From cd8266338a7951e4af840a9bf6a731ee07ccd65c Mon Sep 17 00:00:00 2001 From: alc Date: Tue, 7 Aug 2012 04:48:14 +0000 Subject: 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. --- sys/vm/vm_pageout.c | 15 +++------------ 1 file changed, 3 insertions(+), 12 deletions(-) (limited to 'sys/vm') diff --git a/sys/vm/vm_pageout.c b/sys/vm/vm_pageout.c index 3994ce1..6b1031f 100644 --- a/sys/vm/vm_pageout.c +++ b/sys/vm/vm_pageout.c @@ -586,23 +586,14 @@ vm_pageout_launder(int queue, int tries, vm_paddr_t low, vm_paddr_t high) 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); -- cgit v1.1