[tip:perf/core] tools lib traceevent: Man page for host endian APIs

tip-bot for Tzvetomir Stoyanov
2019-05-18T09:04:47Z

Commit-ID: 802e985eb682e766992d2f851e4f1843414b3b0e
Gitweb: https://git.kernel.org/tip/802e985eb682e766992d2f851e4f1843414b3b0e
Author: Tzvetomir Stoyanov <tstoyanov@vmware.com>
AuthorDate: Fri, 10 May 2019 15:56:14 -0400
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Wed, 15 May 2019 16:36:47 -0300

tools lib traceevent: Man page for host endian APIs

Create man pages for libtraceevent APIs:

tep_is_bigendian(),
tep_is_local_bigendian(),
tep_set_local_bigendian()

Signed-off-by: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/linux-trace-devel/20190503091119.23399-8-tstoyanov@vmware.com
Link: http://lkml.kernel.org/r/20190510200107.063709363@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
.../Documentation/libtraceevent-host_endian.txt | 104 +++++++++++++++++++++
1 file changed, 104 insertions(+)

diff --git a/tools/lib/traceevent/Documentation/libtraceevent-host_endian.txt b/tools/lib/traceevent/Documentation/libtraceevent-host_endian.txt
new file mode 100644
index 000000000000..d5d375eb8d1e
--- /dev/null
+++ b/tools/lib/traceevent/Documentation/libtraceevent-host_endian.txt
@@ -0,0 +1,104 @@
+libtraceevent(3)
+================
+
+NAME
+----
+tep_is_bigendian, tep_is_local_bigendian, tep_set_local_bigendian - Get / set
+the endianness of the local machine.
+
+SYNOPSIS
+--------
+[verse]
+--
+*#include <event-parse.h>*
+
+enum *tep_endian* {
+ TEP_LITTLE_ENDIAN = 0,
+ TEP_BIG_ENDIAN
+};
+
+int *tep_is_bigendian*(void);
+bool *tep_is_local_bigendian*(struct tep_handle pass:[*]_tep_);
+void *tep_set_local_bigendian*(struct tep_handle pass:[*]_tep_, enum tep_endian _endian_);
+--
+
+DESCRIPTION
+-----------
+
+The _tep_is_bigendian()_ gets the endianness of the machine, executing
+the function.
+
+The _tep_is_local_bigendian()_ function gets the endianness of the local
+machine, saved in the _tep_ handler. The _tep_ argument is the trace event
+parser context. This API is a bit faster than _tep_is_bigendian()_, as it
+returns cached endianness of the local machine instead of checking it each time.
+
+The _tep_set_local_bigendian()_ function sets the endianness of the local
+machine in the _tep_ handler. The _tep_ argument is trace event parser context.
+The _endian_ argument is the endianness:
+[verse]
+--
+ _TEP_LITTLE_ENDIAN_ - the machine is little endian,
+ _TEP_BIG_ENDIAN_ - the machine is big endian.
+--
+
+RETURN VALUE
+------------
+The _tep_is_bigendian()_ function returns non zero if the endianness of the
+machine, executing the code, is big endian and zero otherwise.
+
+The _tep_is_local_bigendian()_ function returns true, if the endianness of the
+local machine, saved in the _tep_ handler, is big endian, or false otherwise.
+
+EXAMPLE
+-------
+[source,c]
+--
+#include <event-parse.h>
+...
+struct tep_handle *tep = tep_alloc();
+...
+ if (tep_is_bigendian())
+ tep_set_local_bigendian(tep, TEP_BIG_ENDIAN);
+ else
+ tep_set_local_bigendian(tep, TEP_LITTLE_ENDIAN);
+...
+ if (tep_is_local_bigendian(tep))
+ printf("This machine you are running on is bigendian\n");
+ else
+ printf("This machine you are running on is little endian\n");