PM: tools: use canonical ftrace path

The canonical location for the tracefs filesystem is at /sys/kernel/tracing.

But, from Documentation/trace/ftrace.rst:

  Before 4.1, all ftrace tracing control files were within the debugfs
  file system, which is typically located at /sys/kernel/debug/tracing.
  For backward compatibility, when mounting the debugfs file system,
  the tracefs file system will be automatically mounted at:

  /sys/kernel/debug/tracing

A few scripts in tools/power still refer to this older debugfs path, so
let's update them to avoid confusion.

Signed-off-by: Ross Zwisler <zwisler@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: Ross Zwisler

tools/power/pm-graph/sleepgraph.py

@@ -120,9 +120,9 @@ class SystemValues:
 	cgexp = False
 	testdir = ''
 	outdir = ''
-	tpath = '/sys/kernel/debug/tracing/'
+	tpath = '/sys/kernel/tracing/'
 	fpdtpath = '/sys/firmware/acpi/tables/FPDT'
-	epath = '/sys/kernel/debug/tracing/events/power/'
+	epath = '/sys/kernel/tracing/events/power/'
 	pmdpath = '/sys/power/pm_debug_messages'
 	s0ixpath = '/sys/module/intel_pmc_core/parameters/warn_on_s0ix_failures'
 	s0ixres = '/sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us'

tools/power/x86/amd_pstate_tracer/amd_pstate_trace.py

@@ -248,7 +248,7 @@ def signal_handler(signal, frame):
         ipt.free_trace_buffer()
         sys.exit(0)
 
-trace_file = "/sys/kernel/debug/tracing/events/amd_cpu/enable"
+trace_file = "/sys/kernel/tracing/events/amd_cpu/enable"
 signal.signal(signal.SIGINT, signal_handler)
 
 interval = ""
@@ -319,7 +319,7 @@ def signal_handler(signal, frame):
 cleanup_data_files()
 
 if interval:
-    file_name = "/sys/kernel/debug/tracing/trace"
+    file_name = "/sys/kernel/tracing/trace"
     ipt.clear_trace_file()
     ipt.set_trace_buffer_size(memory)
     ipt.enable_trace(trace_file)

tools/power/x86/intel_pstate_tracer/intel_pstate_tracer.py

@@ -373,7 +373,7 @@ def clear_trace_file():
     """ Clear trace file """
 
     try:
-        f_handle = open('/sys/kernel/debug/tracing/trace', 'w')
+        f_handle = open('/sys/kernel/tracing/trace', 'w')
         f_handle.close()
     except:
         print('IO error clearing trace file ')
@@ -401,7 +401,7 @@ def set_trace_buffer_size(memory):
     """ Set trace buffer size """
 
     try:
-       with open('/sys/kernel/debug/tracing/buffer_size_kb', 'w') as fp:
+       with open('/sys/kernel/tracing/buffer_size_kb', 'w') as fp:
           fp.write(memory)
     except:
        print('IO error setting trace buffer size ')
@@ -411,7 +411,7 @@ def free_trace_buffer():
     """ Free the trace buffer memory """
 
     try:
-       open('/sys/kernel/debug/tracing/buffer_size_kb'
+       open('/sys/kernel/tracing/buffer_size_kb'
                  , 'w').write("1")
     except:
         print('IO error freeing trace buffer ')
@@ -495,7 +495,7 @@ def signal_handler(signal, frame):
         sys.exit(0)
 
 if __name__ == "__main__":
-    trace_file = "/sys/kernel/debug/tracing/events/power/pstate_sample/enable"
+    trace_file = "/sys/kernel/tracing/events/power/pstate_sample/enable"
     signal.signal(signal.SIGINT, signal_handler)
 
     interval = ""
@@ -569,7 +569,7 @@ def signal_handler(signal, frame):
     cleanup_data_files()
 
     if interval:
-        filename = "/sys/kernel/debug/tracing/trace"
+        filename = "/sys/kernel/tracing/trace"
         clear_trace_file()
         set_trace_buffer_size(memory)
         enable_trace(trace_file)