@threads :Static seems not doing static scheduling?

General Usage
1

I start julia with set JULIA_EXCLUSIVE=1 and julia -t 2 and I have multi-threaded code. Meanwhile running it, I don’t know why I can not see two cores working with their maximum? but rather a switching between cores although I used static scheduling. This is actually is killing the performance for the parallel code. Any reason for that or to solve it?
Note that when I run the serial version of the code, somehow only two cores works (I don’t know also why not only one) but at least one core with its maximum

2

There’s no guarantee from the OS that one process thread will be pinned to one core, is there?

1 Like
3

It seems no guarantee, but then what is the meaning of using :Static with @threads?

4

static implies that tasks are pinned to threads, and won’t migrate between threads. This means that Threads.threadid() will be a constant throughout in the task. It does not mean that the thread can’t migrate between cores.

2 Likes
5

For pinning threads to cores (rather than tasks to threads), you should probably use [ANN] Announcing ThreadPinning.jl

1 Like
6

Based on the screenshots, I assume that the OP is on Windows, which currently isn’t supported by ThreadPinning.jl. Instead, @Amro, you can try setting the environment variable JULIA_EXCLUSIVE=1 before starting Julia.

1 Like
7

Thanks for your feedback. Yes, it is windows. I have already mentioned that I used it in powershell (do I need to use it in environment variable in windows?). But still no cores are pinned. Does it needs a special care?

8

Thanks for your feedback. As carstenbauer it is not supported for windows

9

Thanks for your feedback. Is there a package in windows to pin threads to cores in Julia?