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* [PATCH 3/5] tracing/fastboot: Make the boot tracer use the cpu_clock
@ 2008-10-11 20:17 Frederic Weisbecker
  2008-10-21 12:47 ` Frédéric Weisbecker
  0 siblings, 1 reply; 2+ messages in thread
From: Frederic Weisbecker @ 2008-10-11 20:17 UTC (permalink / raw)
  To: Ingo Molnar; +Cc: Arjan van de Ven, linux-kernel

Make the boot tracer use the cpu_clock() rather than the ktime
API. This way we will be able to unify the time capture with 
the sched_switch tracer.
Also delete the duration attribute which is not needed and can be
retrieved at print time.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
---
 include/linux/ftrace.h    |    5 ++---
 init/main.c               |   25 ++++++++++++++++++-------
 kernel/trace/trace_boot.c |   18 ++++++++++--------
 3 files changed, 30 insertions(+), 18 deletions(-)

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 135a33f..36b570b 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -222,9 +222,8 @@ struct boot_trace {
 	pid_t			caller;
 	char 			func[KSYM_NAME_LEN];
 	int			result;
-	unsigned long long	duration;
-	ktime_t			calltime;
-	ktime_t			rettime;
+	unsigned long long	calltime;
+	unsigned long long	rettime;
 };
 
 #ifdef CONFIG_BOOT_TRACER
diff --git a/init/main.c b/init/main.c
index 98c05aa..bf13013 100644
--- a/init/main.c
+++ b/init/main.c
@@ -721,27 +721,38 @@ __setup("initcall_debug", initcall_debug_setup);
 int do_one_initcall(initcall_t fn)
 {
 	int count = preempt_count();
-	ktime_t delta;
+	ktime_t delta, t0, t1;
 	char msgbuf[64];
+	unsigned long long duration;
 	struct boot_trace it;
 
 	if (initcall_debug) {
+		long cpu;
 		it.caller = task_pid_nr(current);
 		printk("calling  %pF @ %i\n", fn, it.caller);
-		it.calltime = ktime_get();
+		t0 = ktime_get();
+		preempt_disable();
+		cpu = raw_smp_processor_id();
+		it.calltime = cpu_clock(cpu);
+		preempt_enable();
 		enable_boot_trace();
 	}
 
 	it.result = fn();
 
 	if (initcall_debug) {
-		it.rettime = ktime_get();
-		delta = ktime_sub(it.rettime, it.calltime);
-		it.duration = (unsigned long long) delta.tv64 >> 20;
+		long cpu;
+		disable_boot_trace();
+		t1 = ktime_get();
+		preempt_disable();
+		cpu = raw_smp_processor_id();
+		it.rettime = cpu_clock(cpu);
+		preempt_enable();
+		delta = ktime_sub(t1, t0);
+		duration = (unsigned long long) delta.tv64 >> 20;
 		printk("initcall %pF returned %d after %Ld msecs\n", fn,
-			it.result, it.duration);
+			it.result, duration);
 		trace_boot(&it, fn);
-		disable_boot_trace();
 	}
 
 	msgbuf[0] = 0;
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index bd5046c..20d326b 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -68,22 +68,24 @@ static enum print_line_t initcall_print_line(struct trace_iterator *iter)
 	struct trace_boot *field = (struct trace_boot *)entry;
 	struct boot_trace *it = &field->initcall;
 	struct trace_seq *s = &iter->seq;
-	struct timespec calltime = ktime_to_timespec(it->calltime);
-	struct timespec rettime = ktime_to_timespec(it->rettime);
+	unsigned long sec, nsec_rem;
+	unsigned long long duration = it->rettime - it->calltime;
 
 	if (entry->type == TRACE_BOOT) {
+		nsec_rem = do_div(it->calltime, 1000000000);
+		sec = (unsigned long) it->calltime;
 		ret = trace_seq_printf(s, "[%5ld.%09ld] calling  %s @ %i\n",
-					  calltime.tv_sec,
-					  calltime.tv_nsec,
-					  it->func, it->caller);
+					  sec, nsec_rem, it->func, it->caller);
 		if (!ret)
 			return TRACE_TYPE_PARTIAL_LINE;
 
+		nsec_rem = do_div(it->rettime, 1000000000);
+		sec = (unsigned long) it->rettime;
+		do_div(duration, 1000);
 		ret = trace_seq_printf(s, "[%5ld.%09ld] initcall %s "
 					  "returned %d after %lld msecs\n",
-					  rettime.tv_sec,
-					  rettime.tv_nsec,
-					  it->func, it->result, it->duration);
+					  sec, nsec_rem, it->func, it->result,
+					  duration);
 
 		if (!ret)
 			return TRACE_TYPE_PARTIAL_LINE;

^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH 3/5] tracing/fastboot: Make the boot tracer use the cpu_clock
  2008-10-11 20:17 [PATCH 3/5] tracing/fastboot: Make the boot tracer use the cpu_clock Frederic Weisbecker
@ 2008-10-21 12:47 ` Frédéric Weisbecker
  0 siblings, 0 replies; 2+ messages in thread
From: Frédéric Weisbecker @ 2008-10-21 12:47 UTC (permalink / raw)
  To: Ingo Molnar; +Cc: Arjan van de Ven, linux-kernel

2008/10/11 Frederic Weisbecker <fweisbec@gmail.com>:
> Make the boot tracer use the cpu_clock() rather than the ktime
> API. This way we will be able to unify the time capture with
> the sched_switch tracer.
> Also delete the duration attribute which is not needed and can be
> retrieved at print time.
>
> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
> Cc: Arjan van de Ven <arjan@linux.intel.com>
> ---
>  include/linux/ftrace.h    |    5 ++---
>  init/main.c               |   25 ++++++++++++++++++-------
>  kernel/trace/trace_boot.c |   18 ++++++++++--------
>  3 files changed, 30 insertions(+), 18 deletions(-)
>
> diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
> index 135a33f..36b570b 100644
> --- a/include/linux/ftrace.h
> +++ b/include/linux/ftrace.h
> @@ -222,9 +222,8 @@ struct boot_trace {
>        pid_t                   caller;
>        char                    func[KSYM_NAME_LEN];
>        int                     result;
> -       unsigned long long      duration;
> -       ktime_t                 calltime;
> -       ktime_t                 rettime;
> +       unsigned long long      calltime;
> +       unsigned long long      rettime;
>  };
>
>  #ifdef CONFIG_BOOT_TRACER
> diff --git a/init/main.c b/init/main.c
> index 98c05aa..bf13013 100644
> --- a/init/main.c
> +++ b/init/main.c
> @@ -721,27 +721,38 @@ __setup("initcall_debug", initcall_debug_setup);
>  int do_one_initcall(initcall_t fn)
>  {
>        int count = preempt_count();
> -       ktime_t delta;
> +       ktime_t delta, t0, t1;
>        char msgbuf[64];
> +       unsigned long long duration;
>        struct boot_trace it;
>
>        if (initcall_debug) {
> +               long cpu;
>                it.caller = task_pid_nr(current);
>                printk("calling  %pF @ %i\n", fn, it.caller);
> -               it.calltime = ktime_get();
> +               t0 = ktime_get();
> +               preempt_disable();
> +               cpu = raw_smp_processor_id();
> +               it.calltime = cpu_clock(cpu);
> +               preempt_enable();
>                enable_boot_trace();
>        }
>
>        it.result = fn();
>
>        if (initcall_debug) {
> -               it.rettime = ktime_get();
> -               delta = ktime_sub(it.rettime, it.calltime);
> -               it.duration = (unsigned long long) delta.tv64 >> 20;
> +               long cpu;
> +               disable_boot_trace();
> +               t1 = ktime_get();
> +               preempt_disable();
> +               cpu = raw_smp_processor_id();
> +               it.rettime = cpu_clock(cpu);
> +               preempt_enable();
> +               delta = ktime_sub(t1, t0);
> +               duration = (unsigned long long) delta.tv64 >> 20;
>                printk("initcall %pF returned %d after %Ld msecs\n", fn,
> -                       it.result, it.duration);
> +                       it.result, duration);
>                trace_boot(&it, fn);
> -               disable_boot_trace();
>        }
>
>        msgbuf[0] = 0;
> diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
> index bd5046c..20d326b 100644
> --- a/kernel/trace/trace_boot.c
> +++ b/kernel/trace/trace_boot.c
> @@ -68,22 +68,24 @@ static enum print_line_t initcall_print_line(struct trace_iterator *iter)
>        struct trace_boot *field = (struct trace_boot *)entry;
>        struct boot_trace *it = &field->initcall;
>        struct trace_seq *s = &iter->seq;
> -       struct timespec calltime = ktime_to_timespec(it->calltime);
> -       struct timespec rettime = ktime_to_timespec(it->rettime);
> +       unsigned long sec, nsec_rem;
> +       unsigned long long duration = it->rettime - it->calltime;
>
>        if (entry->type == TRACE_BOOT) {
> +               nsec_rem = do_div(it->calltime, 1000000000);
> +               sec = (unsigned long) it->calltime;
>                ret = trace_seq_printf(s, "[%5ld.%09ld] calling  %s @ %i\n",
> -                                         calltime.tv_sec,
> -                                         calltime.tv_nsec,
> -                                         it->func, it->caller);
> +                                         sec, nsec_rem, it->func, it->caller);
>                if (!ret)
>                        return TRACE_TYPE_PARTIAL_LINE;
>
> +               nsec_rem = do_div(it->rettime, 1000000000);
> +               sec = (unsigned long) it->rettime;
> +               do_div(duration, 1000);
>                ret = trace_seq_printf(s, "[%5ld.%09ld] initcall %s "
>                                          "returned %d after %lld msecs\n",
> -                                         rettime.tv_sec,
> -                                         rettime.tv_nsec,
> -                                         it->func, it->result, it->duration);
> +                                         sec, nsec_rem, it->func, it->result,
> +                                         duration);
>
>                if (!ret)
>                        return TRACE_TYPE_PARTIAL_LINE;
>

Please just ignore this patch. I think I will change a bit the design
of the boot tracer by sending
two types of entries: the call and the return. With this new approach,
I will be able to use the internal
timestamp of the ring buffer and stay consistent with the same used
for sched switch entries.

Thanks.

^ permalink raw reply	[flat|nested] 2+ messages in thread

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