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Commit 11e84acc authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Ingo Molnar
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tracing/function-graph-tracer: display unified style cmdline and pid 



Impact: extend function-graph output: let one know which thread called a function

This patch implements a helper function to print the couple cmdline/pid.
Its output is provided during task switching and on each row if the new
"funcgraph-proc" defualt-off option is set through trace_options file.

The output is center aligned and never exceeds 14 characters. The cmdline
is truncated over 7 chars.
But note that if the pid exceeds 6 characters, the column will overflow (but
the situation is abnormal).

Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 62679efe

kernel/trace/trace_functions_graph.c

+99 −14
Original line number Original line Diff line number Diff line
@@ -19,6 +19,7 @@ 
#define TRACE_GRAPH_PRINT_OVERRUN	0x1

#define TRACE_GRAPH_PRINT_OVERRUN	0x1

#define TRACE_GRAPH_PRINT_CPU		0x2

#define TRACE_GRAPH_PRINT_CPU		0x2

#define TRACE_GRAPH_PRINT_OVERHEAD	0x4

#define TRACE_GRAPH_PRINT_OVERHEAD	0x4

#define TRACE_GRAPH_PRINT_PROC		0x8





static struct tracer_opt trace_opts[] = {

static struct tracer_opt trace_opts[] = {

	/* Display overruns ? */

	/* Display overruns ? */
@@ -27,11 +28,13 @@ static struct tracer_opt trace_opts[] = { 
	{ TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },

	{ TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },

	/* Display Overhead ? */

	/* Display Overhead ? */

	{ TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },

	{ TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },

	/* Display proc name/pid */

	{ TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },

	{ } /* Empty entry */

	{ } /* Empty entry */

};

};





static struct tracer_flags tracer_flags = {

static struct tracer_flags tracer_flags = {

	/* Don't display overruns by default */

	/* Don't display overruns and proc by default */

	.val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD,

	.val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD,

	.opts = trace_opts

	.opts = trace_opts

};

};
@@ -104,23 +107,63 @@ print_graph_cpu(struct trace_seq *s, int cpu) 
	return TRACE_TYPE_HANDLED;

	return TRACE_TYPE_HANDLED;

}

}





#define TRACE_GRAPH_PROCINFO_LENGTH	14



static enum print_line_t

print_graph_proc(struct trace_seq *s, pid_t pid)

{

	int i;

	int ret;

	int len;

	char comm[8];

	int spaces = 0;

	/* sign + log10(MAX_INT) + '\0' */

	char pid_str[11];



	strncpy(comm, trace_find_cmdline(pid), 7);

	comm[7] = '\0';

	sprintf(pid_str, "%d", pid);



	/* 1 stands for the "-" character */

	len = strlen(comm) + strlen(pid_str) + 1;



	if (len < TRACE_GRAPH_PROCINFO_LENGTH)

		spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;



	/* First spaces to align center */

	for (i = 0; i < spaces / 2; i++) {

		ret = trace_seq_printf(s, " ");

		if (!ret)

			return TRACE_TYPE_PARTIAL_LINE;

	}



	ret = trace_seq_printf(s, "%s-%s", comm, pid_str);

	if (!ret)

		return TRACE_TYPE_PARTIAL_LINE;



	/* Last spaces to align center */

	for (i = 0; i < spaces - (spaces / 2); i++) {

		ret = trace_seq_printf(s, " ");

		if (!ret)

			return TRACE_TYPE_PARTIAL_LINE;

	}

	return TRACE_TYPE_HANDLED;

}







/* If the pid changed since the last trace, output this event */

/* If the pid changed since the last trace, output this event */

static int verif_pid(struct trace_seq *s, pid_t pid, int cpu)

static enum print_line_t

verif_pid(struct trace_seq *s, pid_t pid, int cpu)

{

{

	char *comm, *prev_comm;

	pid_t prev_pid;

	pid_t prev_pid;

	int ret;

	int ret;





	if (last_pid[cpu] != -1 && last_pid[cpu] == pid)

	if (last_pid[cpu] != -1 && last_pid[cpu] == pid)

		return 1;

		return TRACE_TYPE_HANDLED;





	prev_pid = last_pid[cpu];

	prev_pid = last_pid[cpu];

	last_pid[cpu] = pid;

	last_pid[cpu] = pid;





	comm = trace_find_cmdline(pid);

	prev_comm = trace_find_cmdline(prev_pid);



/*

/*

 * Context-switch trace line:

 * Context-switch trace line:
@@ -130,11 +173,31 @@ static int verif_pid(struct trace_seq *s, pid_t pid, int cpu) 




 */

 */

	ret = trace_seq_printf(s,

	ret = trace_seq_printf(s,

		" ------------------------------------------\n");

		"\n ------------------------------------------\n |");

	ret += trace_seq_printf(s, " | %d)  %s-%d  =>  %s-%d\n",

	if (!ret)

				  cpu, prev_comm, prev_pid, comm, pid);

		TRACE_TYPE_PARTIAL_LINE;

	ret += trace_seq_printf(s,



		" ------------------------------------------\n\n");

	ret = print_graph_cpu(s, cpu);

	if (ret == TRACE_TYPE_PARTIAL_LINE)

		TRACE_TYPE_PARTIAL_LINE;



	ret = print_graph_proc(s, prev_pid);

	if (ret == TRACE_TYPE_PARTIAL_LINE)

		TRACE_TYPE_PARTIAL_LINE;



	ret = trace_seq_printf(s, " => ");

	if (!ret)

		TRACE_TYPE_PARTIAL_LINE;



	ret = print_graph_proc(s, pid);

	if (ret == TRACE_TYPE_PARTIAL_LINE)

		TRACE_TYPE_PARTIAL_LINE;



	ret = trace_seq_printf(s,

		"\n ------------------------------------------\n\n");

	if (!ret)

		TRACE_TYPE_PARTIAL_LINE;



	return ret;

	return ret;

}

}
@@ -288,12 +351,23 @@ print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s, 
	struct trace_entry *ent = iter->ent;

	struct trace_entry *ent = iter->ent;





	/* Pid */

	/* Pid */

	if (!verif_pid(s, ent->pid, cpu))

	if (verif_pid(s, ent->pid, cpu) == TRACE_TYPE_PARTIAL_LINE)

		return TRACE_TYPE_PARTIAL_LINE;

		return TRACE_TYPE_PARTIAL_LINE;





	/* Cpu */

	/* Cpu */

	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {

	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {

		ret = print_graph_cpu(s, 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, ent->pid);

		if (ret == TRACE_TYPE_PARTIAL_LINE)

			return TRACE_TYPE_PARTIAL_LINE;



		ret = trace_seq_printf(s, " | ");

		if (!ret)

		if (!ret)

			return TRACE_TYPE_PARTIAL_LINE;

			return TRACE_TYPE_PARTIAL_LINE;

	}

	}
@@ -318,12 +392,23 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s, 
		duration = 9999999ULL;

		duration = 9999999ULL;





	/* Pid */

	/* Pid */

	if (!verif_pid(s, ent->pid, cpu))

	if (verif_pid(s, ent->pid, cpu) == TRACE_TYPE_PARTIAL_LINE)

		return TRACE_TYPE_PARTIAL_LINE;

		return TRACE_TYPE_PARTIAL_LINE;





	/* Cpu */

	/* Cpu */

	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {

	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {

		ret = print_graph_cpu(s, 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, ent->pid);

		if (ret == TRACE_TYPE_PARTIAL_LINE)

			return TRACE_TYPE_PARTIAL_LINE;



		ret = trace_seq_printf(s, " | ");

		if (!ret)

		if (!ret)

			return TRACE_TYPE_PARTIAL_LINE;

			return TRACE_TYPE_PARTIAL_LINE;

	}

	}