Author: alc
Date: Tue Aug 7 04:48:14 2012
New Revision: 239121
URL: http://svn.freebsd.org/changeset/base/239121
Log:
Never sleep on busy pages in vm_pageout_launder(), always skip them. Long
ago, sleeping on busy pages in vm_pageout_launder() made sense. The call
to vm_pageout_flush() specified asynchronous I/O and sleeping on busy pages
blocked vm_pageout_launder() until the flush had completed. However, in
CVS revision 1.35 of vm/vm_contig.c, the call to vm_pageout_flush() was
changed to request synchronous I/O, but the sleep on busy pages was not
removed.
Modified:
head/sys/vm/vm_pageout.c
Modified: head/sys/vm/vm_pageout.c
==============================================================================
--- head/sys/vm/vm_pageout.c Tue Aug 7 00:42:46 2012 (r239120)
+++ head/sys/vm/vm_pageout.c Tue Aug 7 04:48:14 2012 (r239121)
@@ -586,23 +586,14 @@ vm_pageout_launder(int queue, int tries,
continue;
}
object = m->object;
- if (!VM_OBJECT_TRYLOCK(object) &&
+ if ((!VM_OBJECT_TRYLOCK(object) &&
(!vm_pageout_fallback_object_lock(m, &next) ||
- m->hold_count != 0)) {
+ m->hold_count != 0)) || (m->oflags & VPO_BUSY) != 0 ||
+ m->busy != 0) {
vm_page_unlock(m);
VM_OBJECT_UNLOCK(object);
continue;
}
- if ((m->oflags & VPO_BUSY) != 0 || m->busy != 0) {
- if (tries == 0) {
- vm_page_unlock(m);
- VM_OBJECT_UNLOCK(object);
- continue;
- }
- vm_page_sleep(m, "vpctw0");
- VM_OBJECT_UNLOCK(object);
- return (FALSE);
- }
vm_page_test_dirty(m);
if (m->dirty == 0)
pmap_remove_all(m);
_______________________________________________
[email protected] mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-head
To unsubscribe, send any mail to "[email protected]"
