This commit is meant to solve a couple of VM system problems or

performance issues.

	1) The pmap module has had too many inlines, and so the
	   object file is simply bigger than it needs to be.
	   Some common code is also merged into subroutines.
	2) Removal of some *evil* PHYS_TO_VM_PAGE macro calls.
	   Unfortunately, a few have needed to be added also.
	   The removal caused the need for more vm_page_lookups.
	   I added lookup hints to minimize the need for the
	   page table lookup operations.
	3) Removal of some bogus performance improvements, that
	   mostly made the code more complex (tracking individual
	   page table page updates unnecessarily).  Those improvements
	   actually hurt 386 processors perf (not that people who
	   worry about perf use 386 processors anymore :-)).
	4) Changed pv queue manipulations/structures to be TAILQ's.
	5) The pv queue code has had some performance problems since
	   day one.  Some significant scalability issues are resolved
	   by threading the pv entries from the pmap AND the physical
	   address instead of just the physical address.  This makes
	   certain pmap operations run much faster.  This does
	   not affect most micro-benchmarks, but should help loaded system
	   performance *significantly*.  DG helped and came up with most
	   of the solution for this one.
	6) Most if not all pmap bit operations follow the pattern:
		pmap_test_bit();
		pmap_clear_bit();
	   That made for twice the necessary pv list traversal.   The
	   pmap interface now supports only pmap_tc_bit type operations:
	   pmap_[test/clear]_modified, pmap_[test/clear]_referenced.
	   Additionally, the modified routine now takes a vm_page_t arg
	   instead of a phys address.  This eliminates a PHYS_TO_VM_PAGE
	   operation.
	7) Several rewrites of routines that contain redundant code to
	   use common routines, so that there is a greater likelihood of
	   keeping the cache footprint smaller.

1 files changed, 28 insertions, 30 deletions

diff --git a/sys/vm/vm_pageout.c b/sys/vm/vm_pageout.c
index 98ad6ef..26df38c 100644
--- a/sys/vm/vm_pageout.c
+++ b/sys/vm/vm_pageout.c
@@ -314,12 +314,9 @@ do_backward:
 		}
 	}
 
-	/*
-	 * we allow reads during pageouts...
-	 */
 	for (i = page_base; i < (page_base + pageout_count); i++) {
 		mc[i]->flags |= PG_BUSY;
-		vm_page_protect(mc[i], VM_PROT_READ);
+		vm_page_protect(mc[i], VM_PROT_NONE);
 	}
 
 	return vm_pageout_flush(&mc[page_base], pageout_count, sync);
@@ -359,7 +356,7 @@ vm_pageout_flush(mc, count, sync)
 			 * essentially lose the changes by pretending it
 			 * worked.
 			 */
-			pmap_clear_modify(VM_PAGE_TO_PHYS(mt));
+			pmap_tc_modified(mt);
 			mt->dirty = 0;
 			break;
 		case VM_PAGER_ERROR:
@@ -446,7 +443,7 @@ vm_pageout_object_deactivate_pages(map, object, desired, map_remove_only)
 				continue;
 			}
 
-			refcount = pmap_ts_referenced(VM_PAGE_TO_PHYS(p));
+			refcount = pmap_tc_referenced(VM_PAGE_TO_PHYS(p));
 			if (refcount) {
 				p->flags |= PG_REFERENCED;
 			} else if (p->flags & PG_REFERENCED) {
@@ -586,7 +583,7 @@ vm_pageout_scan()
 
 	maxlaunder = (cnt.v_inactive_target > MAXLAUNDER) ?
 	    MAXLAUNDER : cnt.v_inactive_target;
-rescan0:
+
 	maxscan = cnt.v_inactive_count;
 	for( m = TAILQ_FIRST(&vm_page_queue_inactive);
 
@@ -599,7 +596,7 @@ rescan0:
 		cnt.v_pdpages++;
 
 		if (m->queue != PQ_INACTIVE) {
-			goto rescan0;
+			break;
 		}
 
 		next = TAILQ_NEXT(m, pageq);
@@ -621,32 +618,33 @@ rescan0:
 			continue;
 		}
 
-		if (m->object->ref_count == 0) {
-			m->flags &= ~PG_REFERENCED;
-			pmap_clear_reference(VM_PAGE_TO_PHYS(m));
-		} else if (((m->flags & PG_REFERENCED) == 0) &&
-			pmap_ts_referenced(VM_PAGE_TO_PHYS(m))) {
-			vm_page_activate(m);
-			continue;
-		}
-
-		if ((m->flags & PG_REFERENCED) != 0) {
-			m->flags &= ~PG_REFERENCED;
-			pmap_clear_reference(VM_PAGE_TO_PHYS(m));
-			vm_page_activate(m);
-			continue;
-		}
+		if (m->valid != 0) {
+			if (m->object->ref_count == 0) {
+				m->flags &= ~PG_REFERENCED;
+				pmap_tc_referenced(VM_PAGE_TO_PHYS(m));
+			} else if (((m->flags & PG_REFERENCED) == 0) &&
+				pmap_tc_referenced(VM_PAGE_TO_PHYS(m))) {
+				vm_page_activate(m);
+				continue;
+			}
 
-		if (m->dirty == 0) {
-			vm_page_test_dirty(m);
-		} else if (m->dirty != 0) {
-			m->dirty = VM_PAGE_BITS_ALL;
-		}
+			if ((m->flags & PG_REFERENCED) != 0) {
+				m->flags &= ~PG_REFERENCED;
+				pmap_tc_referenced(VM_PAGE_TO_PHYS(m));
+				vm_page_activate(m);
+				continue;
+			}
+			if (m->dirty == 0) {
+				vm_page_test_dirty(m);
+			} else if (m->dirty != 0) {
+				m->dirty = VM_PAGE_BITS_ALL;
+			}
+		} 
 
 		if (m->valid == 0) {
 			vm_page_protect(m, VM_PROT_NONE);
 			vm_page_free(m);
-			cnt.v_dfree++;
+			++cnt.v_dfree;
 			++pages_freed;
 		} else if (m->dirty == 0) {
 			vm_page_cache(m);
@@ -788,7 +786,7 @@ rescan0:
 			if (m->flags & PG_REFERENCED) {
 				refcount += 1;
 			}
-			refcount += pmap_ts_referenced(VM_PAGE_TO_PHYS(m));
+			refcount += pmap_tc_referenced(VM_PAGE_TO_PHYS(m));
 			if (refcount) {
 				m->act_count += ACT_ADVANCE + refcount;
 				if (m->act_count > ACT_MAX)