[PATCH 1/9] tracing: always use canonical ftrace path
From: Ross Zwisler
Date: Mon Jan 30 2023 - 13:20:06 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
Many comments and Kconfig help messages in the tracing code still refer
to this older debugfs path, so let's update them to avoid confusion.
Signed-off-by: Ross Zwisler <zwisler@xxxxxxxxxx>
---
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/tracing/draw_functrace.py | 6 +++---
scripts/tracing/ftrace-bisect.sh | 4 ++--
tools/lib/api/fs/tracing_path.c | 4 ++--
tools/lib/traceevent/event-parse.c | 8 ++++----
tools/tracing/latency/latency-collector.c | 2 +-
13 files changed, 31 insertions(+), 31 deletions(-)
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index fe6efb24d151..40bce7495af8 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -297,7 +297,7 @@ bool mac_pton(const char *s, u8 *mac);
*
* Use tracing_on/tracing_off when you want to quickly turn on or off
* tracing. It simply enables or disables the recording of the trace events.
- * This also corresponds to the user space /sys/kernel/debug/tracing/tracing_on
+ * This also corresponds to the user space /sys/kernel/tracing/tracing_on
* file, which gives a means for the kernel and userspace to interact.
* Place a tracing_off() in the kernel where you want tracing to end.
* From user space, examine the trace, and then echo 1 > tracing_on
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 4b33b95eb8be..fa1004fcf810 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -471,7 +471,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
* * This is how the trace record is structured and will
* * be saved into the ring buffer. These are the fields
* * that will be exposed to user-space in
- * * /sys/kernel/debug/tracing/events/<*>/format.
+ * * /sys/kernel/tracing/events/<*>/format.
* *
* * The declared 'local variable' is called '__entry'
* *
@@ -531,7 +531,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p)
* tracepoint callback (this is used by programmatic plugins and
* can also by used by generic instrumentation like SystemTap), and
* it is also used to expose a structured trace record in
- * /sys/kernel/debug/tracing/events/.
+ * /sys/kernel/tracing/events/.
*
* A set of (un)registration functions can be passed to the variant
* TRACE_EVENT_FN to perform any (un)registration work.
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index e9e95c790b8e..4b85674935d7 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -232,7 +232,7 @@ config DYNAMIC_FTRACE
enabled, and the functions not enabled will not affect
performance of the system.
- See the files in /sys/kernel/debug/tracing:
+ See the files in /sys/kernel/tracing:
available_filter_functions
set_ftrace_filter
set_ftrace_notrace
@@ -292,7 +292,7 @@ config STACK_TRACER
select KALLSYMS
help
This special tracer records the maximum stack footprint of the
- kernel and displays it in /sys/kernel/debug/tracing/stack_trace.
+ kernel and displays it in /sys/kernel/tracing/stack_trace.
This tracer works by hooking into every function call that the
kernel executes, and keeping a maximum stack depth value and
@@ -332,7 +332,7 @@ config IRQSOFF_TRACER
disabled by default and can be runtime (re-)started
via:
- echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
+ echo 0 > /sys/kernel/tracing/tracing_max_latency
(Note that kernel size and overhead increase with this option
enabled. This option and the preempt-off timing option can be
@@ -356,7 +356,7 @@ config PREEMPT_TRACER
disabled by default and can be runtime (re-)started
via:
- echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
+ echo 0 > /sys/kernel/tracing/tracing_max_latency
(Note that kernel size and overhead increase with this option
enabled. This option and the irqs-off timing option can be
@@ -506,7 +506,7 @@ config TRACER_SNAPSHOT
Allow tracing users to take snapshot of the current buffer using the
ftrace interface, e.g.:
- echo 1 > /sys/kernel/debug/tracing/snapshot
+ echo 1 > /sys/kernel/tracing/snapshot
cat snapshot
config TRACER_SNAPSHOT_PER_CPU_SWAP
@@ -518,7 +518,7 @@ config TRACER_SNAPSHOT_PER_CPU_SWAP
full swap (all buffers). If this is set, then the following is
allowed:
- echo 1 > /sys/kernel/debug/tracing/per_cpu/cpu2/snapshot
+ echo 1 > /sys/kernel/tracing/per_cpu/cpu2/snapshot
After which, only the tracing buffer for CPU 2 was swapped with
the main tracing buffer, and the other CPU buffers remain the same.
@@ -565,7 +565,7 @@ config PROFILE_ANNOTATED_BRANCHES
This tracer profiles all likely and unlikely macros
in the kernel. It will display the results in:
- /sys/kernel/debug/tracing/trace_stat/branch_annotated
+ /sys/kernel/tracing/trace_stat/branch_annotated
Note: this will add a significant overhead; only turn this
on if you need to profile the system's use of these macros.
@@ -578,7 +578,7 @@ config PROFILE_ALL_BRANCHES
taken in the kernel is recorded whether it hit or miss.
The results will be displayed in:
- /sys/kernel/debug/tracing/trace_stat/branch_all
+ /sys/kernel/tracing/trace_stat/branch_all
This option also enables the likely/unlikely profiler.
@@ -629,8 +629,8 @@ config BLK_DEV_IO_TRACE
Tracing also is possible using the ftrace interface, e.g.:
echo 1 > /sys/block/sda/sda1/trace/enable
- echo blk > /sys/kernel/debug/tracing/current_tracer
- cat /sys/kernel/debug/tracing/trace_pipe
+ echo blk > /sys/kernel/tracing/current_tracer
+ cat /sys/kernel/tracing/trace_pipe
If unsure, say N.
diff --git a/kernel/trace/kprobe_event_gen_test.c b/kernel/trace/kprobe_event_gen_test.c
index c736487fc0e4..4850fdfe27f1 100644
--- a/kernel/trace/kprobe_event_gen_test.c
+++ b/kernel/trace/kprobe_event_gen_test.c
@@ -21,7 +21,7 @@
* Then:
*
* # insmod kernel/trace/kprobe_event_gen_test.ko
- * # cat /sys/kernel/debug/tracing/trace
+ * # cat /sys/kernel/tracing/trace
*
* You should see many instances of the "gen_kprobe_test" and
* "gen_kretprobe_test" events in the trace buffer.
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index b21bf14bae9b..c4ad4939d149 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2868,7 +2868,7 @@ rb_check_timestamp(struct ring_buffer_per_cpu *cpu_buffer,
sched_clock_stable() ? "" :
"If you just came from a suspend/resume,\n"
"please switch to the trace global clock:\n"
- " echo global > /sys/kernel/debug/tracing/trace_clock\n"
+ " echo global > /sys/kernel/tracing/trace_clock\n"
"or add trace_clock=global to the kernel command line\n");
}
diff --git a/kernel/trace/synth_event_gen_test.c b/kernel/trace/synth_event_gen_test.c
index 8d77526892f4..8dfe85499d4a 100644
--- a/kernel/trace/synth_event_gen_test.c
+++ b/kernel/trace/synth_event_gen_test.c
@@ -22,7 +22,7 @@
* Then:
*
* # insmod kernel/trace/synth_event_gen_test.ko
- * # cat /sys/kernel/debug/tracing/trace
+ * # cat /sys/kernel/tracing/trace
*
* You should see several events in the trace buffer -
* "create_synth_test", "empty_synth_test", and several instances of
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index a7fe0e115272..4a034b9c429d 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1143,7 +1143,7 @@ void tracing_snapshot_instance(struct trace_array *tr)
*
* Note, make sure to allocate the snapshot with either
* a tracing_snapshot_alloc(), or by doing it manually
- * with: echo 1 > /sys/kernel/debug/tracing/snapshot
+ * with: echo 1 > /sys/kernel/tracing/snapshot
*
* If the snapshot buffer is not allocated, it will stop tracing.
* Basically making a permanent snapshot.
diff --git a/samples/user_events/example.c b/samples/user_events/example.c
index d06dc24156ec..18e34c9d708e 100644
--- a/samples/user_events/example.c
+++ b/samples/user_events/example.c
@@ -23,8 +23,8 @@
#endif
/* Assumes debugfs is mounted */
-const char *data_file = "/sys/kernel/debug/tracing/user_events_data";
-const char *status_file = "/sys/kernel/debug/tracing/user_events_status";
+const char *data_file = "/sys/kernel/tracing/user_events_data";
+const char *status_file = "/sys/kernel/tracing/user_events_status";
static int event_status(long **status)
{
diff --git a/scripts/tracing/draw_functrace.py b/scripts/tracing/draw_functrace.py
index 438516bdfb3c..42fa87300941 100755
--- a/scripts/tracing/draw_functrace.py
+++ b/scripts/tracing/draw_functrace.py
@@ -12,9 +12,9 @@ calls. Only the functions's names and the call time are provided.
Usage:
Be sure that you have CONFIG_FUNCTION_TRACER
- # mount -t debugfs nodev /sys/kernel/debug
- # echo function > /sys/kernel/debug/tracing/current_tracer
- $ cat /sys/kernel/debug/tracing/trace_pipe > ~/raw_trace_func
+ # mount -t tracefs nodev /sys/kernel/tracing
+ # echo function > /sys/kernel/tracing/current_tracer
+ $ cat /sys/kernel/tracing/trace_pipe > ~/raw_trace_func
Wait some times but not too much, the script is a bit slow.
Break the pipe (Ctrl + Z)
$ scripts/tracing/draw_functrace.py < ~/raw_trace_func > draw_functrace
diff --git a/scripts/tracing/ftrace-bisect.sh b/scripts/tracing/ftrace-bisect.sh
index 926701162bc8..53244096489e 100755
--- a/scripts/tracing/ftrace-bisect.sh
+++ b/scripts/tracing/ftrace-bisect.sh
@@ -12,7 +12,7 @@
# (note, if this is a problem with function_graph tracing, then simply
# replace "function" with "function_graph" in the following steps).
#
-# # cd /sys/kernel/debug/tracing
+# # cd /sys/kernel/tracing
# # echo schedule > set_ftrace_filter
# # echo function > current_tracer
#
@@ -35,7 +35,7 @@
#
# Reboot back to test kernel.
#
-# # cd /sys/kernel/debug/tracing
+# # cd /sys/kernel/tracing
# # mv ~/test-file ~/full-file
#
# If it didn't crash.
diff --git a/tools/lib/api/fs/tracing_path.c b/tools/lib/api/fs/tracing_path.c
index 5afb11b30fca..ca95310f7d8e 100644
--- a/tools/lib/api/fs/tracing_path.c
+++ b/tools/lib/api/fs/tracing_path.c
@@ -14,8 +14,8 @@
#include "tracing_path.h"
static char tracing_mnt[PATH_MAX] = "/sys/kernel/debug";
-static char tracing_path[PATH_MAX] = "/sys/kernel/debug/tracing";
-static char tracing_events_path[PATH_MAX] = "/sys/kernel/debug/tracing/events";
+static char tracing_path[PATH_MAX] = "/sys/kernel/tracing";
+static char tracing_events_path[PATH_MAX] = "/sys/kernel/tracing/events";
static void __tracing_path_set(const char *tracing, const char *mountpoint)
{
diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index 8e24c4c78c7f..9532bcf4138d 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -6664,7 +6664,7 @@ static void parse_header_field(const char *field,
* This parses the header page format for information on the
* ring buffer used. The @buf should be copied from
*
- * /sys/kernel/debug/tracing/events/header_page
+ * /sys/kernel/tracing/events/header_page
*/
int tep_parse_header_page(struct tep_handle *tep, char *buf, unsigned long size,
int long_size)
@@ -6758,7 +6758,7 @@ static int find_event_handle(struct tep_handle *tep, struct tep_event *event)
*
* These files currently come from:
*
- * /sys/kernel/debug/tracing/events/.../.../format
+ * /sys/kernel/tracing/events/.../.../format
*/
static enum tep_errno parse_format(struct tep_event **eventp,
struct tep_handle *tep, const char *buf,
@@ -6912,7 +6912,7 @@ __parse_event(struct tep_handle *tep,
*
* These files currently come from:
*
- * /sys/kernel/debug/tracing/events/.../.../format
+ * /sys/kernel/tracing/events/.../.../format
*/
enum tep_errno tep_parse_format(struct tep_handle *tep,
struct tep_event **eventp,
@@ -6934,7 +6934,7 @@ enum tep_errno tep_parse_format(struct tep_handle *tep,
*
* These files currently come from:
*
- * /sys/kernel/debug/tracing/events/.../.../format
+ * /sys/kernel/tracing/events/.../.../format
*/
enum tep_errno tep_parse_event(struct tep_handle *tep, const char *buf,
unsigned long size, const char *sys)
diff --git a/tools/tracing/latency/latency-collector.c b/tools/tracing/latency/latency-collector.c
index 59a7f2346eab..0fd9c747d396 100644
--- a/tools/tracing/latency/latency-collector.c
+++ b/tools/tracing/latency/latency-collector.c
@@ -1584,7 +1584,7 @@ static void *do_printloop(void *arg)
/*
* Toss a coin to decide if we want to sleep before printing
* out the backtrace. The reason for this is that opening
- * /sys/kernel/debug/tracing/trace will cause a blackout of
+ * /sys/kernel/tracing/trace will cause a blackout of
* hundreds of ms, where no latencies will be noted by the
* latency tracer. Thus by randomly sleeping we try to avoid
* missing traces systematically due to this. With this option
--
2.39.1.456.gfc5497dd1b-goog