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From: Changbin Du <changbin.du@gmail.com>
To: rostedt@goodmis.org
Cc: mingo@redhat.com, corbet@lwn.net, linux-doc@vger.kernel.org,
	linux-kernel@vger.kernel.org, Changbin Du <changbin.du@gmail.com>
Subject: [PATCH 1/5] function_graph: Support displaying relative timestamp
Date: Tue,  1 Jan 2019 23:46:10 +0800	[thread overview]
Message-ID: <20190101154614.8887-2-changbin.du@gmail.com> (raw)
In-Reply-To: <20190101154614.8887-1-changbin.du@gmail.com>

When function_graph is used for latency tracers, relative timestamp
is more straightforward than absolute timestamp as function trace
does. This change adds relative timestamp support to function_graph
and applies to latency tracers (wakeup and irqsoff).

Signed-off-by: Changbin Du <changbin.du@gmail.com>
---
 kernel/trace/trace.h                 |  9 +++++----
 kernel/trace/trace_functions_graph.c | 25 +++++++++++++++++++++++++
 kernel/trace/trace_irqsoff.c         |  2 +-
 kernel/trace/trace_sched_wakeup.c    |  2 +-
 4 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 08900828d282..a34fa5e76abb 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -855,10 +855,11 @@ static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
 #define TRACE_GRAPH_PRINT_PROC          0x8
 #define TRACE_GRAPH_PRINT_DURATION      0x10
 #define TRACE_GRAPH_PRINT_ABS_TIME      0x20
-#define TRACE_GRAPH_PRINT_IRQS          0x40
-#define TRACE_GRAPH_PRINT_TAIL          0x80
-#define TRACE_GRAPH_SLEEP_TIME		0x100
-#define TRACE_GRAPH_GRAPH_TIME		0x200
+#define TRACE_GRAPH_PRINT_REL_TIME      0x40
+#define TRACE_GRAPH_PRINT_IRQS          0x80
+#define TRACE_GRAPH_PRINT_TAIL          0x100
+#define TRACE_GRAPH_SLEEP_TIME          0x200
+#define TRACE_GRAPH_GRAPH_TIME          0x400
 #define TRACE_GRAPH_PRINT_FILL_SHIFT	28
 #define TRACE_GRAPH_PRINT_FILL_MASK	(0x3 << TRACE_GRAPH_PRINT_FILL_SHIFT)
 
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index c2af1560e856..16ebbdd7b22e 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -500,6 +500,17 @@ static void print_graph_abs_time(u64 t, struct trace_seq *s)
 			 (unsigned long)t, usecs_rem);
 }
 
+static void
+print_graph_rel_time(struct trace_iterator *iter, struct trace_seq *s)
+{
+	unsigned long long usecs;
+
+	usecs = iter->ts - iter->trace_buffer->time_start;
+	do_div(usecs, NSEC_PER_USEC);
+
+	trace_seq_printf(s, "%9llu us |  ", usecs);
+}
+
 static void
 print_graph_irq(struct trace_iterator *iter, unsigned long addr,
 		enum trace_type type, int cpu, pid_t pid, u32 flags)
@@ -517,6 +528,10 @@ print_graph_irq(struct trace_iterator *iter, unsigned long addr,
 		if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
 			print_graph_abs_time(iter->ts, s);
 
+		/* Relative time */
+		if (flags & TRACE_GRAPH_PRINT_REL_TIME)
+			print_graph_rel_time(iter, s);
+
 		/* Cpu */
 		if (flags & TRACE_GRAPH_PRINT_CPU)
 			print_graph_cpu(s, cpu);
@@ -725,6 +740,10 @@ print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
 	if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
 		print_graph_abs_time(iter->ts, s);
 
+	/* Relative time */
+	if (flags & TRACE_GRAPH_PRINT_REL_TIME)
+		print_graph_rel_time(iter, s);
+
 	/* Cpu */
 	if (flags & TRACE_GRAPH_PRINT_CPU)
 		print_graph_cpu(s, cpu);
@@ -1101,6 +1120,8 @@ static void print_lat_header(struct seq_file *s, u32 flags)
 
 	if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
 		size += 16;
+	if (flags & TRACE_GRAPH_PRINT_REL_TIME)
+		size += 16;
 	if (flags & TRACE_GRAPH_PRINT_CPU)
 		size += 4;
 	if (flags & TRACE_GRAPH_PRINT_PROC)
@@ -1125,6 +1146,8 @@ static void __print_graph_headers_flags(struct trace_array *tr,
 	seq_putc(s, '#');
 	if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
 		seq_puts(s, "     TIME       ");
+	if (flags & TRACE_GRAPH_PRINT_REL_TIME)
+		seq_puts(s, "   REL TIME     ");
 	if (flags & TRACE_GRAPH_PRINT_CPU)
 		seq_puts(s, " CPU");
 	if (flags & TRACE_GRAPH_PRINT_PROC)
@@ -1139,6 +1162,8 @@ static void __print_graph_headers_flags(struct trace_array *tr,
 	seq_putc(s, '#');
 	if (flags & TRACE_GRAPH_PRINT_ABS_TIME)
 		seq_puts(s, "      |         ");
+	if (flags & TRACE_GRAPH_PRINT_REL_TIME)
+		seq_puts(s, "      |         ");
 	if (flags & TRACE_GRAPH_PRINT_CPU)
 		seq_puts(s, " |  ");
 	if (flags & TRACE_GRAPH_PRINT_PROC)
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index d3294721f119..e6a62e7c6b69 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -238,7 +238,7 @@ static void irqsoff_trace_close(struct trace_iterator *iter)
 
 #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_CPU | \
 			    TRACE_GRAPH_PRINT_PROC | \
-			    TRACE_GRAPH_PRINT_ABS_TIME | \
+			    TRACE_GRAPH_PRINT_REL_TIME | \
 			    TRACE_GRAPH_PRINT_DURATION)
 
 static enum print_line_t irqsoff_print_line(struct trace_iterator *iter)
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 4ea7e6845efb..b6c5fa10347e 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -180,7 +180,7 @@ static void wakeup_trace_close(struct trace_iterator *iter)
 }
 
 #define GRAPH_TRACER_FLAGS (TRACE_GRAPH_PRINT_PROC | \
-			    TRACE_GRAPH_PRINT_ABS_TIME | \
+			    TRACE_GRAPH_PRINT_REL_TIME | \
 			    TRACE_GRAPH_PRINT_DURATION)
 
 static enum print_line_t wakeup_print_line(struct trace_iterator *iter)
-- 
2.17.1


  reply	other threads:[~2019-01-01 15:47 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-01 15:46 [PATCH 0/5] Improve the latency tracers Changbin Du
2019-01-01 15:46 ` Changbin Du [this message]
2019-01-01 15:46 ` [PATCH 2/5] sched/tracing: Show more info for funcgraph wakeup tracers Changbin Du
2019-01-01 15:46 ` [PATCH 3/5] sched/tracing: Put a margin between flags and duration for " Changbin Du
2019-01-01 15:46 ` [PATCH 4/5] sched/tracing: Show stacktrace " Changbin Du
2019-01-16  3:25   ` Steven Rostedt
2019-01-16 16:04     ` Changbin Du
2019-01-01 15:46 ` [PATCH 5/5] trace/doc: Add latency tracer funcgraph example Changbin Du
2019-01-12  4:05 ` [PATCH 0/5] Improve the latency tracers Changbin Du
2019-01-14 15:00   ` Steven Rostedt

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