diff --git a/sys/alpha/alpha/pmap.c b/sys/alpha/alpha/pmap.c
index 59017cf6b91..c1d9ffa24ef 100644
--- a/sys/alpha/alpha/pmap.c
+++ b/sys/alpha/alpha/pmap.c
@@ -1367,6 +1367,8 @@ pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t mpte, vm_page_t m)
 	pv_entry_t pv;
 
 	pv = get_pv_entry();
+	if (pv == NULL)
+		panic("no pv entries: increase vm.pmap.shpgperproc");
 	pv->pv_va = va;
 	pv->pv_pmap = pmap;
 	pv->pv_ptem = mpte;
diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
index 4c188aaded2..029963a8966 100644
--- a/sys/amd64/amd64/pmap.c
+++ b/sys/amd64/amd64/pmap.c
@@ -1508,6 +1508,8 @@ pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t m)
 	pv_entry_t pv;
 
 	pv = get_pv_entry();
+	if (pv == NULL)
+		panic("no pv entries: increase vm.pmap.shpgperproc");
 	pv->pv_va = va;
 	pv->pv_pmap = pmap;
 
diff --git a/sys/i386/i386/pmap.c b/sys/i386/i386/pmap.c
index f712f83bda9..d813e168368 100644
--- a/sys/i386/i386/pmap.c
+++ b/sys/i386/i386/pmap.c
@@ -1510,6 +1510,8 @@ pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t m)
 	pv_entry_t pv;
 
 	pv = get_pv_entry();
+	if (pv == NULL)
+		panic("no pv entries: increase vm.pmap.shpgperproc");
 	pv->pv_va = va;
 	pv->pv_pmap = pmap;
 
diff --git a/sys/ia64/ia64/pmap.c b/sys/ia64/ia64/pmap.c
index 284801ff5d0..10f22ba483f 100644
--- a/sys/ia64/ia64/pmap.c
+++ b/sys/ia64/ia64/pmap.c
@@ -968,6 +968,8 @@ pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t m)
 	pv_entry_t pv;
 
 	pv = get_pv_entry();
+	if (pv == NULL)
+		panic("no pv entries: increase vm.pmap.shpgperproc");
 	pv->pv_pmap = pmap;
 	pv->pv_va = va;