Subject: CVS commit: [netbsd-2] src/sys/arch/i386/i386
To: None <>
From: Jeff Rizzo <>
List: source-changes
Date: 08/07/2005 15:34:10
Module Name:	src
Committed By:	riz
Date:		Sun Aug  7 15:34:10 UTC 2005

Modified Files:
	src/sys/arch/i386/i386 [netbsd-2]: identcpu.c

Log Message:
Pull up revision 1.21 (requested by reed in ticket #5551):
disable the use of TSC on Cyrix CPUs and document why:
When powersave mode is enabled, the TSC stops counting while the CPU is halted
in idle() waiting for an interrupt. This means we can't use the TSC for
interval time in microtime(9), and thus it is disabled here.
It still makes a perfectly good cycle counter for program profiling, so long
as you remember you're counting cycles, and not time. Further, if you don't
mind not using powersave mode, the TSC works just fine, so this should really
be optional. XXX

To generate a diff of this commit:
cvs rdiff -r1. -r1. src/sys/arch/i386/i386/identcpu.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.