From: Jeffrey Hsu <hsu@dragonflybsd.org>
Date: Fri, 5 Mar 2004 19:29:17 +0000 (+0000)
Subject: Remember the next lowest power of 2 of "npus" in "ncpus2".
X-Git-Tag: v2.0.1~11877
X-Git-Url: https://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/9010005588614e2173b1f5e8ce69a0185ff872a3

Remember the next lowest power of 2 of "npus" in "ncpus2".
---

diff --git a/sys/i386/i386/mp_machdep.c b/sys/i386/i386/mp_machdep.c
index 3677e42ba3..7df65b110e 100644
--- a/sys/i386/i386/mp_machdep.c
+++ b/sys/i386/i386/mp_machdep.c
@@ -23,7 +23,7 @@
  * SUCH DAMAGE.
  *
  * $FreeBSD: src/sys/i386/i386/mp_machdep.c,v 1.115.2.15 2003/03/14 21:22:35 jhb Exp $
- * $DragonFly: src/sys/i386/i386/Attic/mp_machdep.c,v 1.24 2004/03/01 06:33:16 dillon Exp $
+ * $DragonFly: src/sys/i386/i386/Attic/mp_machdep.c,v 1.25 2004/03/05 19:29:17 hsu Exp $
  */
 
 #include "opt_cpu.h"
@@ -1940,7 +1940,7 @@ default_mp_table(int type)
 static int
 start_all_aps(u_int boot_addr)
 {
-	int     x, i, pg;
+	int     x, i, pg, n;
 	u_char  mpbiosreason;
 	u_long  mpbioswarmvec;
 	struct mdglobaldata *gd;
@@ -2050,6 +2050,13 @@ start_all_aps(u_int boot_addr)
 	/* set ncpus to 1 + highest logical cpu.  Not all may have come up */
 	ncpus = x;
 
+	/* round ncpus down to power of 2 */
+	n = ncpus;
+	while (n >>= 1)
+		++ncpus2_shift;
+	ncpus2 = 1 << ncpus2_shift;
+	ncpus2_mask = ncpus2 - 1;
+
 	/* build our map of 'other' CPUs */
 	mycpu->gd_other_cpus = smp_startup_mask & ~(1 << mycpu->gd_cpuid);
 	mycpu->gd_ipiq = (void *)kmem_alloc(kernel_map, sizeof(lwkt_ipiq) * ncpus);
diff --git a/sys/kern/kern_synch.c b/sys/kern/kern_synch.c
index ee48b3def3..db1b370ca6 100644
--- a/sys/kern/kern_synch.c
+++ b/sys/kern/kern_synch.c
@@ -37,7 +37,7 @@
  *
  *	@(#)kern_synch.c	8.9 (Berkeley) 5/19/95
  * $FreeBSD: src/sys/kern/kern_synch.c,v 1.87.2.6 2002/10/13 07:29:53 kbyanc Exp $
- * $DragonFly: src/sys/kern/kern_synch.c,v 1.27 2004/01/30 05:42:17 dillon Exp $
+ * $DragonFly: src/sys/kern/kern_synch.c,v 1.28 2004/03/05 19:29:17 hsu Exp $
  */
 
 #include "opt_ktrace.h"
@@ -68,6 +68,7 @@ int	hogticks;
 int	lbolt;
 int	sched_quantum;		/* Roundrobin scheduling quantum in ticks. */
 int	ncpus;
+int	ncpus2, ncpus2_shift, ncpus2_mask;
 
 static struct callout loadav_callout;
 
diff --git a/sys/platform/pc32/i386/mp_machdep.c b/sys/platform/pc32/i386/mp_machdep.c
index cf2c49a1b7..c71de29711 100644
--- a/sys/platform/pc32/i386/mp_machdep.c
+++ b/sys/platform/pc32/i386/mp_machdep.c
@@ -23,7 +23,7 @@
  * SUCH DAMAGE.
  *
  * $FreeBSD: src/sys/i386/i386/mp_machdep.c,v 1.115.2.15 2003/03/14 21:22:35 jhb Exp $
- * $DragonFly: src/sys/platform/pc32/i386/mp_machdep.c,v 1.24 2004/03/01 06:33:16 dillon Exp $
+ * $DragonFly: src/sys/platform/pc32/i386/mp_machdep.c,v 1.25 2004/03/05 19:29:17 hsu Exp $
  */
 
 #include "opt_cpu.h"
@@ -1940,7 +1940,7 @@ default_mp_table(int type)
 static int
 start_all_aps(u_int boot_addr)
 {
-	int     x, i, pg;
+	int     x, i, pg, n;
 	u_char  mpbiosreason;
 	u_long  mpbioswarmvec;
 	struct mdglobaldata *gd;
@@ -2050,6 +2050,13 @@ start_all_aps(u_int boot_addr)
 	/* set ncpus to 1 + highest logical cpu.  Not all may have come up */
 	ncpus = x;
 
+	/* round ncpus down to power of 2 */
+	n = ncpus;
+	while (n >>= 1)
+		++ncpus2_shift;
+	ncpus2 = 1 << ncpus2_shift;
+	ncpus2_mask = ncpus2 - 1;
+
 	/* build our map of 'other' CPUs */
 	mycpu->gd_other_cpus = smp_startup_mask & ~(1 << mycpu->gd_cpuid);
 	mycpu->gd_ipiq = (void *)kmem_alloc(kernel_map, sizeof(lwkt_ipiq) * ncpus);
diff --git a/sys/sys/systm.h b/sys/sys/systm.h
index 7ed671ed01..9714ccd85f 100644
--- a/sys/sys/systm.h
+++ b/sys/sys/systm.h
@@ -37,7 +37,7 @@
  *
  *	@(#)systm.h	8.7 (Berkeley) 3/29/95
  * $FreeBSD: src/sys/sys/systm.h,v 1.111.2.18 2002/12/17 18:04:02 sam Exp $
- * $DragonFly: src/sys/sys/systm.h,v 1.17 2004/01/30 05:42:18 dillon Exp $
+ * $DragonFly: src/sys/sys/systm.h,v 1.18 2004/03/05 19:29:17 hsu Exp $
  */
 
 #ifndef _SYS_SYSTM_H_
@@ -84,6 +84,9 @@ extern int bootverbose;		/* nonzero to print verbose messages */
 extern int maxusers;		/* system tune hint */
 
 extern int ncpus;		/* total number of cpus (real, hyper, virtual)*/
+extern int ncpus2;		/* ncpus rounded down to power of 2 */
+extern int ncpus2_shift;	/* log base 2 of ncpus2 */
+extern int ncpus2_mask;		/* ncpus2 - 1 */
 
 #ifdef	INVARIANTS		/* The option is always available */
 #define	KASSERT(exp,msg)	do { if (!(exp)) panic msg; } while (0)