From: sf <sf@openbsd.org>
Date: Mon, 6 Jan 2014 14:29:25 +0000 (+0000)
Subject: Increase NPTECL, as cache-lines are 64-bytes nowadays.
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=b43c51177193464500421e4b1a0f2193c8d72493;p=openbsd

Increase NPTECL, as cache-lines are 64-bytes nowadays.
Also move it from pmap.h to pmap.c because it is an internal detail.
---

diff --git a/sys/arch/i386/i386/pmap.c b/sys/arch/i386/i386/pmap.c
index 1fc52617d3f..eaea6c1288a 100644
--- a/sys/arch/i386/i386/pmap.c
+++ b/sys/arch/i386/i386/pmap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pmap.c,v 1.158 2013/02/13 20:45:41 kurt Exp $	*/
+/*	$OpenBSD: pmap.c,v 1.159 2014/01/06 14:29:25 sf Exp $	*/
 /*	$NetBSD: pmap.c,v 1.91 2000/06/02 17:46:37 thorpej Exp $	*/
 
 /*
@@ -288,6 +288,12 @@ struct pmap_head pmaps;
 
 struct pool pmap_pmap_pool;
 
+/*
+ * Number of PTE's per cache line.  4 byte pte, 64-byte cache line
+ * Used to avoid false sharing of cache lines.
+ */
+#define NPTECL			16
+
 /*
  * MULTIPROCESSOR: special VA's/ PTE's are actually allocated inside a
  * MAXCPUS*NPTECL array of PTE's, to avoid cache line thrashing
@@ -858,7 +864,7 @@ pmap_bootstrap(vaddr_t kva_start)
 	/*
 	 * Waste some VA space to avoid false sharing of cache lines
 	 * for page table pages: Give each possible CPU a cache line
-	 * of PTE's (8) to play with, though we only need 4.  We could
+	 * of PTE's (16) to play with, though we only need 4.  We could
 	 * recycle some of this waste by putting the idle stacks here
 	 * as well; we could waste less space if we knew the largest
 	 * CPU ID beforehand.
diff --git a/sys/arch/i386/i386/pmapae.c b/sys/arch/i386/i386/pmapae.c
index f8b792437fb..2617fd17eb2 100644
--- a/sys/arch/i386/i386/pmapae.c
+++ b/sys/arch/i386/i386/pmapae.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pmapae.c,v 1.22 2013/02/09 20:37:41 miod Exp $	*/
+/*	$OpenBSD: pmapae.c,v 1.23 2014/01/06 14:29:25 sf Exp $	*/
 
 /*
  * Copyright (c) 2006 Michael Shalayeff
@@ -516,10 +516,10 @@ typedef u_int64_t pd_entry_t;	/* PDE */
 typedef u_int64_t pt_entry_t;	/* PTE */
 
 /*
- * Number of PTE's per cache line. 8 byte pte, 32-byte cache line
+ * Number of PTE's per cache line. 8 byte pte, 64-byte cache line
  * Used to avoid false sharing of cache lines.
  */
-#define	NPTECL		4
+#define	NPTECL		8
 
 /*
  * other data structures
diff --git a/sys/arch/i386/include/pmap.h b/sys/arch/i386/include/pmap.h
index ff132c6ad65..33bad6e20fc 100644
--- a/sys/arch/i386/include/pmap.h
+++ b/sys/arch/i386/include/pmap.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pmap.h,v 1.62 2013/03/31 17:07:03 deraadt Exp $	*/
+/*	$OpenBSD: pmap.h,v 1.63 2014/01/06 14:29:25 sf Exp $	*/
 /*	$NetBSD: pmap.h,v 1.44 2000/04/24 17:18:18 thorpej Exp $	*/
 
 /*
@@ -230,12 +230,6 @@
 #define PG_PVLIST	PG_AVAIL2	/* mapping has entry on pvlist */
 #define	PG_X		PG_AVAIL3	/* executable mapping */
 
-/*
- * Number of PTE's per cache line.  4 byte pte, 32-byte cache line
- * Used to avoid false sharing of cache lines.
- */
-#define NPTECL			8
-
 #ifdef _KERNEL
 /*
  * pmap data structures: see pmap.c for details of locking.