title: Linux kernel compile error Unsupported NR_CPUS for lb tracepoint
body: <p>I am trying to compile linux kernel 3.4.0 on Ubuntu 16.04, but I am getting an error: </p>
  
  <pre><code>In file included from kernel/fork.c:79:0:
  include/trace/events/sched.h:249:2: error: #error "Unsupported NR_CPUS for lb tracepoint."
   #error "Unsupported NR_CPUS for lb tracepoint."
    ^
  scripts/Makefile.build:307: recipe for target 'kernel/fork.o' failed
  </code></pre>
  
  <p>Any help is appreciated!</p>