From 3f0a525ebf4b8ef041a332bbe4a73aee94bb064b Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Mon, 10 Aug 2009 10:52:30 +0800 Subject: itimers: Add tracepoints for itimer Add tracepoints for all itimer variants: ITIMER_REAL, ITIMER_VIRTUAL and ITIMER_PROF. [ tglx: Fixed comments and made the output more readable, parseable and consistent. Replaced pid_vnr by pid_nr because the hrtimer callback can happen in any namespace ] Signed-off-by: Xiao Guangrong Cc: Steven Rostedt Cc: Frederic Weisbecker Cc: Mathieu Desnoyers Cc: Anton Blanchard Cc: Peter Zijlstra Cc: KOSAKI Motohiro Cc: Zhaolei LKML-Reference: <4A7F8B6E.2010109@cn.fujitsu.com> Signed-off-by: Thomas Gleixner --- include/trace/events/timer.h | 66 ++++++++++++++++++++++++++++++++++++++++++++ kernel/itimer.c | 5 ++++ kernel/posix-cpu-timers.c | 7 ++++- 3 files changed, 77 insertions(+), 1 deletion(-) diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h index df3c07fa0cb8..1844c48d640e 100644 --- a/include/trace/events/timer.h +++ b/include/trace/events/timer.h @@ -270,6 +270,72 @@ TRACE_EVENT(hrtimer_cancel, TP_printk("hrtimer %p", __entry->timer) ); +/** + * itimer_state - called when itimer is started or canceled + * @which: name of the interval timer + * @value: the itimers value, itimer is canceled if value->it_value is + * zero, otherwise it is started + * @expires: the itimers expiry time + */ +TRACE_EVENT(itimer_state, + + TP_PROTO(int which, const struct itimerval *const value, + cputime_t expires), + + TP_ARGS(which, value, expires), + + TP_STRUCT__entry( + __field( int, which ) + __field( cputime_t, expires ) + __field( long, value_sec ) + __field( long, value_usec ) + __field( long, interval_sec ) + __field( long, interval_usec ) + ), + + TP_fast_assign( + __entry->which = which; + __entry->expires = expires; + __entry->value_sec = value->it_value.tv_sec; + __entry->value_usec = value->it_value.tv_usec; + __entry->interval_sec = value->it_interval.tv_sec; + __entry->interval_usec = value->it_interval.tv_usec; + ), + + TP_printk("which %d, expires %lu, it_value %lu.%lu, it_interval %lu.%lu", + __entry->which, __entry->expires, + __entry->value_sec, __entry->value_usec, + __entry->interval_sec, __entry->interval_usec) +); + +/** + * itimer_expire - called when itimer expires + * @which: type of the interval timer + * @pid: pid of the process which owns the timer + * @now: current time, used to calculate the latency of itimer + */ +TRACE_EVENT(itimer_expire, + + TP_PROTO(int which, struct pid *pid, cputime_t now), + + TP_ARGS(which, pid, now), + + TP_STRUCT__entry( + __field( int , which ) + __field( pid_t, pid ) + __field( cputime_t, now ) + ), + + TP_fast_assign( + __entry->which = which; + __entry->now = now; + __entry->pid = pid_nr(pid); + ), + + TP_printk("which %d, pid %d, now %lu", __entry->which, + (int) __entry->pid, __entry->now) +); + #endif /* _TRACE_TIMER_H */ /* This part must be outside protection */ diff --git a/kernel/itimer.c b/kernel/itimer.c index 8078a32d3b10..b03451ede528 100644 --- a/kernel/itimer.c +++ b/kernel/itimer.c @@ -12,6 +12,7 @@ #include #include #include +#include #include @@ -122,6 +123,7 @@ enum hrtimer_restart it_real_fn(struct hrtimer *timer) struct signal_struct *sig = container_of(timer, struct signal_struct, real_timer); + trace_itimer_expire(ITIMER_REAL, sig->leader_pid, 0); kill_pid_info(SIGALRM, SEND_SIG_PRIV, sig->leader_pid); return HRTIMER_NORESTART; @@ -166,6 +168,8 @@ static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, } it->expires = nval; it->incr = ninterval; + trace_itimer_state(clock_id == CPUCLOCK_VIRT ? + ITIMER_VIRTUAL : ITIMER_PROF, value, nval); spin_unlock_irq(&tsk->sighand->siglock); @@ -217,6 +221,7 @@ again: } else tsk->signal->it_real_incr.tv64 = 0; + trace_itimer_state(ITIMER_REAL, value, 0); spin_unlock_irq(&tsk->sighand->siglock); break; case ITIMER_VIRTUAL: diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 12161f74744e..5c9dc228747b 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -8,6 +8,7 @@ #include #include #include +#include /* * Called after updating RLIMIT_CPU to set timer expiration if necessary. @@ -1090,9 +1091,13 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, cputime_one_jiffy); it->error -= onecputick; } - } else + } else { it->expires = cputime_zero; + } + trace_itimer_expire(signo == SIGPROF ? + ITIMER_PROF : ITIMER_VIRTUAL, + tsk->signal->leader_pid, cur_time); __group_send_sig_info(signo, SEND_SIG_PRIV, tsk); } -- cgit v1.2.3