EAP 7 JSP performance is degraded in ImportHandler.resolveClass

Issue

• Upgrading from EAP 6 to EAP 7, we see performance of our JSPs is considerably reduced. Requests are consistently shown processing in ImportHandler calls from javax.servlet.jsp.el.ScopedAttributeELResolver:

"default task-115" #363 prio=5 os_prio=0 tid=0x00005570e60b2800 nid=0x1fe61 waiting on condition [0x00007f236df97000]
   java.lang.Thread.State: RUNNABLE
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:348)
    at org.jboss.modules.ClassLoaderLocalLoader.loadClassLocal(ClassLoaderLocalLoader.java:59)
    at org.jboss.modules.Module.loadModuleClass(Module.java:753)
    at org.jboss.modules.ModuleClassLoader.findClass(ModuleClassLoader.java:247)
    at org.jboss.modules.ConcurrentClassLoader.performLoadClassUnchecked(ConcurrentClassLoader.java:410)
    at org.jboss.modules.ConcurrentClassLoader.performLoadClass(ConcurrentClassLoader.java:398)
    at org.jboss.modules.ConcurrentClassLoader.loadClass(ConcurrentClassLoader.java:116)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:348)
    at javax.el.ImportHandler.getClassFor(ImportHandler.java:169)
    at javax.el.ImportHandler.resolveClassFor(ImportHandler.java:145)
    at javax.el.ImportHandler.resolveClass(ImportHandler.java:109)
    at javax.servlet.jsp.el.ScopedAttributeELResolver.getValue(ScopedAttributeELResolver.java:93)
    at org.apache.jasper.el.JasperELResolver.getValue(JasperELResolver.java:110)
    at com.sun.el.parser.AstIdentifier.getValue(AstIdentifier.java:91)
    at com.sun.el.parser.AstEqual.getValue(AstEqual.java:34)
    at com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:183)
    at org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate(PageContextImpl.java:917)