From patchwork Fri Nov 9 13:31:50 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tzvetomir Stoyanov X-Patchwork-Id: 10759705 Return-Path: Received: from mail-eopbgr810079.outbound.protection.outlook.com ([40.107.81.79]:10688 "EHLO NAM01-BY2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727784AbeKIXMg (ORCPT ); Fri, 9 Nov 2018 18:12:36 -0500 From: Tzvetomir Stoyanov To: "rostedt@goodmis.org" CC: "linux-trace-devel@vger.kernel.org" Subject: [PATCH v2 03/11] tools/lib/traceevent: libtraceevent man pages for tep_handler related APIs Date: Fri, 9 Nov 2018 13:31:50 +0000 Message-ID: <20181109133135.25804-4-tstoyanov@vmware.com> References: <20181109133135.25804-1-tstoyanov@vmware.com> In-Reply-To: <20181109133135.25804-1-tstoyanov@vmware.com> Content-Language: en-US MIME-Version: 1.0 Sender: linux-trace-devel-owner@vger.kernel.org List-ID: Content-Length: 15488 This patch adds 4 new man pages for: tep_register_comm,tep_pid_is_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, as part of the libtraceevent APIs. Signed-off-by: Tzvetomir Stoyanov --- .../Documentation/libtraceevent-commands.txt | 130 ++++++++++++++++++ .../Documentation/libtraceevent-handle.txt | 101 ++++++++++++++ .../Documentation/libtraceevent-long_size.txt | 79 +++++++++++ .../Documentation/libtraceevent-set_flag.txt | 94 +++++++++++++ tools/lib/traceevent/event-parse-api.c | 9 +- 5 files changed, 410 insertions(+), 3 deletions(-) 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..f27151dd3101 --- /dev/null +++ b/tools/lib/traceevent/Documentation/libtraceevent-commands.txt @@ -0,0 +1,130 @@ +libtraceevent(3) +================ + +NAME +---- +tep_register_comm,tep_pid_is_registered,tep_data_comm_from_pid,tep_data_pid_from_comm,tep_cmdline_pid - handle pid to process name mappings + +SYNOPSIS +-------- +[verse] +-- +*#include * + +int *tep_register_comm*(struct tep_handle pass:[*]_tep_, const char pass:[*]_comm_, int _pid_); +int *tep_pid_is_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. It is also saved in trace.dat file. + +The _tep_register_comm()_ function registers a pid / process name mapping. +The _pid_ argument is the process ID, the _comm_ argument is the process name, +_tep_ is the event context. The _comm_ is copied internally. + +The _tep_pid_is_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, or -1 in case of an error. + +_tep_pid_is_registered()_ function returns 1 if the _pid_ has a process name +mapped to it, 0 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 +... +int ls_pid = 1021; +struct tep_handle *tep = tep_alloc(); +... + if (tep_register_comm(tep, "ls", ls_pid) != 0) { + /* Failed to register pid / command mapping */ + } +.... + if (tep_pid_is_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* , author of *libtraceevent*. +*Tzvetomir Stoyanov* , author of this man page. +-- +REPORTING BUGS +-------------- +Report bugs to + +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..4fda29c2e607 --- /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 * + +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 + +... +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* , author of *libtraceevent*. +*Tzvetomir Stoyanov* , author of this man page. +-- +REPORTING BUGS +-------------- +Report bugs to + +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..ce7fb063a8da --- /dev/null +++ b/tools/lib/traceevent/Documentation/libtraceevent-long_size.txt @@ -0,0 +1,79 @@ +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 * + +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. +This information is saved in the trace.dat file. + +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 +... +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* , author of *libtraceevent*. +*Tzvetomir Stoyanov* , author of this man page. +-- +REPORTING BUGS +-------------- +Report bugs to + +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..e5393610cfca --- /dev/null +++ b/tools/lib/traceevent/Documentation/libtraceevent-set_flag.txt @@ -0,0 +1,94 @@ +libtraceevent(3) +================ + +NAME +---- +tep_set_flag - Set a flag or combination of flags of trace event parser context + +SYNOPSIS +-------- +[verse] +-- +*#include * + +enum *tep_flag* { + _TEP_NSEC_OUTPUT_, + _TEP_DISABLE_SYS_PLUGINS_, + _TEP_DISABLE_PLUGINS_ +}; +void *tep_set_flag*(struct tep_handle pass:[*]_tep_, int _flag_); +-- + +DESCRIPTION +----------- +[verse] +-- +The _tep_set_flag()_ function sets _flag_ or any combination of flags to _tep_ context. +Flags are defined in *enum tep_flag*: + _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. +-- + +RETURN VALUE +------------ +_tep_set_flag()_ functions has no return value. + +EXAMPLE +------- +[source,c] +-- +#include +... +struct tep_handle *tep = tep_alloc(); +... +/* Set printing of timestamps in nano seconds and disable system plugins */ +tep_set_flag(tep, TEP_NSEC_OUTPUT | TEP_DISABLE_SYS_PLUGINS); +... +/* Disable all library plugins */ +tep_set_flag(tep, TEP_DISABLE_PLUGINS); +... +-- +FILES +----- +[verse] +-- +*event-parse.h* + Header file to include in order to have access to the library APIs. +*trace-seq.h* + Header file to include in order to have access to trace sequences related APIs. + Trace sequences are used to allow a function to call several other functions + to create a string of data to use. +*-ltraceevent* + Linker switch to add when building a program that uses the library. +-- + +SEE ALSO +-------- +_libtraceevent(3)_, _trace-cmd(1)_ + +AUTHOR +------ +[verse] +-- +*Steven Rostedt* , author of *libtraceevent*. +*Tzvetomir Stoyanov* , author of this man page. +-- +REPORTING BUGS +-------------- +Report bugs to + +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/event-parse-api.c b/tools/lib/traceevent/event-parse-api.c index 52188921cfe3..c0fb86e29aac 100644 --- a/tools/lib/traceevent/event-parse-api.c +++ b/tools/lib/traceevent/event-parse-api.c @@ -140,10 +140,12 @@ void tep_set_cpus(struct tep_handle *pevent, int cpus) } /** - * tep_get_long_size - get the size of a long integer on the current machine + * tep_get_long_size - get the size of a long integer on the machine, + * where the trace is generated * @pevent: a handle to the tep_handle * - * This returns the size of a long integer on the current machine + * This returns the size of a long integer on the machine, + * where the trace is generated * If @pevent is NULL, 0 is returned. */ int tep_get_long_size(struct tep_handle *pevent) @@ -154,7 +156,8 @@ int tep_get_long_size(struct tep_handle *pevent) } /** - * tep_set_long_size - set the size of a long integer on the current machine + * tep_set_long_size - set the size of a long integer on the machine, + * where the trace is generated * @pevent: a handle to the tep_handle * @size: size, in bytes, of a long integer *