From: cheloha <cheloha@openbsd.org>
Date: Tue, 10 Jan 2023 01:01:18 +0000 (+0000)
Subject: i386: identifycpu(): only calibrate_cyclecounter() on primary CPU
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=ae6209ab7d3a89efddabb67562af7d6f2b7eb38f;p=openbsd

i386: identifycpu(): only calibrate_cyclecounter() on primary CPU

On i386 during identifycpu(), we call calibrate_cyclecounter() for every
CPU in the system.  This is pointless: every new call clobbers the cpuspeed
measured during the prior call.  It is also extremely slow: every call to
calibrate_cyclecounter() takes about 1 second.

Instead, let's only call calibrate_cyclecounter() once, on the primary CPU.
Multiprocessor i386 machines will now boot much faster.

ok deraadt@
---

diff --git a/sys/arch/i386/i386/machdep.c b/sys/arch/i386/i386/machdep.c
index bbf214750f1..708893b00fc 100644
--- a/sys/arch/i386/i386/machdep.c
+++ b/sys/arch/i386/i386/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.659 2023/01/10 00:49:45 cheloha Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.660 2023/01/10 01:01:18 cheloha Exp $	*/
 /*	$NetBSD: machdep.c,v 1.214 1996/11/10 03:16:17 thorpej Exp $	*/
 
 /*-
@@ -1861,7 +1861,8 @@ identifycpu(struct cpu_info *ci)
 			}
 			break;
 		}
-		calibrate_cyclecounter();
+		if (CPU_IS_PRIMARY(ci))
+			calibrate_cyclecounter();	/* set cpuspeed */
 	}
 
 	if (cpuid_level != -1)