o Relax locking assertions for vm_page_find_least()

o Relax locking assertions for pmap_enter_object() and add them also
  to architectures that currently don't have any
o Introduce VM_OBJECT_LOCK_DOWNGRADE() which is basically a downgrade
  operation on the per-object rwlock
o Use all the mechanisms above to make vm_map_pmap_enter() to work
  mostl of the times only with readlocks.

Sponsored by:	EMC / Isilon storage division
Reviewed by:	alc

3 files changed, 6 insertions, 0 deletions

diff --git a/sys/powerpc/aim/mmu_oea.c b/sys/powerpc/aim/mmu_oea.c
index 3c024de..17dcf66 100644
--- a/sys/powerpc/aim/mmu_oea.c
+++ b/sys/powerpc/aim/mmu_oea.c
@@ -1217,6 +1217,8 @@ moea_enter_object(mmu_t mmu, pmap_t pm, vm_offset_t start, vm_offset_t end,
 	vm_page_t m;
 	vm_pindex_t diff, psize;
 
+	VM_OBJECT_ASSERT_LOCKED(m_start->object);
+
 	psize = atop(end - start);
 	m = m_start;
 	rw_wlock(&pvh_global_lock);
diff --git a/sys/powerpc/aim/mmu_oea64.c b/sys/powerpc/aim/mmu_oea64.c
index 709501b..df91892 100644
--- a/sys/powerpc/aim/mmu_oea64.c
+++ b/sys/powerpc/aim/mmu_oea64.c
@@ -1360,6 +1360,8 @@ moea64_enter_object(mmu_t mmu, pmap_t pm, vm_offset_t start, vm_offset_t end,
 	vm_page_t m;
 	vm_pindex_t diff, psize;
 
+	VM_OBJECT_ASSERT_LOCKED(m_start->object);
+
 	psize = atop(end - start);
 	m = m_start;
 	while (m != NULL && (diff = m->pindex - m_start->pindex) < psize) {
diff --git a/sys/powerpc/booke/pmap.c b/sys/powerpc/booke/pmap.c
index a4de230..7e3c29e 100644
--- a/sys/powerpc/booke/pmap.c
+++ b/sys/powerpc/booke/pmap.c
@@ -1716,6 +1716,8 @@ mmu_booke_enter_object(mmu_t mmu, pmap_t pmap, vm_offset_t start,
 	vm_page_t m;
 	vm_pindex_t diff, psize;
 
+	VM_OBJECT_ASSERT_LOCKED(m_start->object);
+
 	psize = atop(end - start);
 	m = m_start;
 	rw_wlock(&pvh_global_lock);