[PATCH 7/9] tools/virtio: use canonical ftrace path

From: Ross Zwisler
Date: Mon Jan 30 2023 - 13:20:12 EST


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 spots in tools/virtio still refer to this older debugfs
path, so let's update them to avoid confusion.

Signed-off-by: Ross Zwisler <zwisler@xxxxxxxxxx>
---
tools/virtio/virtio-trace/README | 2 +-
tools/virtio/virtio-trace/trace-agent.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/virtio/virtio-trace/README b/tools/virtio/virtio-trace/README
index b64845b823ab..cea29a2a4c0a 100644
--- a/tools/virtio/virtio-trace/README
+++ b/tools/virtio/virtio-trace/README
@@ -95,7 +95,7 @@ Run

1) Enable ftrace in the guest
<Example>
- # echo 1 > /sys/kernel/debug/tracing/events/sched/enable
+ # echo 1 > /sys/kernel/tracing/events/sched/enable

2) Run trace agent in the guest
This agent must be operated as root.
diff --git a/tools/virtio/virtio-trace/trace-agent.c b/tools/virtio/virtio-trace/trace-agent.c
index cdfe77c2b4c8..805942d02e9f 100644
--- a/tools/virtio/virtio-trace/trace-agent.c
+++ b/tools/virtio/virtio-trace/trace-agent.c
@@ -19,7 +19,7 @@
#define PIPE_MIN_SIZE (PAGE_SIZE*PIPE_DEF_BUFS)
#define PIPE_MAX_SIZE (1024*1024)
#define READ_PATH_FMT \
- "/sys/kernel/debug/tracing/per_cpu/cpu%d/trace_pipe_raw"
+ "/sys/kernel/tracing/per_cpu/cpu%d/trace_pipe_raw"
#define WRITE_PATH_FMT "/dev/virtio-ports/trace-path-cpu%d"
#define CTL_PATH "/dev/virtio-ports/agent-ctl-path"

--
2.39.1.456.gfc5497dd1b-goog