* [PATCH v3 1/2] libtracefs man pages: APIs for initializing a tep handler with trace events from the local system.
2020-12-22 4:53 [PATCH v3 0/2] libtracefs man pages Tzvetomir Stoyanov (VMware)
@ 2020-12-22 4:53 ` Tzvetomir Stoyanov (VMware)
2020-12-22 4:53 ` [PATCH v3 2/2] libtracefs man pages: helper APIs for working with trace file system Tzvetomir Stoyanov (VMware)
1 sibling, 0 replies; 3+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2020-12-22 4:53 UTC (permalink / raw)
To: rostedt; +Cc: linux-trace-devel
Documented APIs:
tracefs_local_events()
tracefs_local_events_system()
tracefs_fill_local_events()
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
Documentation/libtracefs-events-tep.txt | 130 ++++++++++++++++++++++++
1 file changed, 130 insertions(+)
create mode 100644 Documentation/libtracefs-events-tep.txt
diff --git a/Documentation/libtracefs-events-tep.txt b/Documentation/libtracefs-events-tep.txt
new file mode 100644
index 0000000..f7d7a61
--- /dev/null
+++ b/Documentation/libtracefs-events-tep.txt
@@ -0,0 +1,130 @@
+libtracefs(3)
+=============
+
+NAME
+----
+tracefs_local_events, tracefs_local_events_system, tracefs_fill_local_events -
+Initialize a tep handler with trace events from the local system.
+
+SYNOPSIS
+--------
+[verse]
+--
+*#include <tracefs.h>*
+
+struct tep_handle pass:[*]*tracefs_local_events*(const char pass:[*]_tracing_dir_);
+struct tep_handle pass:[*]*tracefs_local_events_system*(const char pass:[*]_tracing_dir_, const char pass:[*] const pass:[*]_sys_names_);
+int *tracefs_fill_local_events*(const char pass:[*]_tracing_dir_, struct tep_handle pass:[*]_tep_, int pass:[*]_parsing_failures_);
+
+--
+
+DESCRIPTION
+-----------
+Functions for initializing a tep handler with trace events from the local system.
+
+The _tracefs_local_events()_ function allocates a new _tep_ handler and
+initializes it with events from all trace systems, located in the given
+_tracing_dir_ directory. This could be NULL or the location of the tracefs
+mount point for the trace systems of the local machine, or it may be a path
+to a copy of the tracefs directory from another machine.
+
+The _tracefs_local_events_system()_ function allocates a new _tep_ handler
+and initializes it with events from specified trace systems _sys_names_,
+located in the given _tracing_dir_ directory. This could be NULL or the
+location of the tracefs mount point for the trace systems of the local
+machine, or it may be a path to a copy of the tracefs directory from another
+machine. The _sys_names_ argument is an array of trace system names, that
+will be used for _tep_ handler initialization. The last element in that
+array must be a NULL pointer.
+
+The _tracefs_fill_local_events()_ function initializes already allocated _tep_
+handler with events from all trace systems, located in the given _tracing_dir_
+directory. This could be NULL or the location of the tracefs mount point
+for the trace systems of the local machine, or it may be a path to a copy
+of the tracefs directory from another machine. The _tep_ argument must be
+a pointer to already allocated tep handler, that is going to be initialized.
+The _parsing_failures_ argument could be NULL or a pointer to an integer,
+where the number of failures while parsing the event files are returned.
+
+RETURN VALUE
+------------
+The _tracefs_local_events()_ and _tracefs_local_events_system()_ functions
+return pointer to allocated and initialized _tep_ handler, or NULL in
+case of an error. The returned _tep_ handler must be freed with _tep_free(3)_.
+
+The _tracefs_fill_local_events()_ function returns -1 in case of an error or
+0 otherwise.
+
+EXAMPLE
+-------
+[source,c]
+--
+#include <tracefs.h>
+
+struct tep_event *tep;
+...
+ tep = tracefs_local_events(NULL);
+ if (!tep) {
+ /* Failed to initialise tep handler with local events from top instance */
+ ...
+ }
+...
+ tep_free(tep);
+...
+ const char *systems[] = {"ftrace", "irq", NULL};
+ tep = tracefs_local_events_system(NULL, systems);
+ if (!tep) {
+ /* Failed to initialise tep handler with local events from
+ * ftrace and irq systems in top instance.
+ */
+ ...
+ }
+...
+ tep_free(tep);
+...
+ int parsing_failures;
+ tep = tep_alloc();
+ if (!tep) {
+ /* Failed to allocate a tep handler */
+ ...
+ }
+ if (tracefs_fill_local_events(NULL, tep, &parsing_failures) < 0) {
+ /* Failed to initialise tep handler with local events from top instance */
+ }
+...
+ tep_free(tep);
+--
+FILES
+-----
+[verse]
+--
+*tracefs.h*
+ Header file to include in order to have access to the library APIs.
+*-ltracefs*
+ Linker switch to add when building a program that uses the library.
+--
+
+SEE ALSO
+--------
+_libtracefs(3)_,
+_libtraceevent(3)_,
+_trace-cmd(1)_
+
+AUTHOR
+------
+[verse]
+--
+*Steven Rostedt* <rostedt@goodmis.org>
+*Tzvetomir Stoyanov* <tz.stoyanov@gmail.com>
+--
+REPORTING BUGS
+--------------
+Report bugs to <linux-trace-devel@vger.kernel.org>
+
+LICENSE
+-------
+libtracefs is Free Software licensed under the GNU LGPL 2.1
+
+RESOURCES
+---------
+https://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git/
\ No newline at end of file
--
2.28.0
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH v3 2/2] libtracefs man pages: helper APIs for working with trace file system.
2020-12-22 4:53 [PATCH v3 0/2] libtracefs man pages Tzvetomir Stoyanov (VMware)
2020-12-22 4:53 ` [PATCH v3 1/2] libtracefs man pages: APIs for initializing a tep handler with trace events from the local system Tzvetomir Stoyanov (VMware)
@ 2020-12-22 4:53 ` Tzvetomir Stoyanov (VMware)
1 sibling, 0 replies; 3+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2020-12-22 4:53 UTC (permalink / raw)
To: rostedt; +Cc: linux-trace-devel
Documented APIs:
tracefs_tracers()
tracefs_get_clock()
tracefs_list_free()
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
Documentation/libtracefs-utils.txt | 103 +++++++++++++++++++++++++++++
1 file changed, 103 insertions(+)
create mode 100644 Documentation/libtracefs-utils.txt
diff --git a/Documentation/libtracefs-utils.txt b/Documentation/libtracefs-utils.txt
new file mode 100644
index 0000000..03bc39b
--- /dev/null
+++ b/Documentation/libtracefs-utils.txt
@@ -0,0 +1,103 @@
+libtracefs(3)
+=============
+
+NAME
+----
+tracefs_tracers, tracefs_get_clock, tracefs_list_free -
+Helper functions for working with trace file system.
+
+SYNOPSIS
+--------
+[verse]
+--
+*#include <tracefs.h>*
+
+char pass:[*]pass:[*]*tracefs_tracers*(const char pass:[*]_tracing_dir_);
+char pass:[*]*tracefs_get_clock*(struct tracefs_instance pass:[*]_instance_);
+void *tracefs_list_free*(char pass:[*]pass:[*]_list_);
+--
+
+DESCRIPTION
+-----------
+Various useful functions for working with trace file system.
+
+The _tracefs_tracers()_ function returns array of strings with the
+names of supported tracer plugins, located in the given _tracing_dir_
+directory. This could be NULL or the location of the tracefs mount point
+for the trace systems of the local machine, or it may be a path to a copy
+of the tracefs directory from another machine. The last entry in the array
+as a NULL pointer. The array must be freed with _tracefs_list_free()_ API.
+
+The _tracefs_get_clock()_ function returns name of the current trace clock,
+used in the given _instance_. If _instance_ is NULL, the clock of the main
+trace instance is returned. The returned string must be freed with free().
+
+The _tracefs_list_free()_ function frees an array of strings, returned by
+_tracefs_event_systems()_, _tracefs_system_events()_ and _tracefs_tracers()_
+APIs.
+
+RETURN VALUE
+------------
+The _tracefs_tracers()_ returns array of strings. The last element in that
+array is a NULL pointer. The array must be freed with _tracefs_list_free()_ API.
+In case of an error, NULL is returned.
+
+The _tracefs_get_clock()_ returns string, that must be freed with free(), or NULL
+in case of an error.
+
+EXAMPLE
+-------
+[source,c]
+--
+#include <tracefs.h>
+
+char **tracers = tracefs_tracers(NULL);
+
+ if (tracers) {
+ /* Got tracer plugins from the top trace instance */
+ ...
+ tracefs_list_free(tracers);
+ }
+....
+char *clock = tracefs_get_clock(NULL);
+
+ if (clock) {
+ /* Got current trace clock of the top trace instance */
+ ...
+ free(clock);
+ }
+--
+FILES
+-----
+[verse]
+--
+*tracefs.h*
+ Header file to include in order to have access to the library APIs.
+*-ltracefs*
+ Linker switch to add when building a program that uses the library.
+--
+
+SEE ALSO
+--------
+_libtracefs(3)_,
+_libtraceevent(3)_,
+_trace-cmd(1)_
+
+AUTHOR
+------
+[verse]
+--
+*Steven Rostedt* <rostedt@goodmis.org>
+*Tzvetomir Stoyanov* <tz.stoyanov@gmail.com>
+--
+REPORTING BUGS
+--------------
+Report bugs to <linux-trace-devel@vger.kernel.org>
+
+LICENSE
+-------
+libtracefs is Free Software licensed under the GNU LGPL 2.1
+
+RESOURCES
+---------
+https://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git/
\ No newline at end of file
--
2.28.0
^ permalink raw reply related [flat|nested] 3+ messages in thread