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Message-ID: <492F3076.7050104@gmail.com>
Date: Fri, 28 Nov 2008 00:42:46 +0100
From: Frederic Weisbecker <fweisbec@...il.com>
To: Ingo Molnar <mingo@...e.hu>
CC: Steven Rostedt <rostedt@...dmis.org>,
Tim Bird <tim.bird@...sony.com>,
Peter Zijlstra <a.p.zijlstra@...llo.nl>,
Linux Kernel <linux-kernel@...r.kernel.org>
Subject: [PATCH] tracing/function-graph-tracer: adjustments of the trace informations
Impact: increase visibility of the output
This patch applies various changes.
_CPU is now a decimal number, followed by a parenthesis.
_Overhead is now on the second column (gives a good visibility)
_Cost is now on the third column, can't exceed 9999.99 us. It is followed
by a virtual line based on a "|" character.
_Functions calls are now the last column on the right. This way, we haven't
dynamic column (which flow is harder to follow) on its right.
_CPU and Overhead have their own option flag. They are default-on but you can
disable them easily:
echo nofuncgraph-cpu > trace_options
echo nofuncgraph-overhead > trace_options
TODO:
_ Refactoring of the thread switch output.
_ Give a default-off option to output the thread and its pid on each row.
_ Provide headers
_ ....
Here is an example of the new trace style (a wider one is provided in attachment):
0) | mutex_unlock() {
0) 0.639 us | __mutex_unlock_slowpath();
0) 1.607 us | }
0) | remove_wait_queue() {
0) 0.616 us | _spin_lock_irqsave();
0) 0.616 us | _spin_unlock_irqrestore();
0) 2.779 us | }
0) 0.495 us | n_tty_set_room();
0) ! 9999.999 us | }
0) | tty_ldisc_deref() {
0) 0.615 us | _spin_lock_irqsave();
0) 0.616 us | _spin_unlock_irqrestore();
0) 2.793 us | }
0) | current_fs_time() {
0) 0.488 us | current_kernel_time();
0) 0.495 us | timespec_trunc();
0) 2.486 us | }
0) ! 9999.999 us | }
0) ! 9999.999 us | }
0) ! 9999.999 us | }
0) | sys_read() {
0) 0.796 us | fget_light();
0) | vfs_read() {
0) | rw_verify_area() {
0) | security_file_permission() {
0) 0.488 us | cap_file_permission();
0) 1.720 us | }
0) 3. 4 us | }
0) | tty_read() {
0) 0.488 us | tty_paranoia_check();
0) | tty_ldisc_ref_wait() {
0) | tty_ldisc_try() {
0) 0.615 us | _spin_lock_irqsave();
0) 0.615 us | _spin_unlock_irqrestore();
0) 5.436 us | }
0) 6.427 us | }
Signed-off-by: Frederic Weisbecker <fweisbec@...il.com>
---
kernel/trace/trace_functions_graph.c | 142 ++++++++++++++++++++++------------
1 files changed, 93 insertions(+), 49 deletions(-)
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index b958d60..596a3ee 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -14,20 +14,25 @@
#include "trace.h"
#define TRACE_GRAPH_INDENT 2
-/* Spaces between function call and time duration */
-#define TRACE_GRAPH_TIMESPACE_ENTRY " "
-/* Spaces between function call and closing braces */
-#define TRACE_GRAPH_TIMESPACE_RET " "
+/* Flag options */
#define TRACE_GRAPH_PRINT_OVERRUN 0x1
+#define TRACE_GRAPH_PRINT_CPU 0x2
+#define TRACE_GRAPH_PRINT_OVERHEAD 0x4
+
static struct tracer_opt trace_opts[] = {
- /* Display overruns or not */
- { TRACER_OPT(overrun, TRACE_GRAPH_PRINT_OVERRUN) },
+ /* Display overruns ? */
+ { TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
+ /* Display CPU ? */
+ { TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
+ /* Display Overhead ? */
+ { TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
{ } /* Empty entry */
};
static struct tracer_flags tracer_flags = {
- .val = 0, /* Don't display overruns by default */
+ /* Don't display overruns by default */
+ .val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD,
.opts = trace_opts
};
@@ -56,6 +61,36 @@ static void graph_trace_reset(struct trace_array *tr)
unregister_ftrace_graph();
}
+static inline int log10_cpu(int nb)
+{
+ if (nb / 100)
+ return 3;
+ if (nb / 10)
+ return 2;
+ return 1;
+}
+
+static enum print_line_t
+print_graph_cpu(struct trace_seq *s, int cpu)
+{
+ int i;
+ int ret;
+ int log10_this = log10_cpu(cpu);
+ int log10_all = log10_cpu(cpus_weight_nr(cpu_online_map));
+
+
+ for (i = 0; i < log10_all - log10_this; i++) {
+ ret = trace_seq_printf(s, " ");
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
+ ret = trace_seq_printf(s, "%d) ", cpu);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ return TRACE_TYPE_HANDLED;
+}
+
+
/* If the pid changed since the last trace, output this event */
static int verif_pid(struct trace_seq *s, pid_t pid, int cpu)
{
@@ -67,8 +102,7 @@ static int verif_pid(struct trace_seq *s, pid_t pid, int cpu)
last_pid[cpu] = pid;
comm = trace_find_cmdline(pid);
- return trace_seq_printf(s, "\nCPU[%03d] "
- " ------------8<---------- thread %s-%d"
+ return trace_seq_printf(s, "\n------------8<---------- thread %s-%d"
" ------------8<----------\n\n",
cpu, comm, pid);
}
@@ -86,7 +120,7 @@ trace_branch_is_leaf(struct trace_iterator *iter,
if (!ring_iter)
return false;
- event = ring_buffer_iter_peek(iter->buffer_iter[iter->cpu], NULL);
+ event = ring_buffer_iter_peek(ring_iter, NULL);
if (!event)
return false;
@@ -108,7 +142,7 @@ static inline int
print_graph_duration(unsigned long long duration, struct trace_seq *s)
{
unsigned long nsecs_rem = do_div(duration, 1000);
- return trace_seq_printf(s, "+ %llu.%lu us\n", duration, nsecs_rem);
+ return trace_seq_printf(s, "%4llu.%3lu us | ", duration, nsecs_rem);
}
/* Signal a overhead of time execution to the output */
@@ -136,8 +170,8 @@ print_graph_entry_leaf(struct trace_iterator *iter,
struct ring_buffer_event *event;
struct ftrace_graph_ent *call;
unsigned long long duration;
- int i;
int ret;
+ int i;
event = ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
ret_entry = ring_buffer_event_data(event);
@@ -145,8 +179,19 @@ print_graph_entry_leaf(struct trace_iterator *iter,
call = &entry->graph_ent;
duration = graph_ret->rettime - graph_ret->calltime;
+ /* Must not exceed 8 characters: 9999.999 us */
+ if (duration > 10000000ULL)
+ duration = 9999999ULL;
+
/* Overhead */
- ret = print_graph_overhead(duration, s);
+ if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
+ ret = print_graph_overhead(duration, s);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
+
+ /* Duration */
+ ret = print_graph_duration(duration, s);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
@@ -161,16 +206,7 @@ print_graph_entry_leaf(struct trace_iterator *iter,
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
- ret = trace_seq_printf(s, "();");
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
-
- /* Duration */
- ret = trace_seq_printf(s, TRACE_GRAPH_TIMESPACE_ENTRY);
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
-
- ret = print_graph_duration(duration, s);
+ ret = trace_seq_printf(s, "();\n");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
@@ -186,9 +222,14 @@ print_graph_entry_nested(struct ftrace_graph_ent_entry *entry,
struct ftrace_graph_ent *call = &entry->graph_ent;
/* No overhead */
- ret = trace_seq_printf(s, " ");
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
+ if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
+ ret = trace_seq_printf(s, " ");
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
+
+ /* No time */
+ ret = trace_seq_printf(s, " | ");
/* Function */
for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
@@ -201,12 +242,7 @@ print_graph_entry_nested(struct ftrace_graph_ent_entry *entry,
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
- ret = trace_seq_printf(s, "() {");
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
-
- /* No duration to print at this state */
- ret = trace_seq_printf(s, TRACE_GRAPH_TIMESPACE_ENTRY "-\n");
+ ret = trace_seq_printf(s, "() {\n");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
@@ -220,12 +256,16 @@ print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
int ret;
struct trace_entry *ent = iter->ent;
+ /* Pid */
if (!verif_pid(s, ent->pid, cpu))
return TRACE_TYPE_PARTIAL_LINE;
- ret = trace_seq_printf(s, "CPU[%03d] ", cpu);
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
+ /* Cpu */
+ if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
+ ret = print_graph_cpu(s, cpu);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
if (trace_branch_is_leaf(iter, field))
return print_graph_entry_leaf(iter, field, s);
@@ -242,17 +282,30 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
int ret;
unsigned long long duration = trace->rettime - trace->calltime;
+ /* Must not exceed 8 characters: xxxx.yyy us */
+ if (duration > 10000000ULL)
+ duration = 9999999ULL;
+
/* Pid */
if (!verif_pid(s, ent->pid, cpu))
return TRACE_TYPE_PARTIAL_LINE;
/* Cpu */
- ret = trace_seq_printf(s, "CPU[%03d] ", cpu);
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
+ if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
+ ret = print_graph_cpu(s, cpu);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
/* Overhead */
- ret = print_graph_overhead(duration, s);
+ if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
+ ret = print_graph_overhead(duration, s);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
+
+ /* Duration */
+ ret = print_graph_duration(duration, s);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
@@ -263,16 +316,7 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
return TRACE_TYPE_PARTIAL_LINE;
}
- ret = trace_seq_printf(s, "} ");
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
-
- /* Duration */
- ret = trace_seq_printf(s, TRACE_GRAPH_TIMESPACE_RET);
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
-
- ret = print_graph_duration(duration, s);
+ ret = trace_seq_printf(s, "}\n");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
--
1.5.2.5
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