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- Modify vm_object_split() to expect a locked vm object on entry and

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return on a locked vm object on exit.  Remove GIANT_REQUIRED.
 - Eliminate some unnecessary local variables from vm_object_split().
This commit is contained in:
Alan Cox 2003-12-30 22:28:36 +00:00
parent 8a9ce5c0d2
commit 4da9f125cc
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=124008
2 changed files with 10 additions and 17 deletions
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2
sys/vm/vm_map.c
View file

@ -2306,10 +2306,8 @@ vm_map_copy_entry(
src_object->type == OBJT_SWAP)) {
vm_object_collapse(src_object);
if ((src_object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) {
VM_OBJECT_UNLOCK(src_object);
vm_object_split(src_entry);
src_object = src_entry->object.vm_object;
VM_OBJECT_LOCK(src_object);
}
}
vm_object_reference_locked(src_object);

25
sys/vm/vm_object.c
View file

@ -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