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- Increase the scope of the vm object lock in vm_object_collapse().

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- Assert that the vm object and its backing vm object are both locked in
   vm_object_qcollapse().
This commit is contained in:
alc 2003-06-21 04:14:48 +00:00
parent 350708fbcc
commit ab509a1fdd
1 changed files with 4 additions and 3 deletions
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7
sys/vm/vm_object.c
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@ -1464,7 +1464,8 @@ vm_object_qcollapse(vm_object_t object)
{
vm_object_t backing_object = object->backing_object;
GIANT_REQUIRED;
VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
VM_OBJECT_LOCK_ASSERT(backing_object, MA_OWNED);
if (backing_object->ref_count != 1)
return;
@ -1524,7 +1525,6 @@ vm_object_collapse(vm_object_t object)
VM_OBJECT_UNLOCK(backing_object);
break;
}
/* XXX */ VM_OBJECT_UNLOCK(object);
/*
* We know that we can either collapse the backing object (if
* the parent is the only reference to it) or (perhaps) have
@ -1536,6 +1536,7 @@ vm_object_collapse(vm_object_t object)
* case.
*/
if (backing_object->ref_count == 1) {
/* XXX */ VM_OBJECT_UNLOCK(object);
/*
* If there is exactly one reference to the backing
* object, we can collapse it into the parent.
@ -1633,7 +1634,6 @@ vm_object_collapse(vm_object_t object)
*/
if (vm_object_backing_scan(object, OBSC_TEST_ALL_SHADOWED) == 0) {
VM_OBJECT_UNLOCK(backing_object);
/* XXX */ VM_OBJECT_LOCK(object);
break;
}
@ -1646,6 +1646,7 @@ vm_object_collapse(vm_object_t object)
backing_object->shadow_count--;
backing_object->generation++;
VM_OBJECT_UNLOCK(backing_object);
/* XXX */ VM_OBJECT_UNLOCK(object);
new_backing_object = backing_object->backing_object;
if ((object->backing_object = new_backing_object) != NULL) {