Switch the vm_object mutex to be a rwlock. This will enable in the

future further optimizations where the vm_object lock will be held
in read mode most of the time the page cache resident pool of pages
are accessed for reading purposes.

The change is mostly mechanical but few notes are reported:
* The KPI changes as follow:
  - VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK()
  - VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK()
  - VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK()
  - VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED()
    (in order to avoid visibility of implementation details)
  - The read-mode operations are added:
    VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(),
    VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED()
* The vm/vm_pager.h namespace pollution avoidance (forcing requiring
  sys/mutex.h in consumers directly to cater its inlining functions
  using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h
  consumers now must include also sys/rwlock.h.
* zfs requires a quite convoluted fix to include FreeBSD rwlocks into
  the compat layer because the name clash between FreeBSD and solaris
  versions must be avoided.
  At this purpose zfs redefines the vm_object locking functions
  directly, isolating the FreeBSD components in specific compat stubs.

The KPI results heavilly broken by this commit.  Thirdy part ports must
be updated accordingly (I can think off-hand of VirtualBox, for example).

Sponsored by:	EMC / Isilon storage division
Reviewed by:	jeff
Reviewed by:	pjd (ZFS specific review)
Discussed with:	alc
Tested by:	pho

11 files changed, 74 insertions, 65 deletions

diff --git a/sys/dev/agp/agp.c b/sys/dev/agp/agp.c
index 79b2d54bdad8..2c3e4b951457 100644
--- a/sys/dev/agp/agp.c
+++ b/sys/dev/agp/agp.c
@@ -41,6 +41,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/lock.h>
 #include <sys/mutex.h>
 #include <sys/proc.h>
+#include <sys/rwlock.h>
 
 #include <dev/agp/agppriv.h>
 #include <dev/agp/agpvar.h>
@@ -544,7 +545,7 @@ agp_generic_bind_memory(device_t dev, struct agp_memory *mem,
 	 * because vm_page_grab() may sleep and we can't hold a mutex
 	 * while sleeping.
 	 */
-	VM_OBJECT_LOCK(mem->am_obj);
+	VM_OBJECT_WLOCK(mem->am_obj);
 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
 		/*
 		 * Find a page from the object and wire it
@@ -557,14 +558,14 @@ agp_generic_bind_memory(device_t dev, struct agp_memory *mem,
 		    VM_ALLOC_WIRED | VM_ALLOC_ZERO | VM_ALLOC_RETRY);
 		AGP_DPF("found page pa=%#jx\n", (uintmax_t)VM_PAGE_TO_PHYS(m));
 	}
-	VM_OBJECT_UNLOCK(mem->am_obj);
+	VM_OBJECT_WUNLOCK(mem->am_obj);
 
 	mtx_lock(&sc->as_lock);
 
 	if (mem->am_is_bound) {
 		device_printf(dev, "memory already bound\n");
 		error = EINVAL;
-		VM_OBJECT_LOCK(mem->am_obj);
+		VM_OBJECT_WLOCK(mem->am_obj);
 		i = 0;
 		goto bad;
 	}
@@ -573,7 +574,7 @@ agp_generic_bind_memory(device_t dev, struct agp_memory *mem,
 	 * Bind the individual pages and flush the chipset's
 	 * TLB.
 	 */
-	VM_OBJECT_LOCK(mem->am_obj);
+	VM_OBJECT_WLOCK(mem->am_obj);
 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
 		m = vm_page_lookup(mem->am_obj, OFF_TO_IDX(i));
 
@@ -601,7 +602,7 @@ agp_generic_bind_memory(device_t dev, struct agp_memory *mem,
 		}
 		vm_page_wakeup(m);
 	}
-	VM_OBJECT_UNLOCK(mem->am_obj);
+	VM_OBJECT_WUNLOCK(mem->am_obj);
 
 	/*
 	 * Flush the cpu cache since we are providing a new mapping
@@ -622,7 +623,7 @@ agp_generic_bind_memory(device_t dev, struct agp_memory *mem,
 	return 0;
 bad:
 	mtx_unlock(&sc->as_lock);
-	VM_OBJECT_LOCK_ASSERT(mem->am_obj, MA_OWNED);
+	VM_OBJECT_ASSERT_WLOCKED(mem->am_obj);
 	for (k = 0; k < mem->am_size; k += PAGE_SIZE) {
 		m = vm_page_lookup(mem->am_obj, OFF_TO_IDX(k));
 		if (k >= i)
@@ -631,7 +632,7 @@ bad:
 		vm_page_unwire(m, 0);
 		vm_page_unlock(m);
 	}
-	VM_OBJECT_UNLOCK(mem->am_obj);
+	VM_OBJECT_WUNLOCK(mem->am_obj);
 
 	return error;
 }
@@ -658,14 +659,14 @@ agp_generic_unbind_memory(device_t dev, struct agp_memory *mem)
 	 */
 	for (i = 0; i < mem->am_size; i += AGP_PAGE_SIZE)
 		AGP_UNBIND_PAGE(dev, mem->am_offset + i);
-	VM_OBJECT_LOCK(mem->am_obj);
+	VM_OBJECT_WLOCK(mem->am_obj);
 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
 		m = vm_page_lookup(mem->am_obj, atop(i));
 		vm_page_lock(m);
 		vm_page_unwire(m, 0);
 		vm_page_unlock(m);
 	}
-	VM_OBJECT_UNLOCK(mem->am_obj);
+	VM_OBJECT_WUNLOCK(mem->am_obj);
 		
 	agp_flush_cache();
 	AGP_FLUSH_TLB(dev);
diff --git a/sys/dev/agp/agp_i810.c b/sys/dev/agp/agp_i810.c
index 9ec3992c61d8..63679e8c6e5b 100644
--- a/sys/dev/agp/agp_i810.c
+++ b/sys/dev/agp/agp_i810.c
@@ -56,6 +56,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/lock.h>
 #include <sys/mutex.h>
 #include <sys/proc.h>
+#include <sys/rwlock.h>
 
 #include <dev/agp/agppriv.h>
 #include <dev/agp/agpreg.h>
@@ -1967,10 +1968,10 @@ agp_i810_alloc_memory(device_t dev, int type, vm_size_t size)
 			 * Allocate and wire down the page now so that we can
 			 * get its physical address.
 			 */
-			VM_OBJECT_LOCK(mem->am_obj);
+			VM_OBJECT_WLOCK(mem->am_obj);
 			m = vm_page_grab(mem->am_obj, 0, VM_ALLOC_NOBUSY |
 			    VM_ALLOC_WIRED | VM_ALLOC_ZERO | VM_ALLOC_RETRY);
-			VM_OBJECT_UNLOCK(mem->am_obj);
+			VM_OBJECT_WUNLOCK(mem->am_obj);
 			mem->am_physical = VM_PAGE_TO_PHYS(m);
 		} else {
 			/* Our allocation is already nicely wired down for us.
@@ -2005,12 +2006,12 @@ agp_i810_free_memory(device_t dev, struct agp_memory *mem)
 			/*
 			 * Unwire the page which we wired in alloc_memory.
 			 */
-			VM_OBJECT_LOCK(mem->am_obj);
+			VM_OBJECT_WLOCK(mem->am_obj);
 			m = vm_page_lookup(mem->am_obj, 0);
 			vm_page_lock(m);
 			vm_page_unwire(m, 0);
 			vm_page_unlock(m);
-			VM_OBJECT_UNLOCK(mem->am_obj);
+			VM_OBJECT_WUNLOCK(mem->am_obj);
 		} else {
 			contigfree(sc->argb_cursor, mem->am_size, M_AGP);
 			sc->argb_cursor = NULL;
diff --git a/sys/dev/drm/drmP.h b/sys/dev/drm/drmP.h
index ffb69b47dfdd..bf5feedc7e6e 100644
--- a/sys/dev/drm/drmP.h
+++ b/sys/dev/drm/drmP.h
@@ -59,6 +59,7 @@ struct drm_file;
 #include <sys/fcntl.h>
 #include <sys/uio.h>
 #include <sys/filio.h>
+#include <sys/rwlock.h>
 #include <sys/sysctl.h>
 #include <sys/bus.h>
 #include <sys/queue.h>
diff --git a/sys/dev/drm2/drmP.h b/sys/dev/drm2/drmP.h
index 32c710a48928..8a456f1eb2c7 100644
--- a/sys/dev/drm2/drmP.h
+++ b/sys/dev/drm2/drmP.h
@@ -58,6 +58,7 @@ struct drm_file;
 #include <sys/fcntl.h>
 #include <sys/uio.h>
 #include <sys/filio.h>
+#include <sys/rwlock.h>
 #include <sys/selinfo.h>
 #include <sys/sysctl.h>
 #include <sys/bus.h>
diff --git a/sys/dev/drm2/i915/i915_gem.c b/sys/dev/drm2/i915/i915_gem.c
index 73c0b53f8099..f3f82e764737 100644
--- a/sys/dev/drm2/i915/i915_gem.c
+++ b/sys/dev/drm2/i915/i915_gem.c
@@ -990,14 +990,14 @@ i915_gem_swap_io(struct drm_device *dev, struct drm_i915_gem_object *obj,
 	vm_obj = obj->base.vm_obj;
 	ret = 0;
 
-	VM_OBJECT_LOCK(vm_obj);
+	VM_OBJECT_WLOCK(vm_obj);
 	vm_object_pip_add(vm_obj, 1);
 	while (size > 0) {
 		obj_pi = OFF_TO_IDX(offset);
 		obj_po = offset & PAGE_MASK;
 
 		m = i915_gem_wire_page(vm_obj, obj_pi);
-		VM_OBJECT_UNLOCK(vm_obj);
+		VM_OBJECT_WUNLOCK(vm_obj);
 
 		sched_pin();
 		sf = sf_buf_alloc(m, SFB_CPUPRIVATE);
@@ -1031,7 +1031,7 @@ i915_gem_swap_io(struct drm_device *dev, struct drm_i915_gem_object *obj,
 		}
 		sf_buf_free(sf);
 		sched_unpin();
-		VM_OBJECT_LOCK(vm_obj);
+		VM_OBJECT_WLOCK(vm_obj);
 		if (rw == UIO_WRITE)
 			vm_page_dirty(m);
 		vm_page_reference(m);
@@ -1044,7 +1044,7 @@ i915_gem_swap_io(struct drm_device *dev, struct drm_i915_gem_object *obj,
 			break;
 	}
 	vm_object_pip_wakeup(vm_obj);
-	VM_OBJECT_UNLOCK(vm_obj);
+	VM_OBJECT_WUNLOCK(vm_obj);
 
 	return (ret);
 }
@@ -1357,7 +1357,7 @@ i915_gem_pager_fault(vm_object_t vm_obj, vm_ooffset_t offset, int prot,
 	} else
 		oldm = NULL;
 retry:
-	VM_OBJECT_UNLOCK(vm_obj);
+	VM_OBJECT_WUNLOCK(vm_obj);
 unlocked_vmobj:
 	cause = ret = 0;
 	m = NULL;
@@ -1407,7 +1407,7 @@ unlocked_vmobj:
 		list_move_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
 
 	obj->fault_mappable = true;
-	VM_OBJECT_LOCK(vm_obj);
+	VM_OBJECT_WLOCK(vm_obj);
 	m = vm_phys_fictitious_to_vm_page(dev->agp->base + obj->gtt_offset +
 	    offset);
 	if (m == NULL) {
@@ -1452,7 +1452,7 @@ out:
 		kern_yield(PRI_USER);
 		goto unlocked_vmobj;
 	}
-	VM_OBJECT_LOCK(vm_obj);
+	VM_OBJECT_WLOCK(vm_obj);
 	vm_object_pip_wakeup(vm_obj);
 	return (VM_PAGER_ERROR);
 }
@@ -2208,12 +2208,12 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj,
 	obj->pages = malloc(page_count * sizeof(vm_page_t), DRM_I915_GEM,
 	    M_WAITOK);
 	vm_obj = obj->base.vm_obj;
-	VM_OBJECT_LOCK(vm_obj);
+	VM_OBJECT_WLOCK(vm_obj);
 	for (i = 0; i < page_count; i++) {
 		if ((obj->pages[i] = i915_gem_wire_page(vm_obj, i)) == NULL)
 			goto failed;
 	}
-	VM_OBJECT_UNLOCK(vm_obj);
+	VM_OBJECT_WUNLOCK(vm_obj);
 	if (i915_gem_object_needs_bit17_swizzle(obj))
 		i915_gem_object_do_bit_17_swizzle(obj);
 	return (0);
@@ -2226,7 +2226,7 @@ failed:
 		vm_page_unlock(m);
 		atomic_add_long(&i915_gem_wired_pages_cnt, -1);
 	}
-	VM_OBJECT_UNLOCK(vm_obj);
+	VM_OBJECT_WUNLOCK(vm_obj);
 	free(obj->pages, DRM_I915_GEM);
 	obj->pages = NULL;
 	return (-EIO);
@@ -2272,7 +2272,7 @@ i915_gem_object_put_pages_gtt(struct drm_i915_gem_object *obj)
 	if (obj->madv == I915_MADV_DONTNEED)
 		obj->dirty = 0;
 	page_count = obj->base.size / PAGE_SIZE;
-	VM_OBJECT_LOCK(obj->base.vm_obj);
+	VM_OBJECT_WLOCK(obj->base.vm_obj);
 #if GEM_PARANOID_CHECK_GTT
 	i915_gem_assert_pages_not_mapped(obj->base.dev, obj->pages, page_count);
 #endif
@@ -2287,7 +2287,7 @@ i915_gem_object_put_pages_gtt(struct drm_i915_gem_object *obj)
 		vm_page_unlock(m);
 		atomic_add_long(&i915_gem_wired_pages_cnt, -1);
 	}
-	VM_OBJECT_UNLOCK(obj->base.vm_obj);
+	VM_OBJECT_WUNLOCK(obj->base.vm_obj);
 	obj->dirty = 0;
 	free(obj->pages, DRM_I915_GEM);
 	obj->pages = NULL;
@@ -2309,7 +2309,7 @@ i915_gem_release_mmap(struct drm_i915_gem_object *obj)
 	if (devobj != NULL) {
 		page_count = OFF_TO_IDX(obj->base.size);
 
-		VM_OBJECT_LOCK(devobj);
+		VM_OBJECT_WLOCK(devobj);
 retry:
 		for (i = 0; i < page_count; i++) {
 			m = vm_page_lookup(devobj, i);
@@ -2319,7 +2319,7 @@ retry:
 				goto retry;
 			cdev_pager_free_page(devobj, m);
 		}
-		VM_OBJECT_UNLOCK(devobj);
+		VM_OBJECT_WUNLOCK(devobj);
 		vm_object_deallocate(devobj);
 	}
 
@@ -2437,9 +2437,9 @@ i915_gem_object_truncate(struct drm_i915_gem_object *obj)
 	vm_object_t vm_obj;
 
 	vm_obj = obj->base.vm_obj;
-	VM_OBJECT_LOCK(vm_obj);
+	VM_OBJECT_WLOCK(vm_obj);
 	vm_object_page_remove(vm_obj, 0, 0, false);
-	VM_OBJECT_UNLOCK(vm_obj);
+	VM_OBJECT_WUNLOCK(vm_obj);
 	obj->madv = I915_MADV_PURGED_INTERNAL;
 }
 
@@ -2488,7 +2488,7 @@ i915_gem_wire_page(vm_object_t object, vm_pindex_t pindex)
 	vm_page_t m;
 	int rv;
 
-	VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
+	VM_OBJECT_ASSERT_WLOCKED(object);
 	m = vm_page_grab(object, pindex, VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
 	if (m->valid != VM_PAGE_BITS_ALL) {
 		if (vm_pager_has_page(object, pindex, NULL, NULL)) {
@@ -3567,13 +3567,13 @@ i915_gem_detach_phys_object(struct drm_device *dev,
 	vaddr = obj->phys_obj->handle->vaddr;
 
 	page_count = obj->base.size / PAGE_SIZE;
-	VM_OBJECT_LOCK(obj->base.vm_obj);
+	VM_OBJECT_WLOCK(obj->base.vm_obj);
 	for (i = 0; i < page_count; i++) {
 		m = i915_gem_wire_page(obj->base.vm_obj, i);
 		if (m == NULL)
 			continue; /* XXX */
 
-		VM_OBJECT_UNLOCK(obj->base.vm_obj);
+		VM_OBJECT_WUNLOCK(obj->base.vm_obj);
 		sf = sf_buf_alloc(m, 0);
 		if (sf != NULL) {
 			dst = (char *)sf_buf_kva(sf);
@@ -3582,7 +3582,7 @@ i915_gem_detach_phys_object(struct drm_device *dev,
 		}
 		drm_clflush_pages(&m, 1);
 
-		VM_OBJECT_LOCK(obj->base.vm_obj);
+		VM_OBJECT_WLOCK(obj->base.vm_obj);
 		vm_page_reference(m);
 		vm_page_lock(m);
 		vm_page_dirty(m);
@@ -3590,7 +3590,7 @@ i915_gem_detach_phys_object(struct drm_device *dev,
 		vm_page_unlock(m);
 		atomic_add_long(&i915_gem_wired_pages_cnt, -1);
 	}
-	VM_OBJECT_UNLOCK(obj->base.vm_obj);
+	VM_OBJECT_WUNLOCK(obj->base.vm_obj);
 	intel_gtt_chipset_flush();
 
 	obj->phys_obj->cur_obj = NULL;
@@ -3632,7 +3632,7 @@ i915_gem_attach_phys_object(struct drm_device *dev,
 
 	page_count = obj->base.size / PAGE_SIZE;
 
-	VM_OBJECT_LOCK(obj->base.vm_obj);
+	VM_OBJECT_WLOCK(obj->base.vm_obj);
 	ret = 0;
 	for (i = 0; i < page_count; i++) {
 		m = i915_gem_wire_page(obj->base.vm_obj, i);
@@ -3640,14 +3640,14 @@ i915_gem_attach_phys_object(struct drm_device *dev,
 			ret = -EIO;
 			break;
 		}
-		VM_OBJECT_UNLOCK(obj->base.vm_obj);
+		VM_OBJECT_WUNLOCK(obj->base.vm_obj);
 		sf = sf_buf_alloc(m, 0);
 		src = (char *)sf_buf_kva(sf);
 		dst = (char *)obj->phys_obj->handle->vaddr + IDX_TO_OFF(i);
 		memcpy(dst, src, PAGE_SIZE);
 		sf_buf_free(sf);
 
-		VM_OBJECT_LOCK(obj->base.vm_obj);
+		VM_OBJECT_WLOCK(obj->base.vm_obj);
 
 		vm_page_reference(m);
 		vm_page_lock(m);
@@ -3655,7 +3655,7 @@ i915_gem_attach_phys_object(struct drm_device *dev,
 		vm_page_unlock(m);
 		atomic_add_long(&i915_gem_wired_pages_cnt, -1);
 	}
-	VM_OBJECT_UNLOCK(obj->base.vm_obj);
+	VM_OBJECT_WUNLOCK(obj->base.vm_obj);
 
 	return (0);
 }
diff --git a/sys/dev/drm2/ttm/ttm_bo_vm.c b/sys/dev/drm2/ttm/ttm_bo_vm.c
index 03e2f2b47129..3eb4cc7b31f9 100644
--- a/sys/dev/drm2/ttm/ttm_bo_vm.c
+++ b/sys/dev/drm2/ttm/ttm_bo_vm.c
@@ -118,7 +118,7 @@ ttm_bo_vm_fault(vm_object_t vm_obj, vm_ooffset_t offset,
 	} else
 		oldm = NULL;
 retry:
-	VM_OBJECT_UNLOCK(vm_obj);
+	VM_OBJECT_WUNLOCK(vm_obj);
 	m = NULL;
 
 reserve:
@@ -213,7 +213,7 @@ reserve:
 		    VM_MEMATTR_WRITE_BACK : ttm_io_prot(bo->mem.placement));
 	}
 
-	VM_OBJECT_LOCK(vm_obj);
+	VM_OBJECT_WLOCK(vm_obj);
 	if ((m->flags & VPO_BUSY) != 0) {
 		vm_page_sleep(m, "ttmpbs");
 		ttm_mem_io_unlock(man);
@@ -241,11 +241,11 @@ out_unlock1:
 	return (retval);
 
 out_io_unlock:
-	VM_OBJECT_LOCK(vm_obj);
+	VM_OBJECT_WLOCK(vm_obj);
 	goto out_io_unlock1;
 
 out_unlock:
-	VM_OBJECT_LOCK(vm_obj);
+	VM_OBJECT_WLOCK(vm_obj);
 	goto out_unlock1;
 }
 
diff --git a/sys/dev/drm2/ttm/ttm_tt.c b/sys/dev/drm2/ttm/ttm_tt.c
index 82547f17976c..35c22df947de 100644
--- a/sys/dev/drm2/ttm/ttm_tt.c
+++ b/sys/dev/drm2/ttm/ttm_tt.c
@@ -285,7 +285,7 @@ int ttm_tt_swapin(struct ttm_tt *ttm)
 
 	obj = ttm->swap_storage;
 
-	VM_OBJECT_LOCK(obj);
+	VM_OBJECT_WLOCK(obj);
 	vm_object_pip_add(obj, 1);
 	for (i = 0; i < ttm->num_pages; ++i) {
 		from_page = vm_page_grab(obj, i, VM_ALLOC_RETRY);
@@ -312,7 +312,7 @@ int ttm_tt_swapin(struct ttm_tt *ttm)
 		vm_page_wakeup(from_page);
 	}
 	vm_object_pip_wakeup(obj);
-	VM_OBJECT_UNLOCK(obj);
+	VM_OBJECT_WUNLOCK(obj);
 
 	if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTENT_SWAP))
 		vm_object_deallocate(obj);
@@ -322,7 +322,7 @@ int ttm_tt_swapin(struct ttm_tt *ttm)
 
 err_ret:
 	vm_object_pip_wakeup(obj);
-	VM_OBJECT_UNLOCK(obj);
+	VM_OBJECT_WUNLOCK(obj);
 	return (ret);
 }
 
@@ -346,7 +346,7 @@ int ttm_tt_swapout(struct ttm_tt *ttm, vm_object_t persistent_swap_storage)
 	} else
 		obj = persistent_swap_storage;
 
-	VM_OBJECT_LOCK(obj);
+	VM_OBJECT_WLOCK(obj);
 	vm_object_pip_add(obj, 1);
 	for (i = 0; i < ttm->num_pages; ++i) {
 		from_page = ttm->pages[i];
@@ -359,7 +359,7 @@ int ttm_tt_swapout(struct ttm_tt *ttm, vm_object_t persistent_swap_storage)
 		vm_page_wakeup(to_page);
 	}
 	vm_object_pip_wakeup(obj);
-	VM_OBJECT_UNLOCK(obj);
+	VM_OBJECT_WUNLOCK(obj);
 
 	ttm->bdev->driver->ttm_tt_unpopulate(ttm);
 	ttm->swap_storage = obj;
diff --git a/sys/dev/hwpmc/hwpmc_mod.c b/sys/dev/hwpmc/hwpmc_mod.c
index 2f2f05a76a3b..0c250bc411a2 100644
--- a/sys/dev/hwpmc/hwpmc_mod.c
+++ b/sys/dev/hwpmc/hwpmc_mod.c
@@ -50,6 +50,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/proc.h>
 #include <sys/queue.h>
 #include <sys/resourcevar.h>
+#include <sys/rwlock.h>
 #include <sys/sched.h>
 #include <sys/signalvar.h>
 #include <sys/smp.h>
@@ -1671,7 +1672,7 @@ pmc_log_process_mappings(struct pmc_owner *po, struct proc *p)
 		}
 
 		obj = entry->object.vm_object;
-		VM_OBJECT_LOCK(obj);
+		VM_OBJECT_WLOCK(obj);
 
 		/* 
 		 * Walk the backing_object list to find the base
@@ -1679,9 +1680,9 @@ pmc_log_process_mappings(struct pmc_owner *po, struct proc *p)
 		 */
 		for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
 			if (tobj != obj)
-				VM_OBJECT_LOCK(tobj);
+				VM_OBJECT_WLOCK(tobj);
 			if (lobj != obj)
-				VM_OBJECT_UNLOCK(lobj);
+				VM_OBJECT_WUNLOCK(lobj);
 			lobj = tobj;
 		}
 
@@ -1691,14 +1692,14 @@ pmc_log_process_mappings(struct pmc_owner *po, struct proc *p)
 		if (lobj == NULL) {
 			PMCDBG(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d "
 			    "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj);
-			VM_OBJECT_UNLOCK(obj);
+			VM_OBJECT_WUNLOCK(obj);
 			continue;
 		}
 
 		if (lobj->type != OBJT_VNODE || lobj->handle == NULL) {
 			if (lobj != obj)
-				VM_OBJECT_UNLOCK(lobj);
-			VM_OBJECT_UNLOCK(obj);
+				VM_OBJECT_WUNLOCK(lobj);
+			VM_OBJECT_WUNLOCK(obj);
 			continue;
 		}
 
@@ -1710,8 +1711,8 @@ pmc_log_process_mappings(struct pmc_owner *po, struct proc *p)
 		if (entry->start == last_end && lobj->handle == last_vp) {
 			last_end = entry->end;
 			if (lobj != obj)
-				VM_OBJECT_UNLOCK(lobj);
-			VM_OBJECT_UNLOCK(obj);
+				VM_OBJECT_WUNLOCK(lobj);
+			VM_OBJECT_WUNLOCK(obj);
 			continue;
 		}
 
@@ -1733,9 +1734,9 @@ pmc_log_process_mappings(struct pmc_owner *po, struct proc *p)
 		vp = lobj->handle;
 		vref(vp);
 		if (lobj != obj)
-			VM_OBJECT_UNLOCK(lobj);
+			VM_OBJECT_WUNLOCK(lobj);
 
-		VM_OBJECT_UNLOCK(obj);
+		VM_OBJECT_WUNLOCK(obj);
 
 		freepath = NULL;
 		pmc_getfilename(vp, &fullpath, &freepath);
diff --git a/sys/dev/md/md.c b/sys/dev/md/md.c
index b72f294912ab..18936b0be7e1 100644
--- a/sys/dev/md/md.c
+++ b/sys/dev/md/md.c
@@ -75,6 +75,7 @@
 #include <sys/namei.h>
 #include <sys/proc.h>
 #include <sys/queue.h>
+#include <sys/rwlock.h>
 #include <sys/sbuf.h>
 #include <sys/sched.h>
 #include <sys/sf_buf.h>
@@ -657,17 +658,17 @@ mdstart_swap(struct md_s *sc, struct bio *bp)
 	lastend = (bp->bio_offset + bp->bio_length - 1) % PAGE_SIZE + 1;
 
 	rv = VM_PAGER_OK;
-	VM_OBJECT_LOCK(sc->object);
+	VM_OBJECT_WLOCK(sc->object);
 	vm_object_pip_add(sc->object, 1);
 	for (i = bp->bio_offset / PAGE_SIZE; i <= lastp; i++) {
 		len = ((i == lastp) ? lastend : PAGE_SIZE) - offs;
 
 		m = vm_page_grab(sc->object, i,
 		    VM_ALLOC_NORMAL|VM_ALLOC_RETRY);
-		VM_OBJECT_UNLOCK(sc->object);
+		VM_OBJECT_WUNLOCK(sc->object);
 		sched_pin();
 		sf = sf_buf_alloc(m, SFB_CPUPRIVATE);
-		VM_OBJECT_LOCK(sc->object);
+		VM_OBJECT_WLOCK(sc->object);
 		if (bp->bio_cmd == BIO_READ) {
 			if (m->valid != VM_PAGE_BITS_ALL)
 				rv = vm_pager_get_pages(sc->object, &m, 1, 0);
@@ -732,7 +733,7 @@ mdstart_swap(struct md_s *sc, struct bio *bp)
 		offs = 0;
 	}
 	vm_object_pip_subtract(sc->object, 1);
-	VM_OBJECT_UNLOCK(sc->object);
+	VM_OBJECT_WUNLOCK(sc->object);
 	return (rv != VM_PAGER_ERROR ? 0 : ENOSPC);
 }
 
@@ -1068,7 +1069,7 @@ mdresize(struct md_s *sc, struct md_ioctl *mdio)
 		oldpages = OFF_TO_IDX(round_page(sc->mediasize));
 		newpages = OFF_TO_IDX(round_page(mdio->md_mediasize));
 		if (newpages < oldpages) {
-			VM_OBJECT_LOCK(sc->object);
+			VM_OBJECT_WLOCK(sc->object);
 			vm_object_page_remove(sc->object, newpages, 0, 0);
 			swap_pager_freespace(sc->object, newpages,
 			    oldpages - newpages);
@@ -1076,7 +1077,7 @@ mdresize(struct md_s *sc, struct md_ioctl *mdio)
 			    newpages), sc->cred);
 			sc->object->charge = IDX_TO_OFF(newpages);
 			sc->object->size = newpages;
-			VM_OBJECT_UNLOCK(sc->object);
+			VM_OBJECT_WUNLOCK(sc->object);
 		} else if (newpages > oldpages) {
 			res = swap_reserve_by_cred(IDX_TO_OFF(newpages -
 			    oldpages), sc->cred);
@@ -1093,10 +1094,10 @@ mdresize(struct md_s *sc, struct md_ioctl *mdio)
 					return (EDOM);
 				}
 			}
-			VM_OBJECT_LOCK(sc->object);
+			VM_OBJECT_WLOCK(sc->object);
 			sc->object->charge = IDX_TO_OFF(newpages);
 			sc->object->size = newpages;
-			VM_OBJECT_UNLOCK(sc->object);
+			VM_OBJECT_WUNLOCK(sc->object);
 		}
 		break;
 	default:
diff --git a/sys/dev/netmap/netmap.c b/sys/dev/netmap/netmap.c
index 35d530390b25..4fec31206dbc 100644
--- a/sys/dev/netmap/netmap.c
+++ b/sys/dev/netmap/netmap.c
@@ -81,6 +81,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/mman.h>	/* PROT_EXEC */
 #include <sys/poll.h>
 #include <sys/proc.h>
+#include <sys/rwlock.h>
 #include <vm/vm.h>	/* vtophys */
 #include <vm/pmap.h>	/* vtophys */
 #include <sys/socket.h> /* sockaddrs */
diff --git a/sys/dev/sound/pcm/dsp.c b/sys/dev/sound/pcm/dsp.c
index 2cfc1701d350..e52e46e00573 100644
--- a/sys/dev/sound/pcm/dsp.c
+++ b/sys/dev/sound/pcm/dsp.c
@@ -32,6 +32,8 @@
 
 #include <dev/sound/pcm/sound.h>
 #include <sys/ctype.h>
+#include <sys/lock.h>
+#include <sys/rwlock.h>
 #include <sys/sysent.h>
 
 #include <vm/vm.h>