cassandra git commit: Fix comment about ParallelGCThreads

[sl...@apache.org]

Repository: cassandra
Updated Branches:
  refs/heads/cassandra-3.0 0c04a6bc5 -> 039ff1f88


Fix comment about ParallelGCThreads

patch by zznate; reviewed by pauloricardomg for CASSANDRA-10702


Project: http://git-wip-us.apache.org/repos/asf/cassandra/repo
Commit: http://git-wip-us.apache.org/repos/asf/cassandra/commit/039ff1f8
Tree: http://git-wip-us.apache.org/repos/asf/cassandra/tree/039ff1f8
Diff: http://git-wip-us.apache.org/repos/asf/cassandra/diff/039ff1f8

Branch: refs/heads/cassandra-3.0
Commit: 039ff1f8831129676b7e13cd0f9dd48451be9aa9
Parents: 0c04a6b
Author: Sylvain Lebresne <sy...@datastax.com>
Authored: Fri Nov 20 13:19:46 2015 +0100
Committer: Sylvain Lebresne <sy...@datastax.com>
Committed: Fri Nov 20 13:19:46 2015 +0100

----------------------------------------------------------------------
 conf/jvm.options | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/cassandra/blob/039ff1f8/conf/jvm.options
----------------------------------------------------------------------
diff --git a/conf/jvm.options b/conf/jvm.options
index 60f0f10..c5d3d95 100644
--- a/conf/jvm.options
+++ b/conf/jvm.options
@@ -85,9 +85,12 @@
 # until the heap is 70% full. The default in Hotspot 8u40 is 40%.
 #-XX:InitiatingHeapOccupancyPercent=70
 
-# The JVM maximum is 8 PGC threads and 1/4 of that for ConcGC.
-# Machines with > 10 cores may need additional threads. Increase to <= full cores.
+# For systems with > 8 cores, the default ParallelGCThreads is 5/8 the number of logical cores.
+# Otherwise equal to the number of cores when 8 or less.
+# Machines with > 10 cores should try setting these to <= full cores.
 #-XX:ParallelGCThreads=16
+# By default, ConcGCThreads is 1/4 of ParallelGCThreads.
+# Setting both to the same value can reduce STW durations.
 #-XX:ConcGCThreads=16
 
 ### GC logging options -- uncomment to enable