From: Tzvetomir Stoyanov <tstoya...@vmware.com> Added 4 new man pages, describing libtraceevent APIs:
tep_register_comm(), tep_override_comm(), tep_is_pid_registered(), tep_data_comm_from_pid(), tep_data_pid_from_comm(), tep_cmdline_pid(), tep_alloc(), tep_free(), tep_get_long_size(), tep_set_long_size(), tep_set_flag(), tep_clear_flag(), tep_test_flag() Signed-off-by: Tzvetomir Stoyanov <tstoya...@vmware.com> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Jiri Olsa <jo...@redhat.com> Cc: Namhyung Kim <namhy...@kernel.org> Cc: linux-trace-de...@vger.kernel.org Link: http://lore.kernel.org/linux-trace-devel/20190503091119.23399-4-tstoya...@vmware.com Link: http://lkml.kernel.org/r/20190510200106.420270...@goodmis.org Signed-off-by: Steven Rostedt (VMware) <rost...@goodmis.org> Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- .../Documentation/libtraceevent-commands.txt | 153 ++++++++++++++++++ .../Documentation/libtraceevent-handle.txt | 101 ++++++++++++ .../Documentation/libtraceevent-long_size.txt | 78 +++++++++ .../Documentation/libtraceevent-set_flag.txt | 104 ++++++++++++ 4 files changed, 436 insertions(+) create mode 100644 tools/lib/traceevent/Documentation/libtraceevent-commands.txt create mode 100644 tools/lib/traceevent/Documentation/libtraceevent-handle.txt create mode 100644 tools/lib/traceevent/Documentation/libtraceevent-long_size.txt create mode 100644 tools/lib/traceevent/Documentation/libtraceevent-set_flag.txt diff --git a/tools/lib/traceevent/Documentation/libtraceevent-commands.txt b/tools/lib/traceevent/Documentation/libtraceevent-commands.txt new file mode 100644 index 000000000000..bec552001f8e --- /dev/null +++ b/tools/lib/traceevent/Documentation/libtraceevent-commands.txt @@ -0,0 +1,153 @@ +libtraceevent(3) +================ + +NAME +---- +tep_register_comm, tep_override_comm, tep_pid_is_registered, +tep_data_comm_from_pid, tep_data_pid_from_comm, tep_cmdline_pid - +Manage pid to process name mappings. + +SYNOPSIS +-------- +[verse] +-- +*#include <event-parse.h>* + +int *tep_register_comm*(struct tep_handle pass:[*]_tep_, const char pass:[*]_comm_, int _pid_); +int *tep_override_comm*(struct tep_handle pass:[*]_tep_, const char pass:[*]_comm_, int _pid_); +bool *tep_is_pid_registered*(struct tep_handle pass:[*]_tep_, int _pid_); +const char pass:[*]*tep_data_comm_from_pid*(struct tep_handle pass:[*]_pevent_, int _pid_); +struct cmdline pass:[*]*tep_data_pid_from_comm*(struct tep_handle pass:[*]_pevent_, const char pass:[*]_comm_, struct cmdline pass:[*]_next_); +int *tep_cmdline_pid*(struct tep_handle pass:[*]_pevent_, struct cmdline pass:[*]_cmdline_); +-- + +DESCRIPTION +----------- +These functions can be used to handle the mapping between pid and process name. +The library builds a cache of these mappings, which is used to display the name +of the process, instead of its pid. This information can be retrieved from +tracefs/saved_cmdlines file. + +The _tep_register_comm()_ function registers a _pid_ / process name mapping. +If a command with the same _pid_ is already registered, an error is returned. +The _pid_ argument is the process ID, the _comm_ argument is the process name, +_tep_ is the event context. The _comm_ is duplicated internally. + +The _tep_override_comm()_ function registers a _pid_ / process name mapping. +If a process with the same pid is already registered, the process name string is +udapted with the new one. The _pid_ argument is the process ID, the _comm_ +argument is the process name, _tep_ is the event context. The _comm_ is +duplicated internally. + +The _tep_is_pid_registered()_ function checks if a pid has a process name +mapping registered. The _pid_ argument is the process ID, _tep_ is the event +context. + +The _tep_data_comm_from_pid()_ function returns the process name for a given +pid. The _pid_ argument is the process ID, _tep_ is the event context. +The returned string should not be freed, but will be freed when the _tep_ +handler is closed. + +The _tep_data_pid_from_comm()_ function returns a pid for a given process name. +The _comm_ argument is the process name, _tep_ is the event context. +The argument _next_ is the cmdline structure to search for the next pid. +As there may be more than one pid for a given process, the result of this call +can be passed back into a recurring call in the _next_ parameter, to search for +the next pid. If _next_ is NULL, it will return the first pid associated with +the _comm_. The function performs a linear search, so it may be slow. + +The _tep_cmdline_pid()_ function returns the pid associated with a given +_cmdline_. The _tep_ argument is the event context. + +RETURN VALUE +------------ +_tep_register_comm()_ function returns 0 on success. In case of an error -1 is +returned and errno is set to indicate the cause of the problem: ENOMEM, if there +is not enough memory to duplicate the _comm_ or EEXIST if a mapping for this +_pid_ is already registered. + +_tep_override_comm()_ function returns 0 on success. In case of an error -1 is +returned and errno is set to indicate the cause of the problem: ENOMEM, if there +is not enough memory to duplicate the _comm_. + +_tep_is_pid_registered()_ function returns true if the _pid_ has a process name +mapped to it, false otherwise. + +_tep_data_comm_from_pid()_ function returns the process name as string, or the +string "<...>" if there is no mapping for the given pid. + +_tep_data_pid_from_comm()_ function returns a pointer to a struct cmdline, that +holds a pid for a given process, or NULL if none is found. This result can be +passed back into a recurring call as the _next_ parameter of the function. + +_tep_cmdline_pid()_ functions returns the pid for the give cmdline. If _cmdline_ + is NULL, then -1 is returned. + +EXAMPLE +------- +The following example registers pid for command "ls", in context of event _tep_ +and performs various searches for pid / process name mappings: +[source,c] +-- +#include <event-parse.h> +... +int ret; +int ls_pid = 1021; +struct tep_handle *tep = tep_alloc(); +... + ret = tep_register_comm(tep, "ls", ls_pid); + if (ret != 0 && errno == EEXIST) + ret = tep_override_comm(tep, "ls", ls_pid); + if (ret != 0) { + /* Failed to register pid / command mapping */ + } +... + if (tep_is_pid_registered(tep, ls_pid) == 0) { + /* Command mapping for ls_pid is not registered */ + } +... + const char *comm = tep_data_comm_from_pid(tep, ls_pid); + if (comm) { + /* Found process name for ls_pid */ + } +... + int pid; + struct cmdline *cmd = tep_data_pid_from_comm(tep, "ls", NULL); + while (cmd) { + pid = tep_cmdline_pid(tep, cmd); + /* Found pid for process "ls" */ + cmd = tep_data_pid_from_comm(tep, "ls", cmd); + } +-- +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* <rost...@goodmis.org>, author of *libtraceevent*. +*Tzvetomir Stoyanov* <tz.stoya...@gmail.com>, author of this man page. +-- +REPORTING BUGS +-------------- +Report bugs to <linux-trace-de...@vger.kernel.org> + +LICENSE +------- +libtraceevent is Free Software licensed under the GNU LGPL 2.1 + +RESOURCES +--------- +https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git diff --git a/tools/lib/traceevent/Documentation/libtraceevent-handle.txt b/tools/lib/traceevent/Documentation/libtraceevent-handle.txt new file mode 100644 index 000000000000..8d568316847d --- /dev/null +++ b/tools/lib/traceevent/Documentation/libtraceevent-handle.txt @@ -0,0 +1,101 @@ +libtraceevent(3) +================ + +NAME +---- +tep_alloc, tep_free,tep_ref, tep_unref,tep_ref_get - Create, destroy, manage +references of trace event parser context. + +SYNOPSIS +-------- +[verse] +-- +*#include <event-parse.h>* + +struct tep_handle pass:[*]*tep_alloc*(void); +void *tep_free*(struct tep_handle pass:[*]_tep_); +void *tep_ref*(struct tep_handle pass:[*]_tep_); +void *tep_unref*(struct tep_handle pass:[*]_tep_); +int *tep_ref_get*(struct tep_handle pass:[*]_tep_); +-- + +DESCRIPTION +----------- +These are the main functions to create and destroy tep_handle - the main +structure, representing the trace event parser context. This context is used as +the input parameter of most library APIs. + +The _tep_alloc()_ function allocates and initializes the tep context. + +The _tep_free()_ function will decrement the reference of the _tep_ handler. +When there is no more references, then it will free the handler, as well +as clean up all its resources that it had used. The argument _tep_ is +the pointer to the trace event parser context. + +The _tep_ref()_ function adds a reference to the _tep_ handler. + +The _tep_unref()_ function removes a reference from the _tep_ handler. When +the last reference is removed, the _tep_ is destroyed, and all resources that +it had used are cleaned up. + +The _tep_ref_get()_ functions gets the current references of the _tep_ handler. + +RETURN VALUE +------------ +_tep_alloc()_ returns a pointer to a newly created tep_handle structure. +NULL is returned in case there is not enough free memory to allocate it. + +_tep_ref_get()_ returns the current references of _tep_. +If _tep_ is NULL, 0 is returned. + +EXAMPLE +------- +[source,c] +-- +#include <event-parse.h> + +... +struct tep_handle *tep = tep_alloc(); +... +int ref = tep_ref_get(tep); +tep_ref(tep); +if ( (ref+1) != tep_ref_get(tep)) { + /* Something wrong happened, the counter is not incremented by 1 */ +} +tep_unref(tep); +... +tep_free(tep); +... +-- +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* <rost...@goodmis.org>, author of *libtraceevent*. +*Tzvetomir Stoyanov* <tz.stoya...@gmail.com>, author of this man page. +-- +REPORTING BUGS +-------------- +Report bugs to <linux-trace-de...@vger.kernel.org> + +LICENSE +------- +libtraceevent is Free Software licensed under the GNU LGPL 2.1 + +RESOURCES +--------- +https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git diff --git a/tools/lib/traceevent/Documentation/libtraceevent-long_size.txt b/tools/lib/traceevent/Documentation/libtraceevent-long_size.txt new file mode 100644 index 000000000000..01d78ea2519a --- /dev/null +++ b/tools/lib/traceevent/Documentation/libtraceevent-long_size.txt @@ -0,0 +1,78 @@ +libtraceevent(3) +================ + +NAME +---- +tep_get_long_size, tep_set_long_size - Get / set the size of a long integer on +the machine, where the trace is generated, in bytes + +SYNOPSIS +-------- +[verse] +-- +*#include <event-parse.h>* + +int *tep_get_long_size*(strucqt tep_handle pass:[*]_tep_); +void *tep_set_long_size*(struct tep_handle pass:[*]_tep_, int _long_size_); +-- + +DESCRIPTION +----------- +The _tep_get_long_size()_ function returns the size of a long integer on the machine, +where the trace is generated. The _tep_ argument is trace event parser context. + +The _tep_set_long_size()_ function sets the size of a long integer on the machine, +where the trace is generated. The _tep_ argument is trace event parser context. +The _long_size_ is the size of a long integer, in bytes. + +RETURN VALUE +------------ +The _tep_get_long_size()_ function returns the size of a long integer on the machine, +where the trace is generated, in bytes. + +EXAMPLE +------- +[source,c] +-- +#include <event-parse.h> +... +struct tep_handle *tep = tep_alloc(); +... +tep_set_long_size(tep, 4); +... +int long_size = tep_get_long_size(tep); +... +-- + +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* <rost...@goodmis.org>, author of *libtraceevent*. +*Tzvetomir Stoyanov* <tz.stoya...@gmail.com>, author of this man page. +-- +REPORTING BUGS +-------------- +Report bugs to <linux-trace-de...@vger.kernel.org> + +LICENSE +------- +libtraceevent is Free Software licensed under the GNU LGPL 2.1 + +RESOURCES +--------- +https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git diff --git a/tools/lib/traceevent/Documentation/libtraceevent-set_flag.txt b/tools/lib/traceevent/Documentation/libtraceevent-set_flag.txt new file mode 100644 index 000000000000..b0599780b9a6 --- /dev/null +++ b/tools/lib/traceevent/Documentation/libtraceevent-set_flag.txt @@ -0,0 +1,104 @@ +libtraceevent(3) +================ + +NAME +---- +tep_set_flag, tep_clear_flag, tep_test_flag - +Manage flags of trace event parser context. + +SYNOPSIS +-------- +[verse] +-- +*#include <event-parse.h>* + +enum *tep_flag* { + _TEP_NSEC_OUTPUT_, + _TEP_DISABLE_SYS_PLUGINS_, + _TEP_DISABLE_PLUGINS_ +}; +void *tep_set_flag*(struct tep_handle pass:[*]_tep_, enum tep_flag _flag_); +void *tep_clear_flag*(struct tep_handle pass:[*]_tep_, enum tep_flag _flag_); +bool *tep_test_flag*(struct tep_handle pass:[*]_tep_, enum tep_flag _flag_); +-- + +DESCRIPTION +----------- +Trace event parser context flags are defined in *enum tep_flag*: +[verse] +-- +_TEP_NSEC_OUTPUT_ - print event's timestamp in nano seconds, instead of micro seconds. +_TEP_DISABLE_SYS_PLUGINS_ - disable plugins, located in system's plugin + directory. This directory is defined at library compile + time, and usually depends on library installation + prefix: (install_preffix)/lib/traceevent/plugins +_TEP_DISABLE_PLUGINS_ - disable all library plugins: + - in system's plugin directory + - in directory, defined by the environment variable _TRACEEVENT_PLUGIN_DIR_ + - in user's home directory, _~/.traceevent/plugins_ +-- +Note: plugin related flags must me set before calling _tep_load_plugins()_ API. + +The _tep_set_flag()_ function sets _flag_ to _tep_ context. + +The _tep_clear_flag()_ function clears _flag_ from _tep_ context. + +The _tep_test_flag()_ function tests if _flag_ is set to _tep_ context. + +RETURN VALUE +------------ +_tep_test_flag()_ function returns true if _flag_ is set, false otherwise. + +EXAMPLE +------- +[source,c] +-- +#include <event-parse.h> +... +struct tep_handle *tep = tep_alloc(); +... +/* Print timestamps in nanoseconds */ +tep_set_flag(tep, TEP_NSEC_OUTPUT); +... +if (tep_test_flag(tep, TEP_NSEC_OUTPUT)) { + /* print timestamps in nanoseconds */ +} else { + /* print timestamps in microseconds */ +} +... +/* Print timestamps in microseconds */ +tep_clear_flag(tep, TEP_NSEC_OUTPUT); +... +-- +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* <rost...@goodmis.org>, author of *libtraceevent*. +*Tzvetomir Stoyanov* <tz.stoya...@gmail.com>, author of this man page. +-- +REPORTING BUGS +-------------- +Report bugs to <linux-trace-de...@vger.kernel.org> + +LICENSE +------- +libtraceevent is Free Software licensed under the GNU LGPL 2.1 + +RESOURCES +--------- +https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git -- 2.20.1
