[PATCH] tracing/function-branch-tracer: enhancements for the traceoutput
From: Frederic Weisbecker
Date: Wed Nov 26 2008 - 19:46:50 EST
Impact: enhancement
This patch applies some ideas of Ingo Molnar and Steven Rostedt.
* Output leaf functions in one line with parenthesis, semicolon and duration
output.
* Add a second column (after cpu) for an overhead sign.
if duration > 100 us, "!"
if duration > 10 us, "+"
else " "
* Print output in us with remaining nanosec: u.n
* Print duration on the right end, following the indentation of the functions.
Use also visual clues: "-" on entry call (no duration to output) and "+" on
return (duration output).
The name of the tracer has been fixed as well: function-branch becomes
function_branch.
Here is an example of the new output:
CPU[000] dequeue_entity() { -
CPU[000] update_curr() { -
CPU[000] update_min_vruntime(); + 0.512 us
CPU[000] } + 1.504 us
CPU[000] clear_buddies(); + 0.481 us
CPU[000] update_min_vruntime(); + 0.504 us
CPU[000] } + 4.557 us
CPU[000] hrtick_update() { -
CPU[000] hrtick_start_fair(); + 0.489 us
CPU[000] } + 1.443 us
CPU[000] + } + 14.655 us
CPU[000] + } + 15.678 us
CPU[000] + } + 16.686 us
CPU[000] msecs_to_jiffies(); + 0.481 us
CPU[000] put_prev_task_fair(); + 0.504 us
CPU[000] pick_next_task_fair(); + 0.482 us
CPU[000] pick_next_task_rt(); + 0.504 us
CPU[000] pick_next_task_fair(); + 0.481 us
CPU[000] pick_next_task_idle(); + 0.489 us
CPU[000] _spin_trylock(); + 0.655 us
CPU[000] _spin_unlock(); + 0.609 us
CPU[000] ------------8<---------- thread bash-2794 ------------8<----------
CPU[000] finish_task_switch() { -
CPU[000] _spin_unlock_irq(); + 0.722 us
CPU[000] } + 2.369 us
CPU[000] ! } + 501972.605 us
CPU[000] ! } + 501973.763 us
CPU[000] copy_from_read_buf() { -
CPU[000] _spin_lock_irqsave(); + 0.670 us
CPU[000] _spin_unlock_irqrestore(); + 0.699 us
CPU[000] copy_to_user() { -
CPU[000] might_fault() { -
CPU[000] __might_sleep(); + 0.503 us
CPU[000] } + 1.632 us
CPU[000] __copy_to_user_ll(); + 0.542 us
CPU[000] } + 3.858 us
CPU[000] tty_audit_add_data() { -
CPU[000] _spin_lock_irq(); + 0.609 us
CPU[000] _spin_unlock_irq(); + 0.624 us
CPU[000] } + 3.196 us
CPU[000] _spin_lock_irqsave(); + 0.624 us
CPU[000] _spin_unlock_irqrestore(); + 0.625 us
CPU[000] + } + 13.611 us
CPU[000] copy_from_read_buf() { -
CPU[000] _spin_lock_irqsave(); + 0.624 us
CPU[000] _spin_unlock_irqrestore(); + 0.616 us
CPU[000] } + 2.820 us
CPU[000]
Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
---
kernel/trace/trace_functions_graph.c | 168 ++++++++++++++++++++++++++++++++--
1 files changed, 159 insertions(+), 9 deletions(-)
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index d31d695..b958d60 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -14,6 +14,10 @@
#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 " "
#define TRACE_GRAPH_PRINT_OVERRUN 0x1
static struct tracer_opt trace_opts[] = {
@@ -63,26 +67,130 @@ 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]"
+ return trace_seq_printf(s, "\nCPU[%03d] "
" ------------8<---------- thread %s-%d"
" ------------8<----------\n\n",
cpu, comm, pid);
}
+static bool
+trace_branch_is_leaf(struct trace_iterator *iter,
+ struct ftrace_graph_ent_entry *curr)
+{
+ struct ring_buffer_iter *ring_iter;
+ struct ring_buffer_event *event;
+ struct ftrace_graph_ret_entry *next;
+
+ ring_iter = iter->buffer_iter[iter->cpu];
+
+ if (!ring_iter)
+ return false;
+
+ event = ring_buffer_iter_peek(iter->buffer_iter[iter->cpu], NULL);
+
+ if (!event)
+ return false;
+
+ next = ring_buffer_event_data(event);
+
+ if (next->ent.type != TRACE_GRAPH_RET)
+ return false;
+
+ if (curr->ent.pid != next->ent.pid ||
+ curr->graph_ent.func != next->ret.func)
+ return false;
+
+ return true;
+}
+
+
+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);
+}
+
+/* Signal a overhead of time execution to the output */
+static int
+print_graph_overhead(unsigned long long duration, struct trace_seq *s)
+{
+ /* Duration exceeded 100 msecs */
+ if (duration > 100000ULL)
+ return trace_seq_printf(s, "! ");
+
+ /* Duration exceeded 10 msecs */
+ if (duration > 10000ULL)
+ return trace_seq_printf(s, "+ ");
+
+ return trace_seq_printf(s, " ");
+}
+
+/* Case of a leaf function on its call entry */
static enum print_line_t
-print_graph_entry(struct ftrace_graph_ent *call, struct trace_seq *s,
- struct trace_entry *ent, int cpu)
+print_graph_entry_leaf(struct trace_iterator *iter,
+ struct ftrace_graph_ent_entry *entry, struct trace_seq *s)
{
+ struct ftrace_graph_ret_entry *ret_entry;
+ struct ftrace_graph_ret *graph_ret;
+ struct ring_buffer_event *event;
+ struct ftrace_graph_ent *call;
+ unsigned long long duration;
int i;
int ret;
- if (!verif_pid(s, ent->pid, cpu))
+ event = ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
+ ret_entry = ring_buffer_event_data(event);
+ graph_ret = &ret_entry->ret;
+ call = &entry->graph_ent;
+ duration = graph_ret->rettime - graph_ret->calltime;
+
+ /* Overhead */
+ ret = print_graph_overhead(duration, s);
+ if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
- ret = trace_seq_printf(s, "CPU[%03d] ", cpu);
+ /* Function */
+ for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
+ ret = trace_seq_printf(s, " ");
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
+
+ ret = seq_print_ip_sym(s, call->func, 0);
+ 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);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t
+print_graph_entry_nested(struct ftrace_graph_ent_entry *entry,
+ struct trace_seq *s)
+{
+ int i;
+ int ret;
+ struct ftrace_graph_ent *call = &entry->graph_ent;
+
+ /* No overhead */
+ ret = trace_seq_printf(s, " ");
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ /* Function */
for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
ret = trace_seq_printf(s, " ");
if (!ret)
@@ -93,26 +201,62 @@ print_graph_entry(struct ftrace_graph_ent *call, struct trace_seq *s,
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
- ret = trace_seq_printf(s, "() {\n");
+ 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");
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+
return TRACE_TYPE_HANDLED;
}
static enum print_line_t
+print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
+ struct trace_iterator *iter, int cpu)
+{
+ int ret;
+ struct trace_entry *ent = iter->ent;
+
+ 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;
+
+ if (trace_branch_is_leaf(iter, field))
+ return print_graph_entry_leaf(iter, field, s);
+ else
+ return print_graph_entry_nested(field, s);
+
+}
+
+static enum print_line_t
print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
struct trace_entry *ent, int cpu)
{
int i;
int ret;
+ unsigned long long duration = trace->rettime - trace->calltime;
+ /* 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;
+ /* Overhead */
+ ret = print_graph_overhead(duration, s);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ /* Closing brace */
for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
ret = trace_seq_printf(s, " ");
if (!ret)
@@ -123,10 +267,16 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
- ret = trace_seq_printf(s, "%llu\n", trace->rettime - trace->calltime);
+ /* Duration */
+ ret = trace_seq_printf(s, TRACE_GRAPH_TIMESPACE_RET);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ ret = print_graph_duration(duration, s);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
+ /* Overrun */
if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) {
ret = trace_seq_printf(s, " (Overruns: %lu)\n",
trace->overrun);
@@ -146,7 +296,7 @@ print_graph_function(struct trace_iterator *iter)
case TRACE_GRAPH_ENT: {
struct ftrace_graph_ent_entry *field;
trace_assign_type(field, entry);
- return print_graph_entry(&field->graph_ent, s, entry,
+ return print_graph_entry(field, s, iter,
iter->cpu);
}
case TRACE_GRAPH_RET: {
@@ -160,7 +310,7 @@ print_graph_function(struct trace_iterator *iter)
}
static struct tracer graph_trace __read_mostly = {
- .name = "function-graph",
+ .name = "function_graph",
.init = graph_trace_init,
.reset = graph_trace_reset,
.print_line = print_graph_function,
--
1.5.2.5
--
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