From 4da9f125cc0a043b65b6fb8c7f29fb9d76d15925 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Tue, 30 Dec 2003 22:28:36 +0000 Subject: - Modify vm_object_split() to expect a locked vm object on entry and return on a locked vm object on exit. Remove GIANT_REQUIRED. - Eliminate some unnecessary local variables from vm_object_split(). --- sys/vm/vm_object.c | 25 ++++++++++--------------- 1 file changed, 10 insertions(+), 15 deletions(-) (limited to 'sys/vm/vm_object.c') diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c index 0099e52c0c95..43e337143868 100644 --- a/sys/vm/vm_object.c +++ b/sys/vm/vm_object.c @@ -1247,31 +1247,25 @@ vm_object_split(vm_map_entry_t entry) { vm_page_t m; vm_object_t orig_object, new_object, source; - vm_offset_t s, e; vm_pindex_t offidxstart, offidxend; vm_size_t idx, size; - vm_ooffset_t offset; - - GIANT_REQUIRED; orig_object = entry->object.vm_object; if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP) return; if (orig_object->ref_count <= 1) return; + VM_OBJECT_UNLOCK(orig_object); - offset = entry->offset; - s = entry->start; - e = entry->end; - - offidxstart = OFF_TO_IDX(offset); - offidxend = offidxstart + OFF_TO_IDX(e - s); + offidxstart = OFF_TO_IDX(entry->offset); + offidxend = offidxstart + OFF_TO_IDX(entry->end - entry->start); size = offidxend - offidxstart; - new_object = vm_pager_allocate(orig_object->type, - NULL, IDX_TO_OFF(size), VM_PROT_ALL, 0LL); - if (new_object == NULL) - return; + /* + * If swap_pager_copy() is later called, it will convert new_object + * into a swap object. + */ + new_object = vm_object_allocate(OBJT_DEFAULT, size); VM_OBJECT_LOCK(new_object); VM_OBJECT_LOCK(orig_object); @@ -1286,7 +1280,7 @@ vm_object_split(vm_map_entry_t entry) vm_object_clear_flag(source, OBJ_ONEMAPPING); VM_OBJECT_UNLOCK(source); new_object->backing_object_offset = - orig_object->backing_object_offset + offset; + orig_object->backing_object_offset + entry->offset; new_object->backing_object = source; } for (idx = 0; idx < size; idx++) { @@ -1334,6 +1328,7 @@ vm_object_split(vm_map_entry_t entry) entry->object.vm_object = new_object; entry->offset = 0LL; vm_object_deallocate(orig_object); + VM_OBJECT_LOCK(new_object); } #define OBSC_TEST_ALL_SHADOWED 0x0001 -- cgit v1.3