From f081c0f8ad881d4efd90ff66583341dc688254b8 Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Mon, 10 Jul 2023 01:23:30 -0400
Subject: [PATCH] tweak: guess of chunk_size in `Fork_join`

---
 src/fork_join.ml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/fork_join.ml b/src/fork_join.ml
index 5b06ee79..9cc89251 100644
--- a/src/fork_join.ml
+++ b/src/fork_join.ml
@@ -100,7 +100,7 @@ let for_ ?chunk_size n (f : int -> int -> unit) : unit =
     | Some cs -> max 1 (min n cs)
     | None ->
       (* guess: try to have roughly one task per core *)
-      max 1 (n / Domain_.recommended_number ())
+      max 1 (1 + (n / D_pool_.n_domains ()))
   in
 
   let start_tasks ~run (suspension : Suspend_.suspension) =