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From: Alan Cox <alc@FreeBSD.org>
Date: Mon, 8 Aug 2016 01:01:05 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-user@freebsd.org
Subject: svn commit: r303820 - user/alc/PQ_LAUNDRY/sys/vm
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Author: alc
Date: Mon Aug  8 01:01:05 2016
New Revision: 303820
URL: https://svnweb.freebsd.org/changeset/base/303820

Log:
  Avoid division by zero without putting a stop to laundering.
  
  Discussed with:	markj

Modified:
  user/alc/PQ_LAUNDRY/sys/vm/vm_pageout.c

Modified: user/alc/PQ_LAUNDRY/sys/vm/vm_pageout.c
==============================================================================
--- user/alc/PQ_LAUNDRY/sys/vm/vm_pageout.c	Sun Aug  7 23:04:46 2016	(r303819)
+++ user/alc/PQ_LAUNDRY/sys/vm/vm_pageout.c	Mon Aug  8 01:01:05 2016	(r303820)
@@ -1130,7 +1130,7 @@ vm_pageout_laundry_worker(void *arg)
 		ninact = vm_cnt.v_inactive_count;
 		nlaundry = vm_cnt.v_laundry_count;
 		wakeups = VM_METER_PCPU_CNT(v_pdwakeups);
-		if (target == 0 && ninact > 0 && wakeups != gen &&
+		if (target == 0 && wakeups != gen &&
 		    nlaundry * bkgrd_launder_ratio >= ninact) {
 			gen = wakeups;
 
@@ -1152,6 +1152,8 @@ vm_pageout_laundry_worker(void *arg)
 			 */
 			target = vm_cnt.v_free_target -
 			    vm_pageout_wakeup_thresh;
+			if (ninact == 0)
+				ninact = 1;
 			target = nlaundry * (u_int)target / ninact / 10;
 			if (target == 0)
 				target = 1;