Introduce a sysctl for reporting the number of fully populated reservations.

1 files changed, 32 insertions, 0 deletions

diff --git a/sys/vm/vm_reserv.c b/sys/vm/vm_reserv.c
index 2cfc630..34e69e1 100644
--- a/sys/vm/vm_reserv.c
+++ b/sys/vm/vm_reserv.c
@@ -217,6 +217,11 @@ static long vm_reserv_freed;
 SYSCTL_LONG(_vm_reserv, OID_AUTO, freed, CTLFLAG_RD,
     &vm_reserv_freed, 0, "Cumulative number of freed reservations");
 
+static int sysctl_vm_reserv_fullpop(SYSCTL_HANDLER_ARGS);
+
+SYSCTL_PROC(_vm_reserv, OID_AUTO, fullpop, CTLTYPE_INT | CTLFLAG_RD, NULL, 0,
+    sysctl_vm_reserv_fullpop, "I", "Current number of full reservations");
+
 static int sysctl_vm_reserv_partpopq(SYSCTL_HANDLER_ARGS);
 
 SYSCTL_OID(_vm_reserv, OID_AUTO, partpopq, CTLTYPE_STRING | CTLFLAG_RD, NULL, 0,
@@ -235,6 +240,33 @@ static void		vm_reserv_populate(vm_reserv_t rv, int index);
 static void		vm_reserv_reclaim(vm_reserv_t rv);
 
 /*
+ * Returns the current number of full reservations.
+ *
+ * Since the number of full reservations is computed without acquiring the
+ * free page queue lock, the returned value may be inexact.
+ */
+static int
+sysctl_vm_reserv_fullpop(SYSCTL_HANDLER_ARGS)
+{
+	vm_paddr_t paddr;
+	struct vm_phys_seg *seg;
+	vm_reserv_t rv;
+	int fullpop, segind;
+
+	fullpop = 0;
+	for (segind = 0; segind < vm_phys_nsegs; segind++) {
+		seg = &vm_phys_segs[segind];
+		paddr = roundup2(seg->start, VM_LEVEL_0_SIZE);
+		while (paddr + VM_LEVEL_0_SIZE <= seg->end) {
+			rv = &vm_reserv_array[paddr >> VM_LEVEL_0_SHIFT];
+			fullpop += rv->popcnt == VM_LEVEL_0_NPAGES;
+			paddr += VM_LEVEL_0_SIZE;
+		}
+	}
+	return (sysctl_handle_int(oidp, &fullpop, 0, req));
+}
+
+/*
  * Describes the current state of the partially-populated reservation queue.
  */
 static int