svn commit: r236685 - stable/8/sys/vm

[Maksim Yevmenkin]

Author: emax
Date: Wed Jun  6 16:20:59 2012
New Revision: 236685
URL: http://svn.freebsd.org/changeset/base/236685

Log:
  MFC r235854
  
  Seems applicable here as well.
  
  Tweak condition for disabling allocation from per-CPU buckets in
  low memory situation. I've observed a situation where per-CPU
  allocations were disabled while there were enough free cached pages.
  Basically, cnt.v_free_count was sitting stable at a value lower
  than cnt.v_free_min and that caused massive performance drop.
  
  Reviewed by:	alc
  Requested by:	Andrew Boyer aboyer at averesystems dot com

Modified:
  stable/8/sys/vm/uma_core.c
Directory Properties:
  stable/8/sys/   (props changed)

Modified: stable/8/sys/vm/uma_core.c
==============================================================================
--- stable/8/sys/vm/uma_core.c	Wed Jun  6 16:01:45 2012	(r236684)
+++ stable/8/sys/vm/uma_core.c	Wed Jun  6 16:20:59 2012	(r236685)
@@ -267,10 +267,7 @@ SYSCTL_PROC(_vm, OID_AUTO, zone_stats, C
 static void
 bucket_enable(void)
 {
-	if (cnt.v_free_count < cnt.v_free_min)
-		bucketdisable = 1;
-	else
-		bucketdisable = 0;
+	bucketdisable = vm_page_count_min();
 }
 
 /*