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authorJamie Gennis <jgennis@google.com>2012-11-21 15:04:25 -0800
committerArve Hjønnevåg <arve@android.com>2013-04-29 14:43:22 -0700
commitd34f20303f234fb6eae16548055766916cae7c2b (patch)
treef07973905b24cb353d5e5d77facf426a460b96a7
parent54eb16cc0dd5419116208d7f4ed0c49da3980a70 (diff)
downloadvexpress-lsk-d34f20303f234fb6eae16548055766916cae7c2b.tar.gz
trace: Add an option to show tgids in trace output
The tgids are tracked along side the saved_cmdlines tracking, and can be included in trace output by enabling the 'print-tgid' trace option. This is useful when doing post-processing of the trace data, as it allows events to be grouped by tgid. Change-Id: I52ed04c3a8ca7fddbb868b792ce5d21ceb76250e Signed-off-by: Jamie Gennis <jgennis@google.com>
-rw-r--r--kernel/trace/trace.c104
-rw-r--r--kernel/trace/trace.h2
-rw-r--r--kernel/trace/trace_output.c18
3 files changed, 117 insertions, 7 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 66338c4f7f4..0308e572cda 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -479,6 +479,7 @@ static const char *trace_options[] = {
"disable_on_free",
"irq-info",
"markers",
+ "print-tgid",
NULL
};
@@ -983,6 +984,7 @@ void tracing_reset_current_online_cpus(void)
static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
static unsigned map_cmdline_to_pid[SAVED_CMDLINES];
static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN];
+static unsigned saved_tgids[SAVED_CMDLINES];
static int cmdline_idx;
static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED;
@@ -1130,6 +1132,7 @@ static void trace_save_cmdline(struct task_struct *tsk)
}
memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN);
+ saved_tgids[idx] = tsk->tgid;
arch_spin_unlock(&trace_cmdline_lock);
}
@@ -1165,6 +1168,25 @@ void trace_find_cmdline(int pid, char comm[])
preempt_enable();
}
+int trace_find_tgid(int pid)
+{
+ unsigned map;
+ int tgid;
+
+ preempt_disable();
+ arch_spin_lock(&trace_cmdline_lock);
+ map = map_pid_to_cmdline[pid];
+ if (map != NO_CMDLINE_MAP)
+ tgid = saved_tgids[map];
+ else
+ tgid = -1;
+
+ arch_spin_unlock(&trace_cmdline_lock);
+ preempt_enable();
+
+ return tgid;
+}
+
void tracing_record_cmdline(struct task_struct *tsk)
{
if (atomic_read(&trace_record_cmdline_disabled) || !tracing_is_on())
@@ -2082,6 +2104,13 @@ static void print_func_help_header(struct trace_array *tr, struct seq_file *m)
seq_puts(m, "# | | | | |\n");
}
+static void print_func_help_header_tgid(struct trace_array *tr, struct seq_file *m)
+{
+ print_event_info(tr, m);
+ seq_puts(m, "# TASK-PID TGID CPU# TIMESTAMP FUNCTION\n");
+ seq_puts(m, "# | | | | | |\n");
+}
+
static void print_func_help_header_irq(struct trace_array *tr, struct seq_file *m)
{
print_event_info(tr, m);
@@ -2094,6 +2123,18 @@ static void print_func_help_header_irq(struct trace_array *tr, struct seq_file *
seq_puts(m, "# | | | |||| | |\n");
}
+static void print_func_help_header_irq_tgid(struct trace_array *tr, struct seq_file *m)
+{
+ print_event_info(tr, m);
+ seq_puts(m, "# _-----=> irqs-off\n");
+ seq_puts(m, "# / _----=> need-resched\n");
+ seq_puts(m, "# | / _---=> hardirq/softirq\n");
+ seq_puts(m, "# || / _--=> preempt-depth\n");
+ seq_puts(m, "# ||| / delay\n");
+ seq_puts(m, "# TASK-PID TGID CPU# |||| TIMESTAMP FUNCTION\n");
+ seq_puts(m, "# | | | | |||| | |\n");
+}
+
void
print_trace_header(struct seq_file *m, struct trace_iterator *iter)
{
@@ -2389,9 +2430,15 @@ void trace_default_header(struct seq_file *m)
} else {
if (!(trace_flags & TRACE_ITER_VERBOSE)) {
if (trace_flags & TRACE_ITER_IRQ_INFO)
- print_func_help_header_irq(iter->tr, m);
+ if (trace_flags & TRACE_ITER_TGID)
+ print_func_help_header_irq_tgid(iter->tr, m);
+ else
+ print_func_help_header_irq(iter->tr, m);
else
- print_func_help_header(iter->tr, m);
+ if (trace_flags & TRACE_ITER_TGID)
+ print_func_help_header_tgid(iter->tr, m);
+ else
+ print_func_help_header(iter->tr, m);
}
}
}
@@ -3074,9 +3121,53 @@ tracing_saved_cmdlines_read(struct file *file, char __user *ubuf,
}
static const struct file_operations tracing_saved_cmdlines_fops = {
- .open = tracing_open_generic,
- .read = tracing_saved_cmdlines_read,
- .llseek = generic_file_llseek,
+ .open = tracing_open_generic,
+ .read = tracing_saved_cmdlines_read,
+ .llseek = generic_file_llseek,
+};
+
+static ssize_t
+tracing_saved_tgids_read(struct file *file, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char *file_buf;
+ char *buf;
+ int len = 0;
+ int pid;
+ int i;
+
+ file_buf = kmalloc(SAVED_CMDLINES*(16+1+16), GFP_KERNEL);
+ if (!file_buf)
+ return -ENOMEM;
+
+ buf = file_buf;
+
+ for (i = 0; i < SAVED_CMDLINES; i++) {
+ int tgid;
+ int r;
+
+ pid = map_cmdline_to_pid[i];
+ if (pid == -1 || pid == NO_CMDLINE_MAP)
+ continue;
+
+ tgid = trace_find_tgid(pid);
+ r = sprintf(buf, "%d %d\n", pid, tgid);
+ buf += r;
+ len += r;
+ }
+
+ len = simple_read_from_buffer(ubuf, cnt, ppos,
+ file_buf, len);
+
+ kfree(file_buf);
+
+ return len;
+}
+
+static const struct file_operations tracing_saved_tgids_fops = {
+ .open = tracing_open_generic,
+ .read = tracing_saved_tgids_read,
+ .llseek = generic_file_llseek,
};
static ssize_t
@@ -5073,6 +5164,9 @@ static __init int tracer_init_debugfs(void)
trace_create_file("saved_cmdlines", 0444, d_tracer,
NULL, &tracing_saved_cmdlines_fops);
+ trace_create_file("saved_tgids", 0444, d_tracer,
+ NULL, &tracing_saved_tgids_fops);
+
trace_create_file("trace_clock", 0644, d_tracer, NULL,
&trace_clock_fops);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 2081971367e..183cfe8208d 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -574,6 +574,7 @@ static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
extern cycle_t ftrace_now(int cpu);
extern void trace_find_cmdline(int pid, char comm[]);
+extern int trace_find_tgid(int pid);
#ifdef CONFIG_DYNAMIC_FTRACE
extern unsigned long ftrace_update_tot_cnt;
@@ -786,6 +787,7 @@ enum trace_iterator_flags {
TRACE_ITER_STOP_ON_FREE = 0x400000,
TRACE_ITER_IRQ_INFO = 0x800000,
TRACE_ITER_MARKERS = 0x1000000,
+ TRACE_ITER_TGID = 0x2000000,
};
/*
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 697e88d1390..249e1e93698 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -660,11 +660,25 @@ int trace_print_context(struct trace_iterator *iter)
unsigned long secs, usec_rem;
char comm[TASK_COMM_LEN];
int ret;
+ int tgid;
trace_find_cmdline(entry->pid, comm);
- ret = trace_seq_printf(s, "%16s-%-5d [%03d] ",
- comm, entry->pid, iter->cpu);
+ ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
+ if (!ret)
+ return 0;
+
+ if (trace_flags & TRACE_ITER_TGID) {
+ tgid = trace_find_tgid(entry->pid);
+ if (tgid < 0)
+ ret = trace_seq_puts(s, "(-----) ");
+ else
+ ret = trace_seq_printf(s, "(%5d) ", tgid);
+ if (!ret)
+ return 0;
+ }
+
+ ret = trace_seq_printf(s, "[%03d] ", iter->cpu);
if (!ret)
return 0;