tomcat sloooow to start, smartos, kvm: urandom?

A fresh installation of CentOS 7 in a SmartOS KVM virtual machine using a dataset (     image_uuid: d8e65ea2-1f3e-11e5-8557-6b43e0a88b38).
CentOS updated just after the installation.

• apache-tomcat-7.0.64
• Java(TM) SE Runtime Environment (build 1.7.0_80-b15)

I noticed that Tomcat, at startup was very very very, help me, very slow to start.

I used strace to look at what was happening (even if I don't understand anything).

I got a lot of

[pid  1279] futex(0x7f5a880a7154, FUTEX_WAIT_BITSET_PRIVATE, 1, {348, 455527976}, ffffffff) = -1 ETIMEDOUT (Connection timed out)

[pid  1279] futex(0x7f5a880a7128, FUTEX_WAKE_PRIVATE, 1) = 0

Just googled around. I found something similar.

So the solution is: to add the following option to java in the tomcat startup script

-Djava.security.egd=file:/dev/urandom

 (like CATALINA_OPTS="$CATALINA_OPTS -Djava.security.egd=file:/dev/./urandom").

Who knows?