From fbddb38d93f7f55ac59ae27f0c7235ad0b91230b Mon Sep 17 00:00:00 2001
From: pjd <pjd@FreeBSD.org>
Date: Thu, 14 Dec 2006 14:32:59 +0000
Subject: [PATCH] Add support for _SC_PHYS_PAGES, which is not standard, but
 can be found in Solaris and Linux.

---
 lib/libc/gen/sysconf.3 | 13 +++++++++++++
 lib/libc/gen/sysconf.c | 15 ++++++++++++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/lib/libc/gen/sysconf.3 b/lib/libc/gen/sysconf.3
index 847651a3ca6e..85343c7122e8 100644
--- a/lib/libc/gen/sysconf.3
+++ b/lib/libc/gen/sysconf.3
@@ -167,6 +167,19 @@ otherwise \-1.
 Return 1 if the system supports the User Portability Utilities Option,
 otherwise \-1.
 .El
+.Pp
+These values also exist, but may not be standard:
+.Pp
+.Bl -tag -width 6n
+.Pp
+.It Li _SC_PHYS_PAGES
+The number of pages of physical memory.
+Note that it is possible that the product of this value and the value of
+.Li _SC_PAGESIZE
+will overflow a
+.Vt long
+in some configurations on a 32bit machine.
+.El
 .Sh RETURN VALUES
 If the call to
 .Fn sysconf
diff --git a/lib/libc/gen/sysconf.c b/lib/libc/gen/sysconf.c
index 27729a6fa9d4..fc844ccee902 100644
--- a/lib/libc/gen/sysconf.c
+++ b/lib/libc/gen/sysconf.c
@@ -79,9 +79,11 @@ sysconf(name)
 	int mib[2], sverrno, value;
 	long defaultresult;
 	const char *path;
+	const char *sname;
 
 	len = sizeof(value);
 	defaultresult = -1;
+	sname = NULL;
 
 	switch (name) {
 	case _SC_ARG_MAX:
@@ -574,9 +576,20 @@ yesno:		if (sysctl(mib, 2, &value, &len, NULL, 0) == -1)
 		mib[1] = HW_NCPU;
 		break;
 
+	case _SC_PHYS_PAGES:
+		sname = "hw.availpages";
+		break;
+
 	default:
 		errno = EINVAL;
 		return (-1);
 	}
-	return (sysctl(mib, 2, &value, &len, NULL, 0) == -1 ? -1 : value);
+	if (sname == NULL) {
+		if (sysctl(mib, 2, &value, &len, NULL, 0) == -1)
+			value = -1;
+	} else {
+		if (sysctlbyname(sname, &value, &len, NULL, 0) == -1)
+			value = -1;
+	}
+	return (value);
 }