From f8b755ac8e0cc3f330269e4c4504514f987167a2 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Tue, 9 Dec 2008 23:55:25 +0100
Subject: [PATCH] tracing/function-graph-tracer: Output arrows signal on
hardirq call/return
Impact: make more obvious the hardirq calls in the output
When a hardirq is triggered inside the codeflow on output, we have
now two arrows that indicate the entry and return of the hardirq.
0) | bit_waitqueue() {
0) 0.880 us | __phys_addr();
0) 2.699 us | }
0) | __wake_up_bit() {
0) ==========> | smp_apic_timer_interrupt() {
0) 0.797 us | native_apic_mem_write();
0) 0.715 us | exit_idle();
0) | irq_enter() {
0) 0.722 us | idle_cpu();
0) 5.519 us | }
0) | hrtimer_interrupt() {
0) | ktime_get() {
0) | ktime_get_ts() {
0) 0.805 us | getnstimeofday();
[...]
0) ! 108.528 us | }
0) | irq_exit() {
0) | do_softirq() {
0) | __do_softirq() {
0) 0.895 us | __local_bh_disable();
0) | run_timer_softirq() {
0) 0.827 us | hrtimer_run_pending();
0) 1.226 us | _spin_lock_irq();
0) | _spin_unlock_irq() {
0) 6.550 us | }
0) 0.924 us | _local_bh_enable();
0) + 12.129 us | }
0) + 13.911 us | }
0) 0.707 us | idle_cpu();
0) + 17.009 us | }
0) ! 137.419 us | }
0) <========== |
0) 1.045 us | }
0) ! 148.908 us | }
0) ! 151.022 us | }
0) ! 153.022 us | }
0) 0.963 us | journal_mark_dirty();
0) 0.925 us | __brelse();
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
kernel/trace/trace_functions_graph.c | 66 ++++++++++++++++++++++++++--
1 file changed, 62 insertions(+), 4 deletions(-)
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index af60eef4cbcc..4bf39fcae97a 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -231,6 +231,49 @@ trace_branch_is_leaf(struct trace_iterator *iter,
return true;
}
+static enum print_line_t
+print_graph_irq(struct trace_seq *s, unsigned long addr,
+ enum trace_type type, int cpu, pid_t pid)
+{
+ int ret;
+
+ if (addr < (unsigned long)__irqentry_text_start ||
+ addr >= (unsigned long)__irqentry_text_end)
+ return TRACE_TYPE_UNHANDLED;
+
+ if (type == TRACE_GRAPH_ENT) {
+ ret = trace_seq_printf(s, "==========> | ");
+ } else {
+ /* Cpu */
+ if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
+ ret = print_graph_cpu(s, cpu);
+ if (ret == TRACE_TYPE_PARTIAL_LINE)
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
+ /* Proc */
+ if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
+ ret = print_graph_proc(s, pid);
+ if (ret == TRACE_TYPE_PARTIAL_LINE)
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ ret = trace_seq_printf(s, " | ");
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
+
+ /* No overhead */
+ if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
+ ret = trace_seq_printf(s, " ");
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
+
+ ret = trace_seq_printf(s, "<========== |\n");
+ }
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ return TRACE_TYPE_HANDLED;
+}
static enum print_line_t
print_graph_duration(unsigned long long duration, struct trace_seq *s)
@@ -344,7 +387,7 @@ print_graph_entry_leaf(struct trace_iterator *iter,
static enum print_line_t
print_graph_entry_nested(struct ftrace_graph_ent_entry *entry,
- struct trace_seq *s)
+ struct trace_seq *s, pid_t pid, int cpu)
{
int i;
int ret;
@@ -357,8 +400,18 @@ print_graph_entry_nested(struct ftrace_graph_ent_entry *entry,
return TRACE_TYPE_PARTIAL_LINE;
}
- /* No time */
- ret = trace_seq_printf(s, " | ");
+ /* Interrupt */
+ ret = print_graph_irq(s, call->func, TRACE_GRAPH_ENT, cpu, pid);
+ if (ret == TRACE_TYPE_UNHANDLED) {
+ /* No time */
+ ret = trace_seq_printf(s, " | ");
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ } else {
+ if (ret == TRACE_TYPE_PARTIAL_LINE)
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
+
/* Function */
for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
@@ -410,7 +463,7 @@ print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
if (trace_branch_is_leaf(iter, field))
return print_graph_entry_leaf(iter, field, s);
else
- return print_graph_entry_nested(field, s);
+ return print_graph_entry_nested(field, s, iter->ent->pid, cpu);
}
@@ -474,6 +527,11 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
+
+ ret = print_graph_irq(s, trace->func, TRACE_GRAPH_RET, cpu, ent->pid);
+ if (ret == TRACE_TYPE_PARTIAL_LINE)
+ return TRACE_TYPE_PARTIAL_LINE;
+
return TRACE_TYPE_HANDLED;
}