svn commit: r236380 - head/sys/vm

[Eitan Adler]

Author: eadler
Date: Fri Jun  1 04:42:52 2012
New Revision: 236380
URL: http://svn.freebsd.org/changeset/base/236380

Log:
  Add sysctl to query amount of swap space free
  
  PR:		kern/166780
  Submitted by:	Radim Kolar <hsn at sendmail.cz>
  Approved by:	cperciva
  MFC after:	1 week

Modified:
  head/sys/vm/swap_pager.c

Modified: head/sys/vm/swap_pager.c
==============================================================================
--- head/sys/vm/swap_pager.c	Fri Jun  1 04:34:49 2012	(r236379)
+++ head/sys/vm/swap_pager.c	Fri Jun  1 04:42:52 2012	(r236380)
@@ -2692,3 +2692,18 @@ swaponvp(struct thread *td, struct vnode
 	    NODEV);
 	return (0);
 }
+
+static int
+sysctl_vm_swap_free(SYSCTL_HANDLER_ARGS) {
+	int swap_free, used;
+	int total;
+
+	swap_pager_status(&total, &used);
+
+	swap_free = (total - used) * PAGE_SIZE;
+	return SYSCTL_OUT(req, &swap_free, sizeof(swap_free));
+}
+
+SYSCTL_OID(_vm, OID_AUTO, swap_free, CTLTYPE_INT|CTLFLAG_RD|CTLFLAG_MPSAFE,
+		NULL, 0, sysctl_vm_swap_free, "Q",
+		"Blocks of free swap storage.");