svn commit: r217564 - head/sys/amd64/amd64

[Konstantin Belousov]

Author: kib
Date: Tue Jan 18 23:00:22 2011
New Revision: 217564
URL: http://svn.freebsd.org/changeset/base/217564

Log:
  Make the length of the LDT a loader tunable, machdep.max_ldt_segment,
  and export it with read-only sysctl. Remove unused defines.
  
  Reviewed by:	jhb (previous version)
  MFC after:	1 week

Modified:
  head/sys/amd64/amd64/sys_machdep.c

Modified: head/sys/amd64/amd64/sys_machdep.c
==============================================================================
--- head/sys/amd64/amd64/sys_machdep.c	Tue Jan 18 22:56:10 2011	(r217563)
+++ head/sys/amd64/amd64/sys_machdep.c	Tue Jan 18 23:00:22 2011	(r217564)
@@ -35,6 +35,7 @@ __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/systm.h>
+#include <sys/kernel.h>
 #include <sys/lock.h>
 #include <sys/malloc.h>
 #include <sys/mutex.h>
@@ -58,9 +59,24 @@ __FBSDID("$FreeBSD$");
 
 #include <security/audit/audit.h>
 
+#define	MAX_LD		8192
+
 int max_ldt_segment = 1024;
-#define LD_PER_PAGE 512
-#define	NULL_LDT_BASE	((caddr_t)NULL)
+SYSCTL_INT(_machdep, OID_AUTO, max_ldt_segment, CTLFLAG_RD, &max_ldt_segment,
+    0,
+    "Maximum number of allowed LDT segments in the single address space");
+
+static void
+max_ldt_segment_init(void *arg __unused)
+{
+
+	TUNABLE_INT_FETCH("machdep.max_ldt_segment", &max_ldt_segment);
+	if (max_ldt_segment <= 0)
+		max_ldt_segment = 1;
+	if (max_ldt_segment > MAX_LD)
+		max_ldt_segment = MAX_LD;
+}
+SYSINIT(maxldt, SI_SUB_VM_CONF, SI_ORDER_ANY, max_ldt_segment_init, NULL);
 
 #ifdef notyet
 #ifdef SMP