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| author | Lai Jiangshan <laijs@cn.fujitsu.com> | 2009-03-30 13:48:00 +0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-04-07 13:59:23 +0200 |
| commit | cf8e3474654f20433aab9aa35826d43b5f245008 (patch) | |
| tree | bbb3e87ca324ae4192fd524c0777047ee075c5d9 /kernel/trace/trace.c | |
| parent | 301fd748e2c81e78e74edbc694a64caa7b95dda2 (diff) | |
| download | blackbird-op-linux-cf8e3474654f20433aab9aa35826d43b5f245008.tar.gz blackbird-op-linux-cf8e3474654f20433aab9aa35826d43b5f245008.zip | |
tracing: fix incorrect return type of ns2usecs()
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: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <49D05D10.4030009@cn.fujitsu.com>
Reported-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index a0174a40c563..457dd8c97e0d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -147,8 +147,7 @@ static int __init set_ftrace_dump_on_oops(char *str) } __setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops); -long -ns2usecs(cycle_t nsec) +unsigned long long ns2usecs(cycle_t nsec) { nsec += 500; do_div(nsec, 1000); |
