Following upon a KDL reported by atomozero, on wait-for-free-SMP-messages
on an unblock occurring with interrupts disabled.
In changing cpu_ent, move disabled to the beginning to avoid
enlarging the structure unncessarily.
On a 4-core VM, this skips around 200 sends during boot, and
over 3000 during a rebuild of HaikuDepot + mime_db (cold). On
bare metal (i3, 2x2), it skips around 150 during boot, and a bit
below 3000 during a rebuild of HaikuDepot + mime_db (over a much
longer time than in the VM, as the hardware is slower.)
Performance in the VM doesn't look much different. But this might
help in VirtualBox, or other situations where ICI latency is far
above what it should be.
Augustin Cavalier
19bcb3be0a