p:dataList multiple refresh

Question

Hello everybody I'm using a p:dataList and each time I use a p:commmandButton inside the dataList, it refreshes about 8 times ! the method which return the List is called again and again. But not the first time when the component is loaded.

<p:dataList value="#{formBean.parentCharactersListEdit}" 
            var="chara" id="testList" itemType="none">
     <f:facet name="header">test </f:facet>
     <div>
        <p:commandButton immediate="true" process="@this" 
           icon="fa fa-group" actionListener="#{formBean.test}"/>
     </div>
</p:dataList>

I don't know whats wrong in my implementation. Same issue with p:commandLink.

Thanks for help.