On 29-10-2022 12:01, Ludovic Courtès wrote:
> The attached Fibers program illustrates the problem: heap grows even
> though it’s not supposed to.

If I add (gc) before the (pk 'heap-size ...), I can't reproduce:

;;; (heap-size 12742656)

;;; (heap-size 12808192)

;;; (heap-size 12808192)

;;; (heap-size 12808192)

;;; (heap-size 12808192)

(another run)

;;; (heap-size 4976640)

;;; (heap-size 8855552)

;;; (heap-size 12029952)

;;; (heap-size 12029952)

;;; (heap-size 12029952)

However, if I increase the number of seconds waited, I can eventually 
reproduce some heap growth:

;;; (heap-size 12742656)

;;; (heap-size 12742656)

;;; (heap-size 12808192)

;;; (heap-size 12808192)

;;; (heap-size 12808192)

;;; (heap-size 12808192)

;;; (heap-size 12808192)

;;; (heap-size 12808192)

;;; (heap-size 12808192)

;;; (heap-size 12808192)

;;; (heap-size 12808192)
;; <--- here's the jump
;;; (heap-size 23359488)

;;; (heap-size 23359488)

;;; (heap-size 23359488)

;;; (heap-size 23359488)

;;; (heap-size 23359488)

;;; (heap-size 23359488)

;;; (heap-size 23359488)

;;; (heap-size 23359488)

;;; (heap-size 23359488)

(This is in a "guix shell guile guile-fibers" environment)

Greetings,
Maxime.