Messages in this thread Patch in this message | | | Date | Wed, 27 May 2009 17:10:37 +0800 | From | Xiao Guangrong <> | Subject | [PATCH] ftrace: add tracepoint for xtime |
| |
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
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> --- include/trace/events/xtime.h | 38 ++++++++++++++++++++++++++++++++++++++ kernel/time/ntp.c | 2 ++ kernel/time/timekeeping.c | 5 +++++ 3 files changed, 45 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..f07bb64 --- /dev/null +++ b/include/trace/events/xtime.h @@ -0,0 +1,38 @@ +#if !defined(_TRACE_XTIME_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_XTIME_H + +#include <linux/time.h> +#include <linux/tracepoint.h> + +#undef TRACE_SYSTEM +#define TRACE_SYSTEM xtime + +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 7fc6437..33db762 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -14,6 +14,7 @@ #include <linux/timex.h> #include <linux/time.h> #include <linux/mm.h> +#include <trace/events/xtime.h> /* * NTP timekeeping variables: @@ -220,6 +221,7 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer) break; } update_vsyscall(&xtime, clock); + trace_gtod_update_xtime(&xtime, &wall_to_monotonic); write_sequnlock(&xtime_lock); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index e8c77d9..798f93e 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -19,6 +19,9 @@ #include <linux/time.h> #include <linux/tick.h> +#define CREATE_TRACE_POINTS +#include <trace/events/xtime.h> + /* * This read-write spinlock protects us from races in SMP while @@ -171,6 +174,7 @@ int do_settimeofday(struct timespec *tv) ntp_clear(); update_vsyscall(&xtime, clock); + trace_gtod_update_xtime(&xtime, &wall_to_monotonic); write_sequnlock_irqrestore(&xtime_lock, flags); @@ -568,6 +572,7 @@ void update_wall_time(void) /* check to see if there is a new clocksource to use */ change_clocksource(); update_vsyscall(&xtime, clock); + trace_gtod_update_xtime(&xtime, &wall_to_monotonic); } /** -- 1.6.1.2
| |