PERFORCE change 188779 for review

[Edward Tomasz Napierala]

http://p4web.freebsd.org/@@188779?ac=10

Change 188779 by trasz at trasz_victim on 2011/02/13 13:52:11

	Fix logic error that could make vm_daemon() to loop indefinitely.

Affected files ...

.. //depot/projects/soc2009/trasz_limits/sys/vm/vm_pageout.c#29 edit

Differences ...

==== //depot/projects/soc2009/trasz_limits/sys/vm/vm_pageout.c#29 (text+ko) ====

@@ -1636,7 +1636,7 @@
 	struct proc *p;
 	struct thread *td;
 	struct vmspace *vm;
-	int breakout, swapout_flags, tryagain;
+	int breakout, swapout_flags, tryagain, attempts;
 	uint64_t rsize, ravailable;
 
 	while (TRUE) {
@@ -1657,7 +1657,9 @@
 		 * process is swapped out -- deactivate pages
 		 */
 		tryagain = 0;
+		attempts = 0;
 again:
+		attempts++;
 		sx_slock(&allproc_lock);
 		FOREACH_PROC_IN_SYSTEM(p) {
 			vm_pindex_t limit, size;
@@ -1732,8 +1734,6 @@
 				 * been exceeded by some memory hog.  Don't
 				 * try to deactivate more than 1/4th of process'
 				 * resident set size.
-				 *
-				 * XXX: Reconsider.
 				 */
 				if (ravailable < rsize - (rsize / 4))
 					ravailable = rsize - (rsize / 4);
@@ -1746,19 +1746,18 @@
 				rusage_set(p, RUSAGE_RSS, rsize);
 				PROC_UNLOCK(p);
 				if (rsize > ravailable)
-					tryagain++;
-				if (tryagain > 20) {
-#if 0
-					printf("still too much: rsize = %ju, ravailable = %ju\n",
-					    (uintmax_t)rsize, (uintmax_t)ravailable);
+					tryagain = 1;
+				if (attempts == 10) {
+#if 1
+					printf("still too much: pid %d (%s), rsize = %ju, ravailable = %ju\n",
+					    p->p_pid, p->p_comm, (uintmax_t)rsize, (uintmax_t)ravailable);
 #endif
-					tryagain = 0;
 				}
 			}
 			vmspace_free(vm);
 		}
 		sx_sunlock(&allproc_lock);
-		if (tryagain != 0)
+		if (tryagain != 0 && attempts <= 10)
 			goto again;
 	}
 }