Author: alc
Date: Wed Apr 28 04:57:32 2010
New Revision: 207306
URL: http://svn.freebsd.org/changeset/base/207306
Log:
Change vm_object_madvise() so that it checks whether the page is invalid
or unmanaged before acquiring the page queues lock. Neither of these
tests require that lock. Moreover, a better way of testing if the page
is unmanaged is to test the type of vm object. This avoids a pointless
vm_page_lookup().
MFC after: 3 weeks
Modified:
head/sys/vm/vm_object.c
Modified: head/sys/vm/vm_object.c
==============================================================================
--- head/sys/vm/vm_object.c Wed Apr 28 04:25:36 2010 (r207305)
+++ head/sys/vm/vm_object.c Wed Apr 28 04:57:32 2010 (r207306)
@@ -1162,7 +1162,8 @@ shadowlookup:
(tobject->flags & OBJ_ONEMAPPING) == 0) {
goto unlock_tobject;
}
- }
+ } else if (tobject->type == OBJT_PHYS)
+ goto unlock_tobject;
m = vm_page_lookup(tobject, tpindex);
if (m == NULL && advise == MADV_WILLNEED) {
/*
@@ -1189,18 +1190,13 @@ shadowlookup:
VM_OBJECT_UNLOCK(tobject);
tobject = backing_object;
goto shadowlookup;
- }
+ } else if (m->valid != VM_PAGE_BITS_ALL)
+ goto unlock_tobject;
/*
- * If the page is busy or not in a normal active state,
- * we skip it. If the page is not managed there are no
- * page queues to mess with. Things can break if we mess
- * with pages in any of the below states.
+ * If the page is not in a normal state, skip it.
*/
vm_page_lock_queues();
- if (m->hold_count ||
- m->wire_count ||
- (m->flags & PG_UNMANAGED) ||
- m->valid != VM_PAGE_BITS_ALL) {
+ if (m->hold_count != 0 || m->wire_count != 0) {
vm_page_unlock_queues();
goto unlock_tobject;
}
_______________________________________________
svn-src-head@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-head
To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
