tFULL PRODUCT VERSION :
java version "1.7.0_60"
Java(TM) SE Runtime Environment (build 1.7.0_60-b19)
Java HotSpot(TM) 64-Bit Server VM (build 24.60-b09, mixed mode)

FULL OS VERSION :
2.6.18 x86_64

EXTRA RELEVANT SYSTEM CONFIGURATION :
Huge pages are manually configured and works correctly with JDK 6 and up to JDK 7u55 (inclusive). Switching to 7u60 introduces the behavior of silently falling back

A DESCRIPTION OF THE PROBLEM :
Starting with 7u60 the combination of LargePages, G1GC, and a heap of 8GB or more causes the JVM to silently fall back to small pages.

THE PROBLEM WAS REPRODUCIBLE WITH -Xint FLAG: Yes

THE PROBLEM WAS REPRODUCIBLE WITH -server FLAG: Yes

REGRESSION. Last worked in version 7u60

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Super simple code to just let the JVM hang out so you can go to another window and check the hugepages utilization:

import javax.net.*;

class Hello {
    public static void main(String[] argv) throws Exception {
        System.out.println("Hello!");
        Thread.sleep(1000000);
    }
}

Works up to 1MB below the 8GB mark:

/apollo/env/BigBirdRequestRouterService/jdk/bin/java -Xms8191m -Xmx8191m -XX:+UseLargePages -XX:+AlwaysPreTouch -XX:+UseG1GC Hello
Hello!

(in another window)
cat /proc/meminfo |grep Huge
HugePages_Total: 8704
HugePages_Free: 8694
HugePages_Rsvd: 3622
Hugepagesize: 2048 kB

At 8GB (and higher) the hugepages just stop working and silently fall back to small pages:

/apollo/env/BigBirdRequestRouterService/jdk/bin/java -Xms8191m -Xmx8191m -XX:+UseLargePages -XX:+AlwaysPreTouch -XX:+UseG1GC Hello

cat /proc/meminfo |grep Huge
HugePages_Total: 8704
HugePages_Free: 8696
HugePages_Rsvd: 0
Hugepagesize: 2048 kB


However if I remove UseG1GC but leave the 8GB heap, it uses the huge pages:

java -Xms8g -Xmx8g -XX:+UseLargePages -XX:+AlwaysPreTouch Hello
Hello!

cat /proc/meminfo |grep Huge
HugePages_Total: 8704
HugePages_Free: 4596
HugePages_Rsvd: 160
Hugepagesize: 2048 kB


EXPECTED VERSUS ACTUAL BEHAVIOR :
I expect the huge/large pages to be used even with G1GC and a heap of 8GB+
ERROR MESSAGES/STACK TRACES THAT OCCUR :
No errors, it silently falls back.

REPRODUCIBILITY :
This bug can be reproduced always.

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See reproduction steps
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CUSTOMER SUBMITTED WORKAROUND :
I haven't been able to find one.