--- a/src/Pure/Tools/build_schedule.scala Fri Nov 24 10:34:10 2023 +0100
+++ b/src/Pure/Tools/build_schedule.scala Fri Nov 24 10:36:23 2023 +0100
@@ -84,7 +84,8 @@
val is_mono = entries == mono_prefix
val in_prefix = mono_prefix.length > 1 && threads <= mono_prefix.last._1
- val in_inflection = !is_mono && threads < entries.drop(mono_prefix.length).head._1
+ val in_inflection =
+ !is_mono && mono_prefix.length > 1 && threads < entries.drop(mono_prefix.length).head._1
if (is_mono || in_prefix || in_inflection) {
// Model with Amdahl's law
val t_p =