From a99a514c87def1f63bc7f3d5677c6248f38c9118 Mon Sep 17 00:00:00 2001 From: jhb Date: Wed, 24 Oct 2001 22:15:38 +0000 Subject: [PATCH] Document the requirements and nature of the logical CPU IDs. It isn't very strict and leaves much up to the platform so that it can define a convenient mapping. Requested by: mjacob --- sys/kern/subr_pcpu.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/sys/kern/subr_pcpu.c b/sys/kern/subr_pcpu.c index 47ac12e12edf..10a0d988ea42 100644 --- a/sys/kern/subr_pcpu.c +++ b/sys/kern/subr_pcpu.c @@ -32,6 +32,16 @@ /* * This module provides MI support for per-cpu data. + * + * Each architecture determines the mapping of logical CPU IDs to physical + * CPUs. The requirements of this mapping are as follows: + * - Logical CPU IDs must reside in the range 0 ... MAXCPU - 1. + * - The mapping is not required to be dense. That is, there may be + * gaps in the mappings. + * - The platform sets the value of MAXCPU in . + * - It is suggested, but not required, that in the non-SMP case, the + * platform define MAXCPU to be 1 and define the logical ID of the + * sole CPU as 0. */ #include