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Move the acquisition and release of the page queues lock outside of a loop

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in vm_object_split() to avoid repeated acquisition and release.
This commit is contained in:
Alan Cox 2005-01-08 23:41:11 +00:00
parent 76505d5adf
commit 5ba514bc89
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=139921
1 changed files with 3 additions and 2 deletions
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5
sys/vm/vm_object.c
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@ -1280,6 +1280,7 @@ vm_object_split(vm_map_entry_t entry)
orig_object->backing_object_offset + entry->offset;
new_object->backing_object = source;
}
vm_page_lock_queues();
for (idx = 0; idx < size; idx++) {
retry:
m = vm_page_lookup(orig_object, offidxstart + idx);
@ -1293,7 +1294,6 @@ vm_object_split(vm_map_entry_t entry)
* We do not have to VM_PROT_NONE the page as mappings should
* not be changed by this operation.
*/
vm_page_lock_queues();
if ((m->flags & PG_BUSY) || m->busy) {
vm_page_flag_set(m, PG_WANTED | PG_REFERENCED);
VM_OBJECT_UNLOCK(orig_object);
@ -1301,13 +1301,14 @@ vm_object_split(vm_map_entry_t entry)
msleep(m, &vm_page_queue_mtx, PDROP | PVM, "spltwt", 0);
VM_OBJECT_LOCK(new_object);
VM_OBJECT_LOCK(orig_object);
vm_page_lock_queues();
goto retry;
}
vm_page_rename(m, new_object, idx);
/* page automatically made dirty by rename and cache handled */
vm_page_busy(m);
vm_page_unlock_queues();
}
vm_page_unlock_queues();
if (orig_object->type == OBJT_SWAP) {
/*
* swap_pager_copy() can sleep, in which case the orig_object's