svn commit: r306749 - user/alc/PQ_LAUNDRY/sys/vm

[Alan Cox]

Author: alc
Date: Thu Oct  6 03:14:08 2016
New Revision: 306749
URL: https://svnweb.freebsd.org/changeset/base/306749

Log:
  In contrast to HEAD, the PQ_LAUNDRY page daemon should pause() after a
  level == 1 pass.
  
  Reviewed by:	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	Thu Oct  6 01:52:00 2016	(r306748)
+++ user/alc/PQ_LAUNDRY/sys/vm/vm_pageout.c	Thu Oct  6 03:14:08 2016	(r306749)
@@ -1244,8 +1244,8 @@ dolaundry:
 /*
  *	vm_pageout_scan does the dirty work for the pageout daemon.
  *
- *	pass 0 - Update active LRU/deactivate pages
- *	pass 1 - Free inactive pages
+ *	pass == 0: Update active LRU/deactivate pages
+ *	pass >= 1: Free inactive pages
  *
  * Returns true if pass was zero or enough pages were freed by the inactive
  * queue scan to meet the target.
@@ -1954,13 +1954,13 @@ vm_pageout_worker(void *arg)
 			 * thread during the previous scan, which must have
 			 * been a level 0 scan, or vm_pageout_wanted was
 			 * already set and the scan failed to free enough
-			 * pages.  If we haven't yet performed a level >= 2
-			 * scan (unlimited dirty cleaning), then upgrade the
-			 * level and scan again now.  Otherwise, sleep a bit
-			 * and try again later.
+			 * pages.  If we haven't yet performed a level >= 1
+			 * (page reclamation) scan, then increase the level
+			 * and scan again now.  Otherwise, sleep a bit and
+			 * try again later.
 			 */
 			mtx_unlock(&vm_page_queue_free_mtx);
-			if (pass > 1)
+			if (pass >= 1)
 				pause("psleep", hz / 2);
 			pass++;
 		} else {