1. Patchew
  2. linux
  3. [PATCH 0/9] use canonical ftrace path whenever possible
  4. View patch

[PATCH 5/9] tools/power: use canonical ftrace path

Ross Zwisler posted 9 patches 3 years ago
There is a newer version of this series
[PATCH 5/9] tools/power: use canonical ftrace path
Posted by Ross Zwisler 3 years ago 
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>
---
 tools/power/pm-graph/sleepgraph.py                     |  4 ++--
 tools/power/x86/amd_pstate_tracer/amd_pstate_trace.py  |  4 ++--
 .../x86/intel_pstate_tracer/intel_pstate_tracer.py     | 10 +++++-----
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/tools/power/pm-graph/sleepgraph.py b/tools/power/pm-graph/sleepgraph.py
index cfe343306e08..eddf8101ddf6 100755
--- a/tools/power/pm-graph/sleepgraph.py
+++ b/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'
diff --git a/tools/power/x86/amd_pstate_tracer/amd_pstate_trace.py b/tools/power/x86/amd_pstate_tracer/amd_pstate_trace.py
index 2dea4032ac56..904df0ea0a1e 100755
--- a/tools/power/x86/amd_pstate_tracer/amd_pstate_trace.py
+++ b/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 @@ print(cur_version)
 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)
diff --git a/tools/power/x86/intel_pstate_tracer/intel_pstate_tracer.py b/tools/power/x86/intel_pstate_tracer/intel_pstate_tracer.py
index b46e9eb8f5aa..ec3323100e1a 100755
--- a/tools/power/x86/intel_pstate_tracer/intel_pstate_tracer.py
+++ b/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 @@ if __name__ == "__main__":
     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)
-- 
2.39.1.456.gfc5497dd1b-goog
Re: [PATCH 5/9] tools/power: use canonical ftrace path
Posted by Rafael J. Wysocki 3 years ago 
On Mon, Jan 30, 2023 at 7:20 PM Ross Zwisler <zwisler@chromium.org> wrote:
>
> 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>
> ---
>  tools/power/pm-graph/sleepgraph.py                     |  4 ++--
>  tools/power/x86/amd_pstate_tracer/amd_pstate_trace.py  |  4 ++--
>  .../x86/intel_pstate_tracer/intel_pstate_tracer.py     | 10 +++++-----
>  3 files changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/tools/power/pm-graph/sleepgraph.py b/tools/power/pm-graph/sleepgraph.py
> index cfe343306e08..eddf8101ddf6 100755
> --- a/tools/power/pm-graph/sleepgraph.py
> +++ b/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'
> diff --git a/tools/power/x86/amd_pstate_tracer/amd_pstate_trace.py b/tools/power/x86/amd_pstate_tracer/amd_pstate_trace.py
> index 2dea4032ac56..904df0ea0a1e 100755
> --- a/tools/power/x86/amd_pstate_tracer/amd_pstate_trace.py
> +++ b/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 @@ print(cur_version)
>  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)
> diff --git a/tools/power/x86/intel_pstate_tracer/intel_pstate_tracer.py b/tools/power/x86/intel_pstate_tracer/intel_pstate_tracer.py
> index b46e9eb8f5aa..ec3323100e1a 100755
> --- a/tools/power/x86/intel_pstate_tracer/intel_pstate_tracer.py
> +++ b/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 @@ if __name__ == "__main__":
>      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)
> --

Applied as 6.3 material, thanks!

Patchew 2.1-devel-b67e4c2

© 2016 - 2026 Red Hat, Inc.