Re: [PATCH] perf: ftrace: add graph tracer options args/retval/retval-hex/retaddr

[duchangbin <changbin.du@huawei.com>]

Kindly ping.

On Fri, Jun 13, 2025 at 07:40:47PM +0800, Changbin Du wrote:
> This change adds support for new funcgraph tracer options funcgraph-args,
> funcgraph-retval, funcgraph-retval-hex and funcgraph-retaddr.
> 
> The new added options are:
>   - args       : Show function arguments.
>   - retval     : Show function return value.
>   - retval-hex : Show function return value in hexadecimal format.
>   - retaddr    : Show function return address.
> 
>  # ./perf ftrace -G vfs_write --graph-opts retval,retaddr
>  # tracer: function_graph
>  #
>  # CPU  DURATION                  FUNCTION CALLS
>  # |     |   |                     |   |   |   |
>  5)               |  mutex_unlock() { /* <-rb_simple_write+0xda/0x150 */
>  5)   0.188 us    |    local_clock(); /* <-lock_release+0x2ad/0x440 ret=0x3bf2a3cf90e */
>  5)               |    rt_mutex_slowunlock() { /* <-rb_simple_write+0xda/0x150 */
>  5)               |      _raw_spin_lock_irqsave() { /* <-rt_mutex_slowunlock+0x4f/0x200 */
>  5)   0.123 us    |        preempt_count_add(); /* <-_raw_spin_lock_irqsave+0x23/0x90 ret=0x0 */
>  5)   0.128 us    |        local_clock(); /* <-__lock_acquire.isra.0+0x17a/0x740 ret=0x3bf2a3cfc8b */
>  5)   0.086 us    |        do_raw_spin_trylock(); /* <-_raw_spin_lock_irqsave+0x4a/0x90 ret=0x1 */
>  5)   0.845 us    |      } /* _raw_spin_lock_irqsave ret=0x292 */
>  5)               |      _raw_spin_unlock_irqrestore() { /* <-rt_mutex_slowunlock+0x191/0x200 */
>  5)   0.097 us    |        local_clock(); /* <-lock_release+0x2ad/0x440 ret=0x3bf2a3cff1f */
>  5)   0.086 us    |        do_raw_spin_unlock(); /* <-_raw_spin_unlock_irqrestore+0x23/0x60 ret=0x1 */
>  5)   0.104 us    |        preempt_count_sub(); /* <-_raw_spin_unlock_irqrestore+0x35/0x60 ret=0x0 */
>  5)   0.726 us    |      } /* _raw_spin_unlock_irqrestore ret=0x80000000 */
>  5)   1.881 us    |    } /* rt_mutex_slowunlock ret=0x0 */
>  5)   2.931 us    |  } /* mutex_unlock ret=0x0 */
> 
> Signed-off-by: Changbin Du <changbin.du@huawei.com>
> ---
>  tools/perf/Documentation/perf-ftrace.txt |  4 ++
>  tools/perf/builtin-ftrace.c              | 60 +++++++++++++++++++++++-
>  tools/perf/util/ftrace.h                 |  4 ++
>  3 files changed, 67 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
> index b77f58c4d2fd..4b21a755132f 100644
> --- a/tools/perf/Documentation/perf-ftrace.txt
> +++ b/tools/perf/Documentation/perf-ftrace.txt
> @@ -123,6 +123,10 @@ OPTIONS for 'perf ftrace trace'
>  --graph-opts::
>  	List of options allowed to set:
>  
> +	  - args         - Show function arguments.
> +	  - retval       - Show function return value.
> +	  - retval-hex   - Show function return value in hexadecimal format.
> +	  - retaddr      - Show function return address.
>  	  - nosleep-time - Measure on-CPU time only for function_graph tracer.
>  	  - noirqs       - Ignore functions that happen inside interrupt.
>  	  - verbose      - Show process names, PIDs, timestamps, etc.
> diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
> index bba36ebc2aa7..f7cf1dd7b64b 100644
> --- a/tools/perf/builtin-ftrace.c
> +++ b/tools/perf/builtin-ftrace.c
> @@ -301,6 +301,10 @@ static void reset_tracing_options(struct perf_ftrace *ftrace __maybe_unused)
>  	write_tracing_option_file("funcgraph-proc", "0");
>  	write_tracing_option_file("funcgraph-abstime", "0");
>  	write_tracing_option_file("funcgraph-tail", "0");
> +	write_tracing_option_file("funcgraph-args", "0");
> +	write_tracing_option_file("funcgraph-retval", "0");
> +	write_tracing_option_file("funcgraph-retval-hex", "0");
> +	write_tracing_option_file("funcgraph-retaddr", "0");
>  	write_tracing_option_file("latency-format", "0");
>  	write_tracing_option_file("irq-info", "0");
>  }
> @@ -542,6 +546,41 @@ static int set_tracing_sleep_time(struct perf_ftrace *ftrace)
>  	return 0;
>  }
>  
> +static int set_tracing_funcgraph_args(struct perf_ftrace *ftrace)
> +{
> +	if (ftrace->graph_args) {
> +		if (write_tracing_option_file("funcgraph-args", "1") < 0)
> +			return -1;
> +	}
> +
> +	return 0;
> +}
> +
> +static int set_tracing_funcgraph_retval(struct perf_ftrace *ftrace)
> +{
> +	if (ftrace->graph_retval || ftrace->graph_retval_hex) {
> +		if (write_tracing_option_file("funcgraph-retval", "1") < 0)
> +			return -1;
> +	}
> +
> +	if (ftrace->graph_retval_hex) {
> +		if (write_tracing_option_file("funcgraph-retval-hex", "1") < 0)
> +			return -1;
> +	}
> +
> +	return 0;
> +}
> +
> +static int set_tracing_funcgraph_retaddr(struct perf_ftrace *ftrace)
> +{
> +	if (ftrace->graph_retaddr) {
> +		if (write_tracing_option_file("funcgraph-retaddr", "1") < 0)
> +			return -1;
> +	}
> +
> +	return 0;
> +}
> +
>  static int set_tracing_funcgraph_irqs(struct perf_ftrace *ftrace)
>  {
>  	if (!ftrace->graph_noirqs)
> @@ -642,6 +681,21 @@ static int set_tracing_options(struct perf_ftrace *ftrace)
>  		return -1;
>  	}
>  
> +	if (set_tracing_funcgraph_args(ftrace) < 0) {
> +		pr_err("failed to set tracing option funcgraph-args\n");
> +		return -1;
> +	}
> +
> +	if (set_tracing_funcgraph_retval(ftrace) < 0) {
> +		pr_err("failed to set tracing option funcgraph-retval\n");
> +		return -1;
> +	}
> +
> +	if (set_tracing_funcgraph_retaddr(ftrace) < 0) {
> +		pr_err("failed to set tracing option funcgraph-retaddr\n");
> +		return -1;
> +	}
> +
>  	if (set_tracing_funcgraph_irqs(ftrace) < 0) {
>  		pr_err("failed to set tracing option funcgraph-irqs\n");
>  		return -1;
> @@ -1607,6 +1661,10 @@ static int parse_graph_tracer_opts(const struct option *opt,
>  	int ret;
>  	struct perf_ftrace *ftrace = (struct perf_ftrace *) opt->value;
>  	struct sublevel_option graph_tracer_opts[] = {
> +		{ .name = "args",		.value_ptr = &ftrace->graph_args },
> +		{ .name = "retval",		.value_ptr = &ftrace->graph_retval },
> +		{ .name = "retval-hex",		.value_ptr = &ftrace->graph_retval_hex },
> +		{ .name = "retaddr",		.value_ptr = &ftrace->graph_retaddr },
>  		{ .name = "nosleep-time",	.value_ptr = &ftrace->graph_nosleep_time },
>  		{ .name = "noirqs",		.value_ptr = &ftrace->graph_noirqs },
>  		{ .name = "verbose",		.value_ptr = &ftrace->graph_verbose },
> @@ -1699,7 +1757,7 @@ int cmd_ftrace(int argc, const char **argv)
>  	OPT_CALLBACK('g', "nograph-funcs", &ftrace.nograph_funcs, "func",
>  		     "Set nograph filter on given functions", parse_filter_func),
>  	OPT_CALLBACK(0, "graph-opts", &ftrace, "options",
> -		     "Graph tracer options, available options: nosleep-time,noirqs,verbose,thresh=<n>,depth=<n>",
> +		     "Graph tracer options, available options: args,retval,retval-hex,retaddr,nosleep-time,noirqs,verbose,thresh=<n>,depth=<n>",
>  		     parse_graph_tracer_opts),
>  	OPT_CALLBACK('m', "buffer-size", &ftrace.percpu_buffer_size, "size",
>  		     "Size of per cpu buffer, needs to use a B, K, M or G suffix.", parse_buffer_size),
> diff --git a/tools/perf/util/ftrace.h b/tools/perf/util/ftrace.h
> index a9bc47da83a5..782c33227e92 100644
> --- a/tools/perf/util/ftrace.h
> +++ b/tools/perf/util/ftrace.h
> @@ -29,6 +29,10 @@ struct perf_ftrace {
>  	int			graph_depth;
>  	int			func_stack_trace;
>  	int			func_irq_info;
> +	int			graph_args;
> +	int			graph_retval;
> +	int			graph_retval_hex;
> +	int			graph_retaddr;
>  	int			graph_nosleep_time;
>  	int			graph_noirqs;
>  	int			graph_verbose;
> -- 
> 2.43.0
> 

-- 
Cheers,
Changbin Du