perf ftrace: Add 'profile' command

The 'perf ftrace profile' command is to get function execution profiles
using function-graph tracer so that users can see the total, average,
max execution time as well as the number of invocations easily.

The following is a profile for the perf_event_open syscall.

  $ sudo perf ftrace profile -G __x64_sys_perf_event_open -- \
    perf stat -e cycles -C1 true 2> /dev/null | head
  # Total (us)   Avg (us)   Max (us)      Count   Function
        65.611     65.611     65.611          1   __x64_sys_perf_event_open
        30.527     30.527     30.527          1   anon_inode_getfile
        30.260     30.260     30.260          1   __anon_inode_getfile
        29.700     29.700     29.700          1   alloc_file_pseudo
        17.578     17.578     17.578          1   d_alloc_pseudo
        17.382     17.382     17.382          1   __d_alloc
        16.738     16.738     16.738          1   kmem_cache_alloc_lru
        15.686     15.686     15.686          1   perf_event_alloc
        14.012      7.006     11.264          2   obj_cgroup_charge
  #

Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Changbin Du <changbin.du@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/lkml/20240729004127.238611-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-ftrace.txt

@@ -9,7 +9,7 @@ perf-ftrace - simple wrapper for kernel's ftrace functionality
 SYNOPSIS
 --------
 [verse]
-'perf ftrace' {trace|latency} <command>
+'perf ftrace' {trace|latency|profile} <command>
 
 DESCRIPTION
 -----------
@@ -23,6 +23,9 @@ kernel's ftrace infrastructure.
   'perf ftrace latency' calculates execution latency of a given function
   (optionally with BPF) and display it as a histogram.
 
+  'perf ftrace profile' show a execution profile for each function including
+  total, average, max time and the number of calls.
+
 The following options apply to perf ftrace.
 
 COMMON OPTIONS
@@ -146,6 +149,43 @@ OPTIONS for 'perf ftrace latency'
 	Use nano-second instead of micro-second as a base unit of the histogram.
 
 
+OPTIONS for 'perf ftrace profile'
+---------------------------------
+
+-T::
+--trace-funcs=::
+	Set function filter on the given function (or a glob pattern).
+	Multiple functions can be given by using this option more than once.
+	The function argument also can be a glob pattern. It will be passed
+	to 'set_ftrace_filter' in tracefs.
+
+-N::
+--notrace-funcs=::
+	Do not trace functions given by the argument.  Like -T option, this
+	can be used more than once to specify multiple functions (or glob
+	patterns).  It will be passed to 'set_ftrace_notrace' in tracefs.
+
+-G::
+--graph-funcs=::
+	Set graph filter on the given function (or a glob pattern). This is
+	useful to trace for functions executed from the given function. This
+	can be used more than once to specify multiple functions. It will be
+	passed to 'set_graph_function' in tracefs.
+
+-g::
+--nograph-funcs=::
+	Set graph notrace filter on the given function (or a glob pattern).
+	Like -G option, this is useful for the function_graph tracer only and
+	disables tracing for function executed from the given function. This
+	can be used more than once to specify multiple functions. It will be
+	passed to 'set_graph_notrace' in tracefs.
+
+-m::
+--buffer-size::
+	Set the size of per-cpu tracing buffer, <size> is expected to
+	be a number with appended unit character - B/K/M/G.
+
+
 SEE ALSO
 --------
 linkperf:perf-record[1], linkperf:perf-trace[1]