@threads (incorrectly?) using :interactive thread pool

[robsmith11]

My intuition is that Threads.@threads should always be using the default thread pool, even when run from the REPL without Threads.@spawn, but if I run the following, I can see Julia only using a single thread, which I presume is from the interactive pool.

$ julia -t8,1
               _
   _       _ _(_)_     |  Documentation: https://docs.julialang.org
  (_)     | (_) (_)    |
   _ _   _| |_  __ _   |  Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 1.11.0-DEV.17 (2023-07-06)
 _/ |\__'_|_|_|\__'_|  |  Commit 2360140c9fd (0 days old master)
|__/                   |

julia> Threads.@threads for _ in 1:8
         while true
         end
       end

If I start julia with -t8, it uses all 8 cores because then there are no interactive threads, so I guess it decides to use the default pool instead. Starting julia with -t8,4 allows it to use 4 threads, so it clearly seems to be using interactive threads in that case.

If this is really the intended behavior, I think the docs should be more clear about that. But I think it would make more sense for it to always use the default pool.

[JeffBezanson]

I believe it is using the same pool as the current task, which is interactive for a REPL input. I do think it's good to use the current pool, but maybe that shouldn't extend to the interactive pool?