kernel: cpu: Add hint_spinwait()

This commit introduces a macro that must exist per
architecture (even if it does nothing) to ensure it is
machine independent.

Signed-off-by: Ian Moffett <ian@osmora.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/share/man/man9/arch.9 b/share/man/man9/arch.9
index 3285208..adbc437 100644
--- a/share/man/man9/arch.9
+++ b/share/man/man9/arch.9
@@ -95,6 +95,13 @@ The macro
 calls an internal function that fetches the
 cpu_info structure for the BSP.
 
+The macro
+.Ft hint_spinwait()
+hints the processor that it is currently
+in a spin-wait loop. This greatly reduces the
+processor’s power consumption and improves
+the performance of the spin-wait loop.
+
 The function these macros call must return a pointer
 to a
 .Ft cpu_info