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Bug ID: 6783381 NUMA allocator: don't pretouch eden space with UseNUMA
6783381 : NUMA allocator: don't pretouch eden space with UseNUMA

Details
Type:
Enhancement
Submit Date:
2008-12-10
Status:
Resolved
Updated Date:
2010-04-03
Project Name:
JDK
Resolved Date:
2009-02-11
Component:
hotspot
OS:
generic
Sub-Component:
gc
CPU:
generic
Priority:
P4
Resolution:
Fixed
Affected Versions:
hs14
Fixed Versions:
hs15

Related Reports
Backport:
JDK-2173039 - NUMA allocator: don't pretouch eden space with UseNUMA
Backport:
JDK-2180454 - NUMA allocator: don't pretouch eden space with UseNUMA

Sub Tasks

Description
With +AlwaysPreTouch and +UseNUMA the space that will be occupied by eden is first pretouched and then all the pages a uncommitted when the NUMA-aware allocator initialized essentially discarding the work.

Comments
EVALUATION

http://hg.openjdk.java.net/jdk7/hotspot-gc/hotspot/rev/4e400c36026f
2009-01-28 
SUGGESTED FIX

Move pretouching into MutableSpace and do the work for each of the spaces separately.
Also make from,to and old spaces interleaved -- as demonstrated by John Coomes that adds about 5% to specjbb performance. Maintain interleaving during resizing, while limiting the amount of work done per GC cycle.
2008-12-10


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