itimers: Add tracepoints for itimer (3f0a525e) · Commits · 戴 / test

include/trace/events/timer.h

+66 −0

Original line number	Diff line number	Diff line
		@@ -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 */

kernel/itimer.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -12,6 +12,7 @@
		#include <linux/time.h>
		#include <linux/posix-timers.h>
		#include <linux/hrtimer.h>
		#include <trace/events/timer.h>

		#include <asm/uaccess.h>

		@@ -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:

kernel/posix-cpu-timers.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -8,6 +8,7 @@
		#include <linux/math64.h>
		#include <asm/uaccess.h>
		#include <linux/kernel_stat.h>
		#include <trace/events/timer.h>

		/*
		* 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);
		}

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