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References: <20230130181915.1113313-1-zwisler@google.com> <20230130181915.1113313-6-zwisler@google.com>
In-Reply-To: <20230130181915.1113313-6-zwisler@google.com>
From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Thu, 2 Feb 2023 15:47:24 +0100
Message-ID: <CAJZ5v0hSJGb59rYRN=uJq2-39Rz5pk2yV7jufrWgWMPO397hZw@mail.gmail.com>
Subject: Re: [PATCH 5/9] tools/power: use canonical ftrace path
To:     Ross Zwisler <zwisler@chromium.org>
Cc:     linux-kernel@vger.kernel.org, Ross Zwisler <zwisler@google.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        linux-trace-kernel@vger.kernel.org,
        Todd E Brandt <todd.e.brandt@linux.intel.com>,
        Huang Rui <ray.huang@amd.com>, linux-pm@vger.kernel.org
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Precedence: bulk

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!