Feature request: temporary pinning (with do block) ?

[ederag]

pinthreads is able to stabilize benchmark runs inside Pluto too, thanks ! It seems to play well with the new Pluto/Malt combination.

Yet it would be nice to encapsulate a block (e.g. a benchmark) inside pinthreads, leaving the rest of the notebook running normally.

For instance, defining

# `with_pinthreads` instead of just `pinthreads` to avoid piracy
function with_pinthreads(f::Function, args...; kwargs...)
    pinthreads(args...; kwargs...)
    result = f()
    unpinthreads()
    result
end

allows

with_pinthreads([0]) do
    @benchmark sin.(x) setup=(x = rand(10))
end

Would that be in the ThreadPinning package scope ? Of course it would be better to store/restore the previous thread pinning (unpinned, :core, ...) instead of just unpinthreads(), but I fail to see how to do that.

[carstenbauer]

I think that such a feature would be a nice addition.

Of course it would be better to store/restore the previous thread pinning (unpinned, :core, ...) instead of just unpinthreads(), but I fail to see how to do that.

That's doable. We can simply query and store the affinity mask of each thread at the beginning and then to restore it at the end. (see ThreadPinning.get_affinity_mask / ThreadPinning.uv_thread_getaffinity)

[carstenbauer]

@ederag, added in https://github.com/carstenbauer/ThreadPinning.jl/pull/82. Please try it out!

[ederag]

82 works perfectly, tested with Pluto v0.19.32,

tried in particular

unpinthreads()  # outer setup unpinned
with_pinthreads([10]) do
    # runs on the 11th CPU, as expected
    @benchmark sin.(x) setup=(x = rand(10))
end
# runs on a random CPU (tested several times), as expected
@benchmark sin.(x) setup=(x = rand(10))

pinthreads([0])  # outer setup pinned to the first CPU
with_pinthreads([10]) do
    # runs on the 11th CPU, as expected
    @benchmark sin.(x) setup=(x = rand(10))
end
# runs on the first CPU, as expected
@benchmark sin.(x) setup=(x = rand(10))

Thanks !

[carstenbauer]

Great, I'll tag a new release.

[carstenbauer]

BTW, @ederag, if you care about ThreadPinning.jl in Pluto, I always wanted to have nicer support for threadinfo in Pluto. I'm thinking of

• native output (not in the terminal look)
• interactively updating (when one changes the pinning with pinthreads)

Maybe you want to give that a try? :)

[ederag]

Sorry, I'd like to help but I'm not good enough at HTML display stuff.

And I do not see how to get Pluto reactive updates for mutations (see https://github.com/fonsp/Pluto.jl/issues/564). Actually the operating system might be allowed to move threads (if unpinned), so a periodic polling seems adequate ? Here is a Pluto notebook (start the clock to get periodic updates).

Pluto people on zulip or discourse do amazing things and would probably be more helpful.