• Lai Jiangshan's avatar
    tracing: fix incorrect return type of ns2usecs() · cf8e3474
    Lai Jiangshan authored
    
    
    Impact: fix time output bug in 32bits system
    
    ns2usecs() returns 'long', it's incorrect.
    
    (In i386)
    ...
              <idle>-0     [000]   521.442100: _spin_lock <-tick_do_update_jiffies64
              <idle>-0     [000]   521.442101: do_timer <-tick_do_update_jiffies64
              <idle>-0     [000]   521.442102: update_wall_time <-do_timer
              <idle>-0     [000]   521.442102: update_xtime_cache <-update_wall_time
    ....
    (It always print the time less than 2200 seconds besides ...)
    Because 'long' is 32bits in i386. ( (1<<31) useconds is about 2200 seconds)
    
    ...
              <idle>-0     [001] 4154502640.134759: rcu_bh_qsctr_inc <-__do_softirq
              <idle>-0     [001] 4154502640.134760: _local_bh_enable <-__do_softirq
              <idle>-0     [001] 4154502640.134761: idle_cpu <-irq_exit
    ...
    (very large value)
    Because 'long' is a signed type and it is 32bits in i386.
    
    Changes in v2:
    return 'unsigned long long' instead of 'cycle_t'
    Signed-off-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
    LKML-Reference: <49D05D10.4030009@cn.fujitsu.com>
    Reported-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
    Acked-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
    Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    cf8e3474