* [PATCH v2 1/4] libtraceevent: Add log levels
2021-05-07 9:50 [PATCH v2 0/4] Add severity to library logs Tzvetomir Stoyanov (VMware)
@ 2021-05-07 9:50 ` Tzvetomir Stoyanov (VMware)
2021-05-07 9:50 ` [PATCH v2 2/4] libtraceevent: Add logs with severity info Tzvetomir Stoyanov (VMware)
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2021-05-07 9:50 UTC (permalink / raw)
To: rostedt; +Cc: linux-trace-devel
Defined levels of the library logs and new API to set the desired log
level. By default, only critical logs are enabled.
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
src/event-parse.h | 12 ++++++++++++
src/parse-utils.c | 16 ++++++++++++++++
2 files changed, 28 insertions(+)
diff --git a/src/event-parse.h b/src/event-parse.h
index 05b156b..77be2b9 100644
--- a/src/event-parse.h
+++ b/src/event-parse.h
@@ -749,4 +749,16 @@ int tep_filter_copy(struct tep_event_filter *dest, struct tep_event_filter *sour
int tep_filter_compare(struct tep_event_filter *filter1, struct tep_event_filter *filter2);
+/* Control library logs */
+enum tep_loglevel {
+ TEP_LOG_NONE = 0,
+ TEP_LOG_CRITICAL,
+ TEP_LOG_ERROR,
+ TEP_LOG_WARNING,
+ TEP_LOG_INFO,
+ TEP_LOG_DEBUG,
+ TEP_LOG_ALL
+};
+void tep_set_loglevel(enum tep_loglevel level);
+
#endif /* _PARSE_EVENTS_H */
diff --git a/src/parse-utils.c b/src/parse-utils.c
index 6a4a2cd..bc89c44 100644
--- a/src/parse-utils.c
+++ b/src/parse-utils.c
@@ -9,8 +9,21 @@
#include <stdarg.h>
#include <errno.h>
+#include "event-parse.h"
+
#define __weak __attribute__((weak))
+static int log_level = TEP_LOG_CRITICAL;
+
+/**
+ * tep_set_loglevel - set log level of the library
+ * @level: desired level of the library messages
+ */
+void tep_set_loglevel(enum tep_loglevel level)
+{
+ log_level = level;
+}
+
int __weak tep_vwarning(const char *name, const char *fmt, va_list ap)
{
int ret = errno;
@@ -29,6 +42,9 @@ void __weak tep_warning(const char *fmt, ...)
{
va_list ap;
+ if (log_level < TEP_LOG_WARNING)
+ return;
+
va_start(ap, fmt);
tep_vwarning("libtraceevent", fmt, ap);
va_end(ap);
--
2.31.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v2 2/4] libtraceevent: Add logs with severity info
2021-05-07 9:50 [PATCH v2 0/4] Add severity to library logs Tzvetomir Stoyanov (VMware)
2021-05-07 9:50 ` [PATCH v2 1/4] libtraceevent: Add log levels Tzvetomir Stoyanov (VMware)
@ 2021-05-07 9:50 ` Tzvetomir Stoyanov (VMware)
2021-05-07 9:50 ` [PATCH v2 3/4] libtraceevent: Rename tep_vwarning() to tep_vprint() Tzvetomir Stoyanov (VMware)
2021-05-07 9:50 ` [PATCH v2 4/4] libtraceevent: Document new log functionality Tzvetomir Stoyanov (VMware)
3 siblings, 0 replies; 6+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2021-05-07 9:50 UTC (permalink / raw)
To: rostedt; +Cc: linux-trace-devel
Renamed existing pr_stat() internal function to tep_info() and limit it
to print only when the log level is TEP_LOG_INFO. Removed duplicated and
unused functions:
vpr_stat()
__pr_stat()
__vpr_stat()
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
src/event-parse.c | 14 +++++++-------
src/event-plugin.c | 2 +-
src/event-utils.h | 7 +------
src/parse-utils.c | 24 ++++--------------------
4 files changed, 13 insertions(+), 34 deletions(-)
diff --git a/src/event-parse.c b/src/event-parse.c
index 88ec909..97c1a97 100644
--- a/src/event-parse.c
+++ b/src/event-parse.c
@@ -6927,8 +6927,8 @@ static int find_event_handle(struct tep_handle *tep, struct tep_event *event)
if (!(*next))
return 0;
- pr_stat("overriding event (%d) %s:%s with new print handler",
- event->id, event->system, event->name);
+ tep_info("overriding event (%d) %s:%s with new print handler",
+ event->id, event->system, event->name);
event->handler = handle->func;
event->context = handle->context;
@@ -7404,7 +7404,7 @@ int tep_register_print_function(struct tep_handle *tep,
* plugins updating the function. This overrides the
* system defaults.
*/
- pr_stat("override of function helper '%s'", name);
+ tep_info("override of function helper '%s'", name);
remove_func_handler(tep, name);
}
@@ -7542,8 +7542,8 @@ int tep_register_event_handler(struct tep_handle *tep, int id,
if (event == NULL)
goto not_found;
- pr_stat("overriding event (%d) %s:%s with new print handler",
- event->id, event->system, event->name);
+ tep_info("overriding event (%d) %s:%s with new print handler",
+ event->id, event->system, event->name);
event->handler = func;
event->context = context;
@@ -7628,8 +7628,8 @@ int tep_unregister_event_handler(struct tep_handle *tep, int id,
goto not_found;
if (event->handler == func && event->context == context) {
- pr_stat("removing override handler for event (%d) %s:%s. Going back to default handler.",
- event->id, event->system, event->name);
+ tep_info("removing override handler for event (%d) %s:%s. Going back to default handler.",
+ event->id, event->system, event->name);
event->handler = NULL;
event->context = NULL;
diff --git a/src/event-plugin.c b/src/event-plugin.c
index df4a0a3..f42243f 100644
--- a/src/event-plugin.c
+++ b/src/event-plugin.c
@@ -497,7 +497,7 @@ load_plugin(struct tep_handle *tep, const char *path,
list->name = plugin;
*plugin_list = list;
- pr_stat("registering plugin: %s", plugin);
+ tep_info("registering plugin: %s", plugin);
func(tep);
return;
diff --git a/src/event-utils.h b/src/event-utils.h
index ff4d6c4..1951557 100644
--- a/src/event-utils.h
+++ b/src/event-utils.h
@@ -9,15 +9,10 @@
#include <ctype.h>
#include <stdarg.h>
+void tep_info(const char *fmt, ...);
/* Can be overridden */
void tep_warning(const char *fmt, ...);
int tep_vwarning(const char *name, const char *fmt, va_list ap);
-void pr_stat(const char *fmt, ...);
-void vpr_stat(const char *fmt, va_list ap);
-
-/* Always available */
-void __pr_stat(const char *fmt, ...);
-void __vpr_stat(const char *fmt, ...);
#define min(x, y) ({ \
typeof(x) _min1 = (x); \
diff --git a/src/parse-utils.c b/src/parse-utils.c
index bc89c44..b997823 100644
--- a/src/parse-utils.c
+++ b/src/parse-utils.c
@@ -50,31 +50,15 @@ void __weak tep_warning(const char *fmt, ...)
va_end(ap);
}
-void __vpr_stat(const char *fmt, va_list ap)
-{
- vprintf(fmt, ap);
- printf("\n");
-}
-void __pr_stat(const char *fmt, ...)
+void tep_info(const char *fmt, ...)
{
va_list ap;
- va_start(ap, fmt);
- __vpr_stat(fmt, ap);
- va_end(ap);
-}
-
-void __weak vpr_stat(const char *fmt, va_list ap)
-{
- __vpr_stat(fmt, ap);
-}
-
-void __weak pr_stat(const char *fmt, ...)
-{
- va_list ap;
+ if (log_level < TEP_LOG_INFO)
+ return;
va_start(ap, fmt);
- __vpr_stat(fmt, ap);
+ tep_vwarning("libtraceevent", fmt, ap);
va_end(ap);
}
--
2.31.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v2 3/4] libtraceevent: Rename tep_vwarning() to tep_vprint()
2021-05-07 9:50 [PATCH v2 0/4] Add severity to library logs Tzvetomir Stoyanov (VMware)
2021-05-07 9:50 ` [PATCH v2 1/4] libtraceevent: Add log levels Tzvetomir Stoyanov (VMware)
2021-05-07 9:50 ` [PATCH v2 2/4] libtraceevent: Add logs with severity info Tzvetomir Stoyanov (VMware)
@ 2021-05-07 9:50 ` Tzvetomir Stoyanov (VMware)
2021-05-13 1:52 ` Steven Rostedt
2021-05-07 9:50 ` [PATCH v2 4/4] libtraceevent: Document new log functionality Tzvetomir Stoyanov (VMware)
3 siblings, 1 reply; 6+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2021-05-07 9:50 UTC (permalink / raw)
To: rostedt; +Cc: linux-trace-devel
Renamed the existing weak function tep_vwarning() to tep_vprint(), to
match its purpose. This function is used to print library logs with any
log severity, not only warnings.
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
src/event-utils.h | 5 +++--
src/parse-utils.c | 27 ++++++++++++++++++++++-----
2 files changed, 25 insertions(+), 7 deletions(-)
diff --git a/src/event-utils.h b/src/event-utils.h
index 1951557..0617a28 100644
--- a/src/event-utils.h
+++ b/src/event-utils.h
@@ -9,10 +9,11 @@
#include <ctype.h>
#include <stdarg.h>
+void tep_warning(const char *fmt, ...);
void tep_info(const char *fmt, ...);
/* Can be overridden */
-void tep_warning(const char *fmt, ...);
-int tep_vwarning(const char *name, const char *fmt, va_list ap);
+int tep_vprint(const char *name, enum tep_loglevel level,
+ bool print_err, const char *fmt, va_list ap);
#define min(x, y) ({ \
typeof(x) _min1 = (x); \
diff --git a/src/parse-utils.c b/src/parse-utils.c
index b997823..7510157 100644
--- a/src/parse-utils.c
+++ b/src/parse-utils.c
@@ -24,11 +24,28 @@ void tep_set_loglevel(enum tep_loglevel level)
log_level = level;
}
-int __weak tep_vwarning(const char *name, const char *fmt, va_list ap)
+/**
+ * tep_vprint - print library log messages
+ * @name: name of the library.
+ * @level: severity of the log message. This parameter is not used in this implementation, but as
+ * the function is weak and can be overridden, having the log level could be useful
+ * for other implementations.
+ * @print_err: whether to print the errno, if non zero.
+ * @fmt: printf format string of the message.
+ * @ap: list of printf parameters.
+ *
+ * This function is used to print all messages from traceevent, tracefs and trace-cmd libraries.
+ * It is defined as weak, so the application that uses those libraries can override it in order
+ * to implement its own logic for printing library logs.
+ *
+ * Return the value of errno at the function enter.
+ */
+int __weak tep_vprint(const char *name, enum tep_loglevel level,
+ bool print_err, const char *fmt, va_list ap)
{
int ret = errno;
- if (errno)
+ if (errno && print_err)
perror(name);
fprintf(stderr, " ");
@@ -38,7 +55,7 @@ int __weak tep_vwarning(const char *name, const char *fmt, va_list ap)
return ret;
}
-void __weak tep_warning(const char *fmt, ...)
+void tep_warning(const char *fmt, ...)
{
va_list ap;
@@ -46,7 +63,7 @@ void __weak tep_warning(const char *fmt, ...)
return;
va_start(ap, fmt);
- tep_vwarning("libtraceevent", fmt, ap);
+ tep_vprint("libtraceevent", TEP_LOG_WARNING, true, fmt, ap);
va_end(ap);
}
@@ -59,6 +76,6 @@ void tep_info(const char *fmt, ...)
return;
va_start(ap, fmt);
- tep_vwarning("libtraceevent", fmt, ap);
+ tep_vprint("libtraceevent", TEP_LOG_INFO, false, fmt, ap);
va_end(ap);
}
--
2.31.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v2 3/4] libtraceevent: Rename tep_vwarning() to tep_vprint()
2021-05-07 9:50 ` [PATCH v2 3/4] libtraceevent: Rename tep_vwarning() to tep_vprint() Tzvetomir Stoyanov (VMware)
@ 2021-05-13 1:52 ` Steven Rostedt
0 siblings, 0 replies; 6+ messages in thread
From: Steven Rostedt @ 2021-05-13 1:52 UTC (permalink / raw)
To: Tzvetomir Stoyanov (VMware); +Cc: linux-trace-devel
On Fri, 7 May 2021 12:50:21 +0300
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> wrote:
> diff --git a/src/event-utils.h b/src/event-utils.h
> index 1951557..0617a28 100644
> --- a/src/event-utils.h
> +++ b/src/event-utils.h
> @@ -9,10 +9,11 @@
> #include <ctype.h>
> #include <stdarg.h>
>
> +void tep_warning(const char *fmt, ...);
> void tep_info(const char *fmt, ...);
> /* Can be overridden */
> -void tep_warning(const char *fmt, ...);
> -int tep_vwarning(const char *name, const char *fmt, va_list ap);
> +int tep_vprint(const char *name, enum tep_loglevel level,
> + bool print_err, const char *fmt, va_list ap);
>
> #define min(x, y) ({ \
> typeof(x) _min1 = (x); \
I have the following build error on trace-cmd:
In file included from trace-util.c:23:
/usr/local/include/traceevent/event-utils.h:16:9: error: unknown type name ‘bool’
16 | bool print_err, const char *fmt, va_list ap);
| ^~~~
Needs to include <stdbool.h> in event-utils.h, can not rely that this
would exist in the use cases.
I'll add it to this patch, unless I find other issues for a v3.
-- Steve
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v2 4/4] libtraceevent: Document new log functionality
2021-05-07 9:50 [PATCH v2 0/4] Add severity to library logs Tzvetomir Stoyanov (VMware)
` (2 preceding siblings ...)
2021-05-07 9:50 ` [PATCH v2 3/4] libtraceevent: Rename tep_vwarning() to tep_vprint() Tzvetomir Stoyanov (VMware)
@ 2021-05-07 9:50 ` Tzvetomir Stoyanov (VMware)
3 siblings, 0 replies; 6+ messages in thread
From: Tzvetomir Stoyanov (VMware) @ 2021-05-07 9:50 UTC (permalink / raw)
To: rostedt; +Cc: linux-trace-devel
Updated man pages with the new log API and log levels.
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
Documentation/libtraceevent-log.txt | 90 +++++++++++++++++++++++++++++
Documentation/libtraceevent.txt | 3 +
2 files changed, 93 insertions(+)
create mode 100644 Documentation/libtraceevent-log.txt
diff --git a/Documentation/libtraceevent-log.txt b/Documentation/libtraceevent-log.txt
new file mode 100644
index 0000000..0aee21d
--- /dev/null
+++ b/Documentation/libtraceevent-log.txt
@@ -0,0 +1,90 @@
+libtraceevent(3)
+================
+
+NAME
+----
+tep_set_loglevel - Set log level of the library
+
+SYNOPSIS
+--------
+[verse]
+--
+*#include <event-parse.h>*
+
+enum *tep_loglevel* {
+ TEP_LOG_NONE = 0,
+ TEP_LOG_CRITICAL,
+ TEP_LOG_ERROR,
+ TEP_LOG_WARNING,
+ TEP_LOG_INFO,
+ TEP_LOG_DEBUG,
+ TEP_LOG_ALL
+};
+
+int *tep_set_loglevel*(enum tep_loglevel _level_);
+
+--
+DESCRIPTION
+-----------
+The _tep_set_loglevel()_ function sets the level of the library logs that will be printed
+on the console. Library log levels are:
+[verse]
+--
+ _TEP_LOG_NONE_ - Do not print any logs.
+ _TEP_LOG_CRITICAL_ - Print critical logs, problem that may case a crash.
+ _TEP_LOG_ERROR_ - Print error logs, problem that could break the main logic of an API.
+ _TEP_LOG_WARNING_ - Print warnings, problem that could limit the result of an API.
+ _TEP_LOG_INFO_ - Print information about normal execution of an API.
+ _TEP_LOG_DEBUG_ - Print debug information.
+ _TEP_LOG_ALL_ - Print logs from all levels.
+--
+Setting the log level to specific value means that logs from the previous levels will be printed
+too. For example _TEP_LOG_WARNING_ will print any logs with severity _TEP_LOG_WARNING_,
+_TEP_LOG_ERROR_ and _TEP_LOG_CRITICAL_. The default log level is _TEP_LOG_CRITICAL_.
+
+
+EXAMPLE
+-------
+[source,c]
+--
+#include <event-parse.h>
+
+tep_set_loglevel(TEP_LOG_ALL);
+...
+/* call libtraceevent APIs and observe any logs they produce */
+...
+tep_set_loglevel(TEP_LOG_CRITICAL);
+--
+
+FILES
+-----
+[verse]
+--
+*event-parse.h*
+ Header file to include in order to have access to the library APIs.
+*-ltraceevent*
+ Linker switch to add when building a program that uses the library.
+--
+
+SEE ALSO
+--------
+_libtraceevent(3)_, _trace-cmd(1)_
+
+AUTHOR
+------
+[verse]
+--
+*Steven Rostedt* <rostedt@goodmis.org>, author of *libtraceevent*.
+*Tzvetomir Stoyanov* <tz.stoyanov@gmail.com>, author of this man page.
+--
+REPORTING BUGS
+--------------
+Report bugs to <linux-trace-devel@vger.kernel.org>
+
+LICENSE
+-------
+libtraceevent is Free Software licensed under the GNU LGPL 2.1
+
+RESOURCES
+---------
+https://git.kernel.org/pub/scm/libs/libtrace/libtraceevent.git/
diff --git a/Documentation/libtraceevent.txt b/Documentation/libtraceevent.txt
index 3365455..d42b5c9 100644
--- a/Documentation/libtraceevent.txt
+++ b/Documentation/libtraceevent.txt
@@ -127,6 +127,9 @@ Endian related APIs:
bool *tep_is_local_bigendian*(struct tep_handle pass:[*]_tep_);
void *tep_set_local_bigendian*(struct tep_handle pass:[*]_tep_, enum tep_endian _endian_);
+Control library logs:
+ int *tep_set_loglevel*(enum tep_loglevel _level_);
+
Trace sequences:
*#include <trace-seq.h>*
void *trace_seq_init*(struct trace_seq pass:[*]_s_);
--
2.31.1
^ permalink raw reply related [flat|nested] 6+ messages in thread