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Add vm object locking to vm_object_coalesce().

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This commit is contained in:
Alan Cox 2003-06-03 19:37:01 +00:00
parent 479728fd77
commit bdbfbaafcc
1 changed files with 12 additions and 7 deletions
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19
sys/vm/vm_object.c
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@ -1774,17 +1774,21 @@ vm_object_coalesce(vm_object_t prev_object, vm_pindex_t prev_pindex,
if (prev_object == NULL)
return (TRUE);
vm_object_lock(prev_object);
mtx_lock(&Giant);
VM_OBJECT_LOCK(prev_object);
if (prev_object->type != OBJT_DEFAULT &&
prev_object->type != OBJT_SWAP) {
vm_object_unlock(prev_object);
VM_OBJECT_UNLOCK(prev_object);
mtx_unlock(&Giant);
return (FALSE);
}
/*
* Try to collapse the object first
*/
VM_OBJECT_UNLOCK(prev_object);
vm_object_collapse(prev_object);
VM_OBJECT_LOCK(prev_object);
/*
* Can't coalesce if: . more than one reference . paged out . shadows
@ -1792,7 +1796,8 @@ vm_object_coalesce(vm_object_t prev_object, vm_pindex_t prev_pindex,
* pages not mapped to prev_entry may be in use anyway)
*/
if (prev_object->backing_object != NULL) {
vm_object_unlock(prev_object);
VM_OBJECT_UNLOCK(prev_object);
mtx_unlock(&Giant);
return (FALSE);
}
@ -1802,7 +1807,8 @@ vm_object_coalesce(vm_object_t prev_object, vm_pindex_t prev_pindex,
if ((prev_object->ref_count > 1) &&
(prev_object->size != next_pindex)) {
vm_object_unlock(prev_object);
VM_OBJECT_UNLOCK(prev_object);
mtx_unlock(&Giant);
return (FALSE);
}
@ -1811,14 +1817,12 @@ vm_object_coalesce(vm_object_t prev_object, vm_pindex_t prev_pindex,
* deallocation.
*/
if (next_pindex < prev_object->size) {
VM_OBJECT_LOCK(prev_object);
vm_object_page_remove(prev_object,
next_pindex,
next_pindex + next_size, FALSE);
if (prev_object->type == OBJT_SWAP)
swap_pager_freespace(prev_object,
next_pindex, next_size);
VM_OBJECT_UNLOCK(prev_object);
}
/*
@ -1827,7 +1831,8 @@ vm_object_coalesce(vm_object_t prev_object, vm_pindex_t prev_pindex,
if (next_pindex + next_size > prev_object->size)
prev_object->size = next_pindex + next_size;
vm_object_unlock(prev_object);
VM_OBJECT_UNLOCK(prev_object);
mtx_unlock(&Giant);
return (TRUE);
}