From patchwork Fri May 10 19:56:26 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 10939465 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 921C1112C for ; Fri, 10 May 2019 20:02:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 81CF528C9B for ; Fri, 10 May 2019 20:02:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 756CA28CCC; Fri, 10 May 2019 20:02:00 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CA23D28C9B for ; Fri, 10 May 2019 20:01:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727982AbfEJUBy (ORCPT ); Fri, 10 May 2019 16:01:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:55190 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727943AbfEJUBL (ORCPT ); Fri, 10 May 2019 16:01:11 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 055EB217F5; Fri, 10 May 2019 20:01:10 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.92) (envelope-from ) id 1hPBhd-0006nH-5C; Fri, 10 May 2019 16:01:09 -0400 Message-Id: <20190510200109.054708419@goodmis.org> User-Agent: quilt/0.65 Date: Fri, 10 May 2019 15:56:26 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-devel@vger.kernel.org Cc: Arnaldo Carvalho de Melo , Ingo Molnar , Jiri Olsa , Namhyung Kim , Andrew Morton , Tzvetomir Stoyanov Subject: [PATCH 20/27] tools/lib/traceevent: Man pages for print field APIs References: <20190510195606.537643615@goodmis.org> MIME-Version: 1.0 Sender: linux-trace-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Tzvetomir Stoyanov Create man pages for libtraceevent APIs: tep_print_field(), tep_print_fields(), tep_print_num_field(), tep_print_func_field() Link: http://lore.kernel.org/linux-trace-devel/20190503091119.23399-20-tstoyanov@vmware.com Signed-off-by: Tzvetomir Stoyanov Signed-off-by: Steven Rostedt (VMware) --- .../libtraceevent-field_print.txt | 126 ++++++++++++++++++ 1 file changed, 126 insertions(+) create mode 100644 tools/lib/traceevent/Documentation/libtraceevent-field_print.txt diff --git a/tools/lib/traceevent/Documentation/libtraceevent-field_print.txt b/tools/lib/traceevent/Documentation/libtraceevent-field_print.txt new file mode 100644 index 000000000000..9a9df98ac44d --- /dev/null +++ b/tools/lib/traceevent/Documentation/libtraceevent-field_print.txt @@ -0,0 +1,126 @@ +libtraceevent(3) +================ + +NAME +---- +tep_print_field, tep_print_fields, tep_print_num_field, tep_print_func_field - +Print the field content. + +SYNOPSIS +-------- +[verse] +-- +*#include * +*#include * + +void *tep_print_field*(struct trace_seq pass:[*]_s_, void pass:[*]_data_, struct tep_format_field pass:[*]_field_); +void *tep_print_fields*(struct trace_seq pass:[*]_s_, void pass:[*]_data_, int _size_, struct tep_event pass:[*]_event_); +int *tep_print_num_field*(struct trace_seq pass:[*]_s_, const char pass:[*]_fmt_, struct tep_event pass:[*]_event_, const char pass:[*]_name_, struct tep_record pass:[*]_record_, int _err_); +int *tep_print_func_field*(struct trace_seq pass:[*]_s_, const char pass:[*]_fmt_, struct tep_event pass:[*]_event_, const char pass:[*]_name_, struct tep_record pass:[*]_record_, int _err_); +-- + +DESCRIPTION +----------- +These functions print recorded field's data, according to the field's type. + +The _tep_print_field()_ function extracts from the recorded raw _data_ value of +the _field_ and prints it into _s_, according to the field type. + +The _tep_print_fields()_ prints each field name followed by the record's field +value according to the field's type: +[verse] +-- +"field1_name=field1_value field2_name=field2_value ..." +-- +It iterates all fields of the _event_, and calls _tep_print_field()_ for each of +them. + +The _tep_print_num_field()_ function prints a numeric field with given format +string. A search is performed in the _event_ for a field with _name_. If such +field is found, its value is extracted from the _record_ and is printed in the +_s_, according to the given format string _fmt_. If the argument _err_ is +non-zero, and an error occures - it is printed in the _s_. + +The _tep_print_func_field()_ function prints a function field with given format +string. A search is performed in the _event_ for a field with _name_. If such +field is found, its value is extracted from the _record_. The value is assumed +to be a function address, and a search is perform to find the name of this +function. The function name (if found) and its address are printed in the _s_, +according to the given format string _fmt_. If the argument _err_ is non-zero, +and an error occures - it is printed in _s_. + +RETURN VALUE +------------ +The _tep_print_num_field()_ and _tep_print_func_field()_ functions return 1 +on success, -1 in case of an error or 0 if the print buffer _s_ is full. + +EXAMPLE +------- +[source,c] +-- +#include +#include +... +struct tep_handle *tep = tep_alloc(); +... +struct trace_seq seq; +trace_seq_init(&seq); +struct tep_event *event = tep_find_event_by_name(tep, "timer", "hrtimer_start"); +... +void process_record(struct tep_record *record) +{ + struct tep_format_field *field_pid = tep_find_common_field(event, "common_pid"); + + trace_seq_reset(&seq); + + /* Print the value of "common_pid" */ + tep_print_field(&seq, record->data, field_pid); + + /* Print all fields of the "hrtimer_start" event */ + tep_print_fields(&seq, record->data, record->size, event); + + /* Print the value of "expires" field with custom format string */ + tep_print_num_field(&seq, " timer expires in %llu ", event, "expires", record, 0); + + /* Print the address and the name of "function" field with custom format string */ + tep_print_func_field(&seq, " timer function is %s ", event, "function", record, 0); + } + ... +-- + +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