Messages in this thread Patch in this message | | | Date | Tue, 25 Aug 2009 16:14:02 +0800 | From | Zhaolei <> | Subject | [PATCH 2/3] ftrace: add tracepoint for xtime |
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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
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