arg2

It is like disabling the cores but for a specific process only.

You can also control the number of threads in the code using old tbb::task_scheduler_init or new tbb::global_control API. But it will not assign affinity mask to TBB threads, it just changes the number of threads.

If you want to manually assign affinity mask to the worker threads that TBB creates, derive you own class from tbb::task_scheduler_observer in order to define your custom actions for worker threads creation as described in this blog.

Upvotes: 1

Ignacio Vazquez-Abrams
Ignacio Vazquez-Abrams

Reputation: 799230

taskset(1) allows you to run a command on a specific subset of cores on the system.

taskset -c 0,1 ./a.out

Upvotes: 1

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