svn commit: r324972 - head/usr.bin/top

[Konstantin Belousov]

Author: kib
Date: Wed Oct 25 11:44:46 2017
New Revision: 324972
URL: https://svnweb.freebsd.org/changeset/base/324972

Log:
  Limit top display of total swap size by the max swap size system can
  handle.
  
  Keep both pagesize and the new swap_maxpages in the static variables
  to save sysctl calls.
  
  Submitted by:	ota at j.email.ne.jp
  PR:	223149
  MFC after:	2 weeks

Modified:
  head/usr.bin/top/machine.c

Modified: head/usr.bin/top/machine.c
==============================================================================
--- head/usr.bin/top/machine.c	Wed Oct 25 09:12:22 2017	(r324971)
+++ head/usr.bin/top/machine.c	Wed Oct 25 11:44:46 2017	(r324972)
@@ -1671,8 +1671,9 @@ static int
 swapmode(int *retavail, int *retfree)
 {
 	int n;
-	int pagesize = getpagesize();
 	struct kvm_swap swapary[1];
+	static int pagesize = 0;
+	static u_long swap_maxpages = 0;
 
 	*retavail = 0;
 	*retfree = 0;
@@ -1682,6 +1683,16 @@ swapmode(int *retavail, int *retfree)
 	n = kvm_getswapinfo(kd, swapary, 1, 0);
 	if (n < 0 || swapary[0].ksw_total == 0)
 		return (0);
+
+	if (pagesize == 0)
+		pagesize = getpagesize();
+	if (swap_maxpages == 0)
+		GETSYSCTL("vm.swap_maxpages", swap_maxpages);
+
+	/* ksw_total contains the total size of swap all devices which may
+	   exceed the maximum swap size allocatable in the system */
+	if ( swapary[0].ksw_total > swap_maxpages )
+		swapary[0].ksw_total = swap_maxpages;
 
 	*retavail = CONVERT(swapary[0].ksw_total);
 	*retfree = CONVERT(swapary[0].ksw_total - swapary[0].ksw_used);