Two fixes to the out-of-swap process termination code. First, start killing

processes a little earlier to avoid a deadlock.  Second, when calculating
the 'largest process' do not just count RSS.  Instead count the RSS + SWAP
used by the process.  Without this the code tended to kill small
inconsequential processes like, oh, sshd, rather then one of the many
'eatmem 200MB' I run on a whim :-).  This fix has been extensively tested on
-stable and somewhat tested on -current and will be MFCd in a few days.

Shamed into fixing this by: ps

1 files changed, 35 insertions, 0 deletions

diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
index 428c194..d040819 100644
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -226,6 +226,41 @@ vmspace_free(vm)
 }
 
 /*
+ * vmspace_swap_count() - count the approximate swap useage in pages for a
+ *			  vmspace.
+ *
+ *	Swap useage is determined by taking the proportional swap used by
+ *	VM objects backing the VM map.  To make up for fractional losses,
+ *	if the VM object has any swap use at all the associated map entries
+ *	count for at least 1 swap page.
+ */
+int
+vmspace_swap_count(struct vmspace *vmspace)
+{
+    vm_map_t map = &vmspace->vm_map;
+    vm_map_entry_t cur;
+    int count = 0;
+
+    for (cur = map->header.next; cur != &map->header; cur = cur->next) {
+	vm_object_t object;
+
+	if ((cur->eflags & MAP_ENTRY_IS_SUB_MAP) == 0 &&
+	    (object = cur->object.vm_object) != NULL &&
+	    object->type == OBJT_SWAP
+	) {
+	    int n = (cur->end - cur->start) / PAGE_SIZE;
+
+	    if (object->un_pager.swp.swp_bcount) {
+		count += object->un_pager.swp.swp_bcount * SWAP_META_PAGES * n /
+			object->size + 1;
+	    }
+	}
+    }
+    return(count);
+}
+
+
+/*
  *	vm_map_create:
  *
  *	Creates and returns a new empty VM map with