Problem reserving enough space for Java object heap since stretch upgrade

[Adam Rosi-Kessel <adam@rosi-kessel.org>]

I have been unable to execute Java with >=2048M memory allocation since 
upgrading to stretch. I've changed nothing in my configuration otherwise.

I have plenty of RAM:

# free
              total        used        free      shared buff/cache   
available
Mem:        5168396     3326140      245712 85320     1596544     1227812
Swap:       2255616      259204     1996412

# ulimit -v
unlimited

# java -Xmx2048M
Error occurred during initialization of VM
Could not reserve enough space for 2097152KB object heap

# ls -l /etc/alternatives/java
lrwxrwxrwx 1 root root 45 Jun 27 20:45 /etc/alternatives/java -> 
/usr/lib/jvm/java-8-openjdk-i386/jre/bin/java

But the same problem occurs when I switch to other Java alternatives. 
(openjdk-8-jre version = 8u131-b11-2).

Interestingly, if I set ulimit -v to something other than 'unlimited' 
but higher than the amount requested for the java process, it works:

# ulimit -v 2097153
# java -Xmx2048M

(no errors)

But shouldn't "unlimited" be higher than any arbitrary value I put 
there? Also, for Java programs that are run as daemons from /etc/init.d, 
I have been unable to figure out how to get the arbitrary ulimit -v 
setting to "stick".

TIA for any suggestions for how to fix or troubleshoot.