-bash-3.2# cat /proc/latency_trace 
preemption latency trace v1.1.5 on 2.6.23.1-rt5frodantest
--------------------------------------------------------------------
 latency: 3462 us, #4/4, CPU#0 | (M:rt VP:0, KP:0, SP:1 HP:1)
    -----------------
    | task: softirq-timer/0-5 (uid:0 nice:-5 policy:1 rt_prio:50)
    -----------------

                 _------=> CPU#            
                / _-----=> irqs-off        
               | / _----=> need-resched    
               || / _---=> hardirq/softirq 
               ||| / _--=> preempt-depth   
               |||| /                      
               |||||     delay             
   cmd     pid ||||| time  |   caller      
      \   /    |||||   \   |   /           
softirq--5     0D...    8us!: common_interrupt+0x24/0x40 (<0>)
softirq--5     0D... 3432us+: restore_nocheck+0x12/0x15 (<0>)
softirq--5     0D... 3448us : trace_hardirqs_on+0xb1/0xd0 (restore_nocheck+0x12/0x15)