Re: Re: [PATCH 2/3] ftrace: add tracepoint for xtime

Zhaolei
2009-09-01T08:00:27Z

Hello, Thomas

I done this patchset to add walltime display for ftrace.
I think it will make ftrace more convenient to use.

To make it work, I rebased a patch from Xiao Guangrong to add tracepoint
into xtime, so I can use this feture for my code.

Could you have a look at this patch?

Thanks
Zhaolei

Steven Rostedt wrote:
> Thomas,
>
> This patch touches time keeping work. Can I get your ACK on it, or if it
> belongs to someone else, could you tell me who I need.
>
> Thanks,
>
> -- Steve
>
>
> On Tue, 25 Aug 2009, Zhaolei wrote:
>
>> From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
>>
>> This patch can trace current xtime and wall_to_monotonic. Then user can
>> use ctime() to convert them to wall time which is easier to be understood,
>> especially for flight-recorder which need to get trace event from a kernel
>> dump file.
>>
>> Example of ftrace output:
>> <idle>-0 [000] 20118.489849: gtod_update_xtime: xtime=1243265589.999999824 wall_to_monotonic=3051713268.744158739
>> <...>-4020 [001] 20118.489855: sys_open(filename: bf9e66e0, flags: 98800, mode: bf9e66e0)
>> <...>-4020 [001] 20118.489873: sys_open -> 0xffffffec
>>
>> ctime(1243265590) = date:Mon May 25 11:33:10 2009
>> So we can realize the task with pid 4020 open a file at
>> Mon May 25 11:33:10 2009
>>
>> Changelog:
>> v1->v2: Rebased by Zhao Lei <zhaolei@cn.fujitsu.com>
>>
>> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
>> Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
>> ---
>> include/trace/events/xtime.h | 38 ++++++++++++++++++++++++++++++++++++++
>> kernel/time/ntp.c | 4 ++++
>> kernel/time/timekeeping.c | 6 ++++++
>> 3 files changed, 48 insertions(+), 0 deletions(-)
>> create mode 100644 include/trace/events/xtime.h
>>
>> diff --git a/include/trace/events/xtime.h b/include/trace/events/xtime.h
>> new file mode 100644
>> index 0000000..398e679
>> --- /dev/null
>> +++ b/include/trace/events/xtime.h
>> @@ -0,0 +1,38 @@
>> +#undef TRACE_SYSTEM
>> +#define TRACE_SYSTEM xtime
>> +
>> +#if !defined(_TRACE_XTIME_H) || defined(TRACE_HEADER_MULTI_READ)
>> +#define _TRACE_XTIME_H
>> +
>> +#include <linux/time.h>
>> +#include <linux/tracepoint.h>
>> +
>> +TRACE_EVENT(gtod_update_xtime,
>> +
>> + TP_PROTO(struct timespec *xtime, struct timespec *wall_to_monotonic),
>> +
>> + TP_ARGS(xtime, wall_to_monotonic),
>> +
>> + TP_STRUCT__entry(
>> + __field( long, xtime_sec )
>> + __field( long, xtime_nsec )
>> + __field( long, wall_to_monotonic_sec )
>> + __field( long, wall_to_monotonic_nsec )
>> + ),
>> +
>> + TP_fast_assign(
>> + __entry->xtime_sec = xtime->tv_sec;
>> + __entry->xtime_nsec = xtime->tv_nsec;
>> + __entry->wall_to_monotonic_sec = wall_to_monotonic->tv_sec;
>> + __entry->wall_to_monotonic_nsec = wall_to_monotonic->tv_nsec;
>> + ),
>> +
>> + TP_printk("xtime=%ld.%09ld wall_to_monotonic=%ld.%09ld",
>> + __entry->xtime_sec, __entry->xtime_nsec,
>> + __entry->wall_to_monotonic_sec, __entry->wall_to_monotonic_nsec)
>> +);
>> +
>> +#endif /* _TRACE_XTIME_H */
>> +
>> +/* This part must be outside protection */
>> +#include <trace/define_trace.h>
>> diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
>> index 4800f93..fc2f13a 100644
>> --- a/kernel/time/ntp.c
>> +++ b/kernel/time/ntp.c
>> @@ -15,6 +15,8 @@
>> #include <linux/time.h>
>> #include <linux/mm.h>
>>
>> +#include <trace/events/xtime.h>
>> +
>> /*
>> * NTP timekeeping variables:
>> */
>> @@ -218,6 +220,8 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
>> break;
>> }
>>
>> + trace_gtod_update_xtime(&xtime, &wall_to_monotonic);
>> +
>> write_sequnlock(&xtime_lock);
>>
>> return res;
>> diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
>> index 03cbeb3..2e57a87 100644
>> --- a/kernel/time/timekeeping.c
>> +++ b/kernel/time/timekeeping.c
>> @@ -20,6 +20,9 @@
>> #include <linux/tick.h>
>> #include <linux/stop_machine.h>
>>
>> +#define CREATE_TRACE_POINTS
>> +#include <trace/events/xtime.h>
>> +
>> /* Structure holding internal timekeeping values. */
>> struct timekeeper {
>> /* Current clocksource used for timekeeping. */
>> @@ -338,6 +341,8 @@ int do_settimeofday(struct timespec *tv)
>>
>> update_vsyscall(&xtime, timekeeper.clock);
>>
>> + trace_gtod_update_xtime(&xtime, &wall_to_monotonic);
>> +
>> write_sequnlock_irqrestore(&xtime_lock, flags);
>>
>> /* signal hrtimers about time change */
>> @@ -811,6 +816,7 @@ void update_wall_time(void)
>>
>> /* check to see if there is a new clocksource to use */
>> update_vsyscall(&xtime, timekeeper.clock);
>> + trace_gtod_update_xtime(&xtime, &wall_to_monotonic);
>> }
>>
>> /**
>> --
>> 1.5.5.3
>>
>>