svn commit: r324743 - head/sys/vm

[Alan Cox]

Author: alc
Date: Thu Oct 19 04:13:47 2017
New Revision: 324743
URL: https://svnweb.freebsd.org/changeset/base/324743

Log:
  Batch atomic updates to the number of active, inactive, and laundry
  pages by vm_object_terminate_pages().  For example, for a "buildworld"
  workload, this batching reduces vm_object_terminate_pages()'s average
  execution time by 12%.  (The total savings were about 11.7 billion
  processor cycles.)
  
  Reviewed by:	kib
  MFC after:	1 week

Modified:
  head/sys/vm/vm_object.c

Modified: head/sys/vm/vm_object.c
==============================================================================
--- head/sys/vm/vm_object.c	Thu Oct 19 03:38:53 2017	(r324742)
+++ head/sys/vm/vm_object.c	Thu Oct 19 04:13:47 2017	(r324743)
@@ -715,6 +715,7 @@ vm_object_terminate_pages(vm_object_t object)
 	vm_page_t p, p_next;
 	struct mtx *mtx, *mtx1;
 	struct vm_pagequeue *pq, *pq1;
+	int dequeued;
 
 	VM_OBJECT_ASSERT_WLOCKED(object);
 
@@ -739,6 +740,7 @@ vm_object_terminate_pages(vm_object_t object)
 				if (mtx != NULL)
 					mtx_unlock(mtx);
 				if (pq != NULL) {
+					vm_pagequeue_cnt_add(pq, dequeued);
 					vm_pagequeue_unlock(pq);
 					pq = NULL;
 				}
@@ -756,19 +758,27 @@ vm_object_terminate_pages(vm_object_t object)
 			    "page %p is not queued", p));
 			pq1 = vm_page_pagequeue(p);
 			if (pq != pq1) {
-				if (pq != NULL)
+				if (pq != NULL) {
+					vm_pagequeue_cnt_add(pq, dequeued);
 					vm_pagequeue_unlock(pq);
+				}
 				pq = pq1;
 				vm_pagequeue_lock(pq);
+				dequeued = 0;
 			}
+			p->queue = PQ_NONE;
+			TAILQ_REMOVE(&pq->pq_pl, p, plinks.q);
+			dequeued--;
 		}
 		if (vm_page_free_prep(p, true))
 			continue;
 unlist:
 		TAILQ_REMOVE(&object->memq, p, listq);
 	}
-	if (pq != NULL)
+	if (pq != NULL) {
+		vm_pagequeue_cnt_add(pq, dequeued);
 		vm_pagequeue_unlock(pq);
+	}
 	if (mtx != NULL)
 		mtx_unlock(mtx);