On 7/17/24 11:50 AM, Steven Rostedt wrote:
> On Tue, 21 May 2024 14:37:30 -0700
> Jianfeng Wang <jianfeng.w.wang@xxxxxxxxxx> wrote:
>
>> Add two internal options for fgraph: fgraph:retval-skip and
>> fgraph:retval-hex. By default, trace-cmd will print each function's
>> return value at the function_graph exit point, if the kernel supports
>> the fgraph-retval feature. If users want to skip the output of
>> functions' return values, then set fgraph:retval-skip. Alternatively,
>> users can set fgraph:retval-hex to force the return values to be
>> printed in hex format.
>>
>> Here are example commands:
>>> trace-cmd report -O fgraph:retval-skip
>>> trace-cmd report -O fgraph:retval-hex
>
> I would like to see a -O fgraph:retval-dec
>
> As by default most is shown in hex, having an option to do that would
> be great.
>
> -- Steve
>
>
Hi Steve,
Sorry, I am confused about this.
Do you suggesting adding one more option fgraph:retval-dec or
replacing fgraph:retval-hex with fgraph:retval-dec (and making the hex
format as the default)?
Currently, the patch prints return values in decimal by default
(without any input), while users can specify fgraph:retval-hex to let
numbers printed in hex.
Thanks for your comments.
Best,
-Jianfeng
>>
>> Signed-off-by: Jianfeng Wang <jianfeng.w.wang@xxxxxxxxxx>
>> ---
>> lib/trace-cmd/trace-ftrace.c | 22 ++++++++++++++++++----
>> 1 file changed, 18 insertions(+), 4 deletions(-)
>>
>> diff --git a/lib/trace-cmd/trace-ftrace.c b/lib/trace-cmd/trace-ftrace.c
>> index 2b4e49a5..d2378833 100644
>> --- a/lib/trace-cmd/trace-ftrace.c
>> +++ b/lib/trace-cmd/trace-ftrace.c
>> @@ -26,6 +26,18 @@ struct tep_plugin_option trace_ftrace_options[] = {
>> .description =
>> "Show the depth of each entry",
>> },
>> + {
>> + .name = "retval-skip",
>> + .plugin_alias = "fgraph",
>> + .description =
>> + "Skip printing function retval in function graph",
>> + },
>> + {
>> + .name = "retval-hex",
>> + .plugin_alias = "fgraph",
>> + .description =
>> + "Print function retval in hex at function exit in function graph",
>> + },
>> {
>> .name = NULL,
>> }
>> @@ -33,6 +45,8 @@ struct tep_plugin_option trace_ftrace_options[] = {
>>
>> static struct tep_plugin_option *fgraph_tail = &trace_ftrace_options[0];
>> static struct tep_plugin_option *fgraph_depth = &trace_ftrace_options[1];
>> +static struct tep_plugin_option *fgraph_retval_skip = &trace_ftrace_options[2];
>> +static struct tep_plugin_option *fgraph_retval_hex = &trace_ftrace_options[3];
>>
>> static int find_ret_event(struct tracecmd_ftrace *finfo, struct tep_handle *pevent)
>> {
>> @@ -235,8 +249,8 @@ print_graph_entry_leaf(struct trace_seq *s,
>> ret = trace_seq_printf(s, " (%lld)", depth);
>>
>> /* Return Value */
>> - if (ret && fgraph_retval_supported) {
>> - if (!IS_LINUX_ERR_VALUE(retval))
>> + if (ret && fgraph_retval_supported && !fgraph_retval_skip->set) {
>> + if (fgraph_retval_hex->set || !IS_LINUX_ERR_VALUE(retval))
>> ret = trace_seq_printf(s, " (ret=0x%llx)", retval);
>> else
>> ret = trace_seq_printf(s, " (ret=%lld)", retval);
>> @@ -385,8 +399,8 @@ fgraph_ret_handler(struct trace_seq *s, struct tep_record *record,
>> trace_seq_printf(s, " (%lld)", depth);
>>
>> /* Return Value */
>> - if (fgraph_retval_supported) {
>> - if (!IS_LINUX_ERR_VALUE(retval))
>> + if (fgraph_retval_supported && !fgraph_retval_skip->set) {
>> + if (fgraph_retval_hex->set || !IS_LINUX_ERR_VALUE(retval))
>> trace_seq_printf(s, " (ret=0x%llx)", retval);
>> else
>> trace_seq_printf(s, " (ret=%lld)", retval);
>
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