svn commit: r236269 - stable/9/sys/vm

[Maksim Yevmenkin]

Author: emax
Date: Wed May 30 00:38:24 2012
New Revision: 236269
URL: http://svn.freebsd.org/changeset/base/236269

Log:
  MFC r235854
  
  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@

Modified:
  stable/9/sys/vm/uma_core.c
Directory Properties:
  stable/9/sys/   (props changed)

Modified: stable/9/sys/vm/uma_core.c
==============================================================================
--- stable/9/sys/vm/uma_core.c	Wed May 30 00:27:12 2012	(r236268)
+++ stable/9/sys/vm/uma_core.c	Wed May 30 00:38:24 2012	(r236269)
@@ -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();
 }
 
 /*