[PATCH v2 0/6] use canonical ftrace path whenever possible

[PATCH v2 0/6] use canonical ftrace path whenever possible

[Ross Zwisler]

Changes in v2:
 * Dropped patches which were pulled into maintainer trees.
 * Split BPF patches out into another series targeting bpf-next.
 * trace-agent now falls back to debugfs if tracefs isn't present.
 * Added Acked-by from mst@redhat.com to series.
 * Added a typo fixup for the virtio-trace README.

Steven, assuming there are no objections, would you feel comfortable
taking this series through your tree?

---
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

There are many places where this older debugfs path is still used in
code comments, selftests, examples and tools, so let's update them to
avoid confusion.

I've broken up the series as best I could by maintainer or directory,
and I've only sent people the patches that I think they care about to
avoid spamming everyone.

Ross Zwisler (6):
  tracing: always use canonical ftrace path
  selftests: use canonical ftrace path
  leaking_addresses: also skip canonical ftrace path
  tools/kvm_stat: use canonical ftrace path
  tools/virtio: use canonical ftrace path
  tools/virtio: fix typo in README instructions

 include/linux/kernel.h                        |  2 +-
 include/linux/tracepoint.h                    |  4 ++--
 kernel/trace/Kconfig                          | 20 +++++++++----------
 kernel/trace/kprobe_event_gen_test.c          |  2 +-
 kernel/trace/ring_buffer.c                    |  2 +-
 kernel/trace/synth_event_gen_test.c           |  2 +-
 kernel/trace/trace.c                          |  2 +-
 samples/user_events/example.c                 |  4 ++--
 scripts/leaking_addresses.pl                  |  1 +
 scripts/tracing/draw_functrace.py             |  6 +++---
 tools/kvm/kvm_stat/kvm_stat                   |  2 +-
 tools/lib/api/fs/tracing_path.c               |  4 ++--
 .../testing/selftests/user_events/dyn_test.c  |  2 +-
 .../selftests/user_events/ftrace_test.c       | 10 +++++-----
 .../testing/selftests/user_events/perf_test.c |  8 ++++----
 tools/testing/selftests/vm/protection_keys.c  |  4 ++--
 tools/tracing/latency/latency-collector.c     |  2 +-
 tools/virtio/virtio-trace/README              |  4 ++--
 tools/virtio/virtio-trace/trace-agent.c       | 12 +++++++----
 19 files changed, 49 insertions(+), 44 deletions(-)

-- 
2.39.1.637.g21b0678d19-goog

[PATCH v2 4/6] tools/kvm_stat: use canonical ftrace path

[Ross Zwisler]

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 comment in kvm_stat still refers to this older debugfs path, so let's
update it to avoid confusion.

Signed-off-by: Ross Zwisler <zwisler@google.com>
---
 tools/kvm/kvm_stat/kvm_stat | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/kvm/kvm_stat/kvm_stat b/tools/kvm/kvm_stat/kvm_stat
index 6f28180ffeea..15bf00e79e3f 100755
--- a/tools/kvm/kvm_stat/kvm_stat
+++ b/tools/kvm/kvm_stat/kvm_stat
@@ -627,7 +627,7 @@ class TracepointProvider(Provider):
         name)'.
 
         All available events have directories under
-        /sys/kernel/debug/tracing/events/ which export information
+        /sys/kernel/tracing/events/ which export information
         about the specific event. Therefore, listing the dirs gives us
         a list of all available events.
 
-- 
2.39.1.637.g21b0678d19-goog

Re: [PATCH v2 4/6] tools/kvm_stat: use canonical ftrace path

[Steven Rostedt]

On Wed, 15 Feb 2023 15:33:48 -0700
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 comment in kvm_stat still refers to this older debugfs path, so let's
> update it to avoid confusion.
> 
> Signed-off-by: Ross Zwisler <zwisler@google.com>

Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>

-- Steve

Re: [PATCH v2 4/6] tools/kvm_stat: use canonical ftrace path

[Paolo Bonzini]

On 2/15/23 23:33, Ross Zwisler 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 comment in kvm_stat still refers to this older debugfs path, so let's
> update it to avoid confusion.
> 
> Signed-off-by: Ross Zwisler <zwisler@google.com>
> ---
>   tools/kvm/kvm_stat/kvm_stat | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/kvm/kvm_stat/kvm_stat b/tools/kvm/kvm_stat/kvm_stat
> index 6f28180ffeea..15bf00e79e3f 100755
> --- a/tools/kvm/kvm_stat/kvm_stat
> +++ b/tools/kvm/kvm_stat/kvm_stat
> @@ -627,7 +627,7 @@ class TracepointProvider(Provider):
>           name)'.
>   
>           All available events have directories under
> -        /sys/kernel/debug/tracing/events/ which export information
> +        /sys/kernel/tracing/events/ which export information
>           about the specific event. Therefore, listing the dirs gives us
>           a list of all available events.
>   

Acked-by: Paolo Bonzini <pbonzini@redhat.com>

Re: [PATCH v2 4/6] tools/kvm_stat: use canonical ftrace path

[Mukesh Ojha]

On 2/16/2023 4:03 AM, Ross Zwisler 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 comment in kvm_stat still refers to this older debugfs path, so let's
> update it to avoid confusion.
> 
> Signed-off-by: Ross Zwisler <zwisler@google.com>
> ---
>   tools/kvm/kvm_stat/kvm_stat | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/kvm/kvm_stat/kvm_stat b/tools/kvm/kvm_stat/kvm_stat
> index 6f28180ffeea..15bf00e79e3f 100755
> --- a/tools/kvm/kvm_stat/kvm_stat
> +++ b/tools/kvm/kvm_stat/kvm_stat
> @@ -627,7 +627,7 @@ class TracepointProvider(Provider):
>           name)'.
>   
>           All available events have directories under
> -        /sys/kernel/debug/tracing/events/ which export information
> +        /sys/kernel/tracing/events/ which export information
>           about the specific event. Therefore, listing the dirs gives us
>           a list of all available events.
>   

Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>

-Mukesh

Re: [PATCH v2 0/6] use canonical ftrace path whenever possible

[Michael S. Tsirkin]

On Wed, Feb 15, 2023 at 03:33:44PM -0700, Ross Zwisler wrote:
> Changes in v2:
>  * Dropped patches which were pulled into maintainer trees.
>  * Split BPF patches out into another series targeting bpf-next.
>  * trace-agent now falls back to debugfs if tracefs isn't present.
>  * Added Acked-by from mst@redhat.com to series.
>  * Added a typo fixup for the virtio-trace README.
> 
> Steven, assuming there are no objections, would you feel comfortable
> taking this series through your tree?

Acked-by: Michael S. Tsirkin <mst@redhat.com>

if you want the virtio patches through my tree after all, let me know.

> ---
> 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
> 
> There are many places where this older debugfs path is still used in
> code comments, selftests, examples and tools, so let's update them to
> avoid confusion.
> 
> I've broken up the series as best I could by maintainer or directory,
> and I've only sent people the patches that I think they care about to
> avoid spamming everyone.
> 
> Ross Zwisler (6):
>   tracing: always use canonical ftrace path
>   selftests: use canonical ftrace path
>   leaking_addresses: also skip canonical ftrace path
>   tools/kvm_stat: use canonical ftrace path
>   tools/virtio: use canonical ftrace path
>   tools/virtio: fix typo in README instructions
> 
>  include/linux/kernel.h                        |  2 +-
>  include/linux/tracepoint.h                    |  4 ++--
>  kernel/trace/Kconfig                          | 20 +++++++++----------
>  kernel/trace/kprobe_event_gen_test.c          |  2 +-
>  kernel/trace/ring_buffer.c                    |  2 +-
>  kernel/trace/synth_event_gen_test.c           |  2 +-
>  kernel/trace/trace.c                          |  2 +-
>  samples/user_events/example.c                 |  4 ++--
>  scripts/leaking_addresses.pl                  |  1 +
>  scripts/tracing/draw_functrace.py             |  6 +++---
>  tools/kvm/kvm_stat/kvm_stat                   |  2 +-
>  tools/lib/api/fs/tracing_path.c               |  4 ++--
>  .../testing/selftests/user_events/dyn_test.c  |  2 +-
>  .../selftests/user_events/ftrace_test.c       | 10 +++++-----
>  .../testing/selftests/user_events/perf_test.c |  8 ++++----
>  tools/testing/selftests/vm/protection_keys.c  |  4 ++--
>  tools/tracing/latency/latency-collector.c     |  2 +-
>  tools/virtio/virtio-trace/README              |  4 ++--
>  tools/virtio/virtio-trace/trace-agent.c       | 12 +++++++----
>  19 files changed, 49 insertions(+), 44 deletions(-)
> 
> -- 
> 2.39.1.637.g21b0678d19-goog

Re: [PATCH v2 0/6] use canonical ftrace path whenever possible

[Ross Zwisler]

On Fri, Mar 10, 2023 at 03:29:49AM -0500, Michael S. Tsirkin wrote:
> On Wed, Feb 15, 2023 at 03:33:44PM -0700, Ross Zwisler wrote:
> > Changes in v2:
> >  * Dropped patches which were pulled into maintainer trees.
> >  * Split BPF patches out into another series targeting bpf-next.
> >  * trace-agent now falls back to debugfs if tracefs isn't present.
> >  * Added Acked-by from mst@redhat.com to series.
> >  * Added a typo fixup for the virtio-trace README.
> > 
> > Steven, assuming there are no objections, would you feel comfortable
> > taking this series through your tree?
> 
> Acked-by: Michael S. Tsirkin <mst@redhat.com>
> 
> if you want the virtio patches through my tree after all, let me know.

Yes, please, that would be great.  I'll send out v3 with the few patches that
haven't gotten a response, but I'll drop the virtio patches assuming you've
got them.

Thanks!

Re: [PATCH v2 0/6] use canonical ftrace path whenever possible

[Steven Rostedt]

On Fri, 10 Mar 2023 12:06:58 -0700
Ross Zwisler <zwisler@google.com> wrote:

> On Fri, Mar 10, 2023 at 03:29:49AM -0500, Michael S. Tsirkin wrote:
> > On Wed, Feb 15, 2023 at 03:33:44PM -0700, Ross Zwisler wrote:  
> > > Changes in v2:
> > >  * Dropped patches which were pulled into maintainer trees.
> > >  * Split BPF patches out into another series targeting bpf-next.
> > >  * trace-agent now falls back to debugfs if tracefs isn't present.
> > >  * Added Acked-by from mst@redhat.com to series.
> > >  * Added a typo fixup for the virtio-trace README.
> > > 
> > > Steven, assuming there are no objections, would you feel comfortable
> > > taking this series through your tree?  
> > 
> > Acked-by: Michael S. Tsirkin <mst@redhat.com>
> > 
> > if you want the virtio patches through my tree after all, let me know.  
> 
> Yes, please, that would be great.  I'll send out v3 with the few patches that
> haven't gotten a response, but I'll drop the virtio patches assuming you've
> got them.
>

Since the last patch 6/6 is not tracing related, I would prefer it to go
through the virtio tree.

For patches 1-5, please add:

Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Thanks!

-- Steve

Re: [PATCH v2 0/6] use canonical ftrace path whenever possible

[Michael S. Tsirkin]

On Wed, Feb 15, 2023 at 03:33:44PM -0700, Ross Zwisler wrote:
> Changes in v2:
>  * Dropped patches which were pulled into maintainer trees.
>  * Split BPF patches out into another series targeting bpf-next.
>  * trace-agent now falls back to debugfs if tracefs isn't present.
>  * Added Acked-by from mst@redhat.com to series.
>  * Added a typo fixup for the virtio-trace README.
> 
> Steven, assuming there are no objections, would you feel comfortable
> taking this series through your tree?

for merging up to patch 5 through another tree:

Acked-by: Michael S. Tsirkin <mst@redhat.com>

I'll merge patch 6, no problem.


> ---
> 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
> 
> There are many places where this older debugfs path is still used in
> code comments, selftests, examples and tools, so let's update them to
> avoid confusion.
> 
> I've broken up the series as best I could by maintainer or directory,
> and I've only sent people the patches that I think they care about to
> avoid spamming everyone.
> 
> Ross Zwisler (6):
>   tracing: always use canonical ftrace path
>   selftests: use canonical ftrace path
>   leaking_addresses: also skip canonical ftrace path
>   tools/kvm_stat: use canonical ftrace path
>   tools/virtio: use canonical ftrace path
>   tools/virtio: fix typo in README instructions
> 
>  include/linux/kernel.h                        |  2 +-
>  include/linux/tracepoint.h                    |  4 ++--
>  kernel/trace/Kconfig                          | 20 +++++++++----------
>  kernel/trace/kprobe_event_gen_test.c          |  2 +-
>  kernel/trace/ring_buffer.c                    |  2 +-
>  kernel/trace/synth_event_gen_test.c           |  2 +-
>  kernel/trace/trace.c                          |  2 +-
>  samples/user_events/example.c                 |  4 ++--
>  scripts/leaking_addresses.pl                  |  1 +
>  scripts/tracing/draw_functrace.py             |  6 +++---
>  tools/kvm/kvm_stat/kvm_stat                   |  2 +-
>  tools/lib/api/fs/tracing_path.c               |  4 ++--
>  .../testing/selftests/user_events/dyn_test.c  |  2 +-
>  .../selftests/user_events/ftrace_test.c       | 10 +++++-----
>  .../testing/selftests/user_events/perf_test.c |  8 ++++----
>  tools/testing/selftests/vm/protection_keys.c  |  4 ++--
>  tools/tracing/latency/latency-collector.c     |  2 +-
>  tools/virtio/virtio-trace/README              |  4 ++--
>  tools/virtio/virtio-trace/trace-agent.c       | 12 +++++++----
>  19 files changed, 49 insertions(+), 44 deletions(-)
> 
> -- 
> 2.39.1.637.g21b0678d19-goog

Re: [PATCH v2 0/6] use canonical ftrace path whenever possible

[Ross Zwisler]

On Tue, Mar 21, 2023 at 10:32:46PM -0400, Michael S. Tsirkin wrote:
> On Wed, Feb 15, 2023 at 03:33:44PM -0700, Ross Zwisler wrote:
> > Changes in v2:
> >  * Dropped patches which were pulled into maintainer trees.
> >  * Split BPF patches out into another series targeting bpf-next.
> >  * trace-agent now falls back to debugfs if tracefs isn't present.
> >  * Added Acked-by from mst@redhat.com to series.
> >  * Added a typo fixup for the virtio-trace README.
> > 
> > Steven, assuming there are no objections, would you feel comfortable
> > taking this series through your tree?
> 
> for merging up to patch 5 through another tree:
> 
> Acked-by: Michael S. Tsirkin <mst@redhat.com>
> 
> I'll merge patch 6, no problem.

Hey Michael, would you also mind merging patch 5, the other virtio patch?

[PATCH v2 5/6] tools/virtio: use canonical ftrace path

https://lore.kernel.org/all/20230215223350.2658616-6-zwisler@google.com/

I don't think Steven took this one through his tree.  Thanks!