From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org, linux-trace-devel@vger.kernel.org
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
Ingo Molnar <mingo@kernel.org>, Jiri Olsa <jolsa@redhat.com>,
Namhyung Kim <namhyung@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
Subject: [PATCH 16/23 v3] tools lib traceevent: Document tep_load_plugins_hook()
Date: Tue, 21 Jul 2020 21:16:44 -0400 [thread overview]
Message-ID: <20200722011754.720060785@goodmis.org> (raw)
In-Reply-To: 20200722011628.925541477@goodmis.org
From: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
Add description of tep_load_plugins_hook() traceevent API. Updated
library man pages with description of the tep_load_plugins_hook() API.
Link: https://lore.kernel.org/r/CAM9d7cgLBWCrEHwz+Lhv5x5EXGcNWB0QQoeGh3OKh2JfR=dV9Q@mail.gmail.com
Link: https://lore.kernel.org/linux-trace-devel/20200714103027.2477584-2-tz.stoyanov@gmail.com
Link: https://lore.kernel.org/linux-trace-devel/20200716092014.2613403-2-tz.stoyanov@gmail.com
Suggested-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
.../Documentation/libtraceevent-plugins.txt | 25 ++++++++++++++++++-
tools/lib/traceevent/event-plugin.c | 16 ++++++++++++
2 files changed, 40 insertions(+), 1 deletion(-)
diff --git a/tools/lib/traceevent/Documentation/libtraceevent-plugins.txt b/tools/lib/traceevent/Documentation/libtraceevent-plugins.txt
index 596032ade31f..4d6394397d92 100644
--- a/tools/lib/traceevent/Documentation/libtraceevent-plugins.txt
+++ b/tools/lib/traceevent/Documentation/libtraceevent-plugins.txt
@@ -3,7 +3,7 @@ libtraceevent(3)
NAME
----
-tep_load_plugins, tep_unload_plugins - Load / unload traceevent plugins.
+tep_load_plugins, tep_unload_plugins, tep_load_plugins_hook - Load / unload traceevent plugins.
SYNOPSIS
--------
@@ -13,6 +13,12 @@ SYNOPSIS
struct tep_plugin_list pass:[*]*tep_load_plugins*(struct tep_handle pass:[*]_tep_);
void *tep_unload_plugins*(struct tep_plugin_list pass:[*]_plugin_list_, struct tep_handle pass:[*]_tep_);
+void *tep_load_plugins_hook*(struct tep_handle pass:[*]_tep_, const char pass:[*]_suffix_,
+ void (pass:[*]_load_plugin_)(struct tep_handle pass:[*]tep,
+ const char pass:[*]path,
+ const char pass:[*]name,
+ void pass:[*]data),
+ void pass:[*]_data_);
--
DESCRIPTION
@@ -22,11 +28,13 @@ directories. The _tep_ argument is trace event parser context.
The plugin directories are :
[verse]
--
+ - Directories, specified in _tep_->plugins_dir with priority TEP_PLUGIN_FIRST
- System's plugin directory, defined at the library compile time. It
depends on the library installation prefix and usually is
_(install_preffix)/lib/traceevent/plugins_
- Directory, defined by the environment variable _TRACEEVENT_PLUGIN_DIR_
- User's plugin directory, located at _~/.local/lib/traceevent/plugins_
+ - Directories, specified in _tep_->plugins_dir with priority TEP_PLUGIN_LAST
--
Loading of plugins can be controlled by the _tep_flags_, using the
_tep_set_flag()_ API:
@@ -44,6 +52,12 @@ _tep_load_plugins()_. The _tep_ argument is trace event parser context. The
_plugin_list_ is the list of loaded plugins, returned by
the _tep_load_plugins()_ function.
+The _tep_load_plugins_hook_ function walks through all directories with plugins
+and calls user specified _load_plugin()_ hook for each plugin file. Only files
+with given _suffix_ are considered to be plugins. The _data_ is a user specified
+context, passed to _load_plugin()_. Directories and the walk order are the same
+as in _tep_load_plugins()_ API.
+
RETURN VALUE
------------
The _tep_load_plugins()_ function returns a list of successfully loaded plugins,
@@ -63,6 +77,15 @@ if (plugins == NULL) {
}
...
tep_unload_plugins(plugins, tep);
+...
+void print_plugin(struct tep_handle *tep, const char *path,
+ const char *name, void *data)
+{
+ pritnf("Found libtraceevent plugin %s/%s\n", path, name);
+}
+...
+tep_load_plugins_hook(tep, ".so", print_plugin, NULL);
+...
--
FILES
diff --git a/tools/lib/traceevent/event-plugin.c b/tools/lib/traceevent/event-plugin.c
index 1d4f1809cf17..aa6f43290cd3 100644
--- a/tools/lib/traceevent/event-plugin.c
+++ b/tools/lib/traceevent/event-plugin.c
@@ -543,6 +543,22 @@ load_plugins_dir(struct tep_handle *tep, const char *suffix,
closedir(dir);
}
+/**
+ * tep_load_plugins_hook - call a user specified callback to load a plugin
+ * @tep: handler to traceevent context
+ * @suffix: filter only plugin files with given suffix
+ * @load_plugin: user specified callback, called for each plugin file
+ * @data: custom context, passed to @load_plugin
+ *
+ * Searches for traceevent plugin files and calls @load_plugin for each
+ * The order of plugins search is:
+ * - Directories, specified in @tep->plugins_dir and priority TEP_PLUGIN_FIRST
+ * - Directory, specified at compile time with PLUGIN_TRACEEVENT_DIR
+ * - Directory, specified by environment variable TRACEEVENT_PLUGIN_DIR
+ * - In user's home: ~/.local/lib/traceevent/plugins/
+ * - Directories, specified in @tep->plugins_dir and priority TEP_PLUGIN_LAST
+ *
+ */
void tep_load_plugins_hook(struct tep_handle *tep, const char *suffix,
void (*load_plugin)(struct tep_handle *tep,
const char *path,
--
2.26.2
next prev parent reply other threads:[~2020-07-22 1:18 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-22 1:16 [PATCH 00/23 v3] tools lib traceevent: Synchronizing trace-cmd with tools Steven Rostedt
2020-07-22 1:16 ` [PATCH 01/23 v3] tools lib traceevent: Add API to read time information from kbuffer Steven Rostedt
2020-07-22 1:16 ` [PATCH 02/23 v3] tools lib traceevent: Add proper KBUFFER_TYPE_TIME_STAMP handling Steven Rostedt
2020-07-22 1:16 ` [PATCH 03/23 v3] tools lib traceevent: Add tep_load_plugins_hook() API Steven Rostedt
2020-07-22 1:16 ` [PATCH 04/23 v3] tools lib traceevent: Add interface for options to plugins Steven Rostedt
2020-07-22 1:16 ` [PATCH 05/23 v3] tools lib traceevent: Introduced new traceevent API, for adding new plugins directories Steven Rostedt
2020-07-22 1:16 ` [PATCH 06/23 v3] tools lib traceevent: Add support for more printk format specifiers Steven Rostedt
2020-07-22 1:16 ` [PATCH 07/23 v3] tools lib traceevent: Optimize pretty_print() function Steven Rostedt
2020-07-22 1:16 ` [PATCH 08/23 v3] tools lib traceevent: Add plugin for tlb_flush Steven Rostedt
2020-07-22 1:16 ` [PATCH 09/23 v3] tools lib traceevent: Add more SVM exit reasons Steven Rostedt
2020-07-22 1:16 ` [PATCH 10/23 v3] tools lib traceevent: Add offset option for function plugin Steven Rostedt
2020-07-22 1:16 ` [PATCH 11/23 v3] tools lib traceevent: Add plugin for decoding syscalls/sys_enter_futex Steven Rostedt
2020-07-22 1:16 ` [PATCH 12/23 v3] tools lib traceevent: Move kernel_stack event handler to "function" plugin Steven Rostedt
2020-07-22 1:16 ` [PATCH 13/23 v3] tools lib traceevent: Add builtin handler for trace_marker_raw Steven Rostedt
2020-07-22 1:16 ` [PATCH 14/23 v3] tools lib traceevent: Change to SPDX License format Steven Rostedt
2020-07-22 1:16 ` [PATCH 15/23 v3] tools lib traceevent: Fix reporting of unknown SVM exit reasons Steven Rostedt
2020-07-22 1:16 ` Steven Rostedt [this message]
2020-07-22 1:16 ` [PATCH 17/23 v3] tools lib traceevent: Handle strdup() error in parse_option_name() Steven Rostedt
2020-07-22 1:16 ` [PATCH 18/23 v3] tools lib traceevent: Fix typo in tep_plugin_add_option() description Steven Rostedt
2020-07-22 1:16 ` [PATCH 19/23 v3] tools lib traceevent: Improve error handling of tep_plugin_add_option() API Steven Rostedt
2020-07-22 1:16 ` [PATCH 20/23 v3] tools lib traceevent: Fixed broken indentation in parse_ip4_print_args() Steven Rostedt
2020-07-22 1:16 ` [PATCH 21/23 v3] tools lib traceevent: Fixed type in PRINT_FMT_STING Steven Rostedt
2020-07-22 1:16 ` [PATCH 22/23 v3] tools lib traceevent: Fixed description of tep_add_plugin_path() API Steven Rostedt
2020-07-22 1:16 ` [PATCH 23/23 v3] tools lib traceevent: Handle possible strdup() error in " Steven Rostedt
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