From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-20.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ECD4DC3526E for ; Thu, 17 Dec 2020 09:47:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AE446238D6 for ; Thu, 17 Dec 2020 09:47:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727275AbgLQJqu (ORCPT ); Thu, 17 Dec 2020 04:46:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49056 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727991AbgLQJqt (ORCPT ); Thu, 17 Dec 2020 04:46:49 -0500 Received: from mail-wr1-x433.google.com (mail-wr1-x433.google.com [IPv6:2a00:1450:4864:20::433]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 23AA6C0611CA for ; Thu, 17 Dec 2020 01:46:34 -0800 (PST) Received: by mail-wr1-x433.google.com with SMTP id r7so25908499wrc.5 for ; Thu, 17 Dec 2020 01:46:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Qk53r8eZIG9FM0whVuWdypgVu0JQXb37mXTB0DUalUI=; b=B+VmNv/ts9LBPVm4PS+olXyFXYKHJgVn5bxQVra/rSzQZkcy8+aiutZNshFHdWBkjh vzlIzD6yeoHL4bWZLyAu2pgI0veaaZRiL2JvtezoZkqS7IV67BeX4KgJlI02L6/Qf0se bAPM3zLWaa+p2tsmK4xexY41iTiX40x2SrShwsXepuKHA3seMXvLaFxd0UPjnDg1lB87 kTdbgDuFYDdCl8DmKnpV2zTngRhoXBbdWWfwbBCHVvSgQr63V6Gtnwa9Z7F/yhEu+bod 1O6fiJLbMLWgsMbQBeL84P2BcMz4THGVuwYfTq6zlH7JBh0mjT7IH9h4yskJ/FxksbDF n3yw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Qk53r8eZIG9FM0whVuWdypgVu0JQXb37mXTB0DUalUI=; b=gHjmiN79srwj8BVYpg/tfdr35JuUVFxxz9hQhJlUR3TklxMZ5lAO9C1jYCGmBGcxMH 6cxaEsksQdudvNUTUX40X+eNpIt7a1D+w5Y3XI2GHYrd3dtS19ERPfl2+klDEgJZmmaV fp7tXkRnWknfhygyRm6nfMF8GC3la/vNeB6/DuK/0u6+7QweuuX4XDwSmlPmQgpsdrF5 ybHeIt7WcvAUfAriF/mJdhRi9MiQkPO4wDjVtyj6SvzQnAS7ZnD4WA0n2Bw0tFmugzVJ RUPN85Xep5FoptD6UTXXcZjfdeFOGV9bFnIZ62A+M/d5UuFhJhfERWJYuj3AguLhSrW2 wAGQ== X-Gm-Message-State: AOAM533P3cr8c1/yNyAQLv2PZdeVyHQNgrRgirSHhniZpqO5XBkzxp4j oKcOKtY1B7Xsd9THIJgjF3c= X-Google-Smtp-Source: ABdhPJzhANg7jLOy4KPxm8prbqIKo50Tjqlaku+8Sc52EIdVBlLwNVNercC+nD9rsJ8pla2dijnC2Q== X-Received: by 2002:a5d:4f0e:: with SMTP id c14mr11392455wru.84.1608198392925; Thu, 17 Dec 2020 01:46:32 -0800 (PST) Received: from oberon.zico.biz ([83.222.187.186]) by smtp.gmail.com with ESMTPSA id o125sm6773164wmo.30.2020.12.17.01.46.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Dec 2020 01:46:32 -0800 (PST) From: "Tzvetomir Stoyanov (VMware)" To: rostedt@goodmis.org Cc: linux-trace-devel@vger.kernel.org Subject: [PATCH 4/9] libtracefs man pages: APIs for working with trace systems and events. Date: Thu, 17 Dec 2020 11:46:21 +0200 Message-Id: <20201217094626.1402191-5-tz.stoyanov@gmail.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201217094626.1402191-1-tz.stoyanov@gmail.com> References: <20201217094626.1402191-1-tz.stoyanov@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org Documented APIs: tracefs_event_systems() tracefs_system_events() tracefs_iterate_raw_events() Signed-off-by: Tzvetomir Stoyanov (VMware) --- Documentation/libtracefs-events.txt | 140 ++++++++++++++++++++++++++++ 1 file changed, 140 insertions(+) create mode 100644 Documentation/libtracefs-events.txt diff --git a/Documentation/libtracefs-events.txt b/Documentation/libtracefs-events.txt new file mode 100644 index 0000000..1fa4674 --- /dev/null +++ b/Documentation/libtracefs-events.txt @@ -0,0 +1,140 @@ +libtracefs(3) +============= + +NAME +---- +tracefs_event_systems, tracefs_system_events, tracefs_iterate_raw_events - +Work with trace systems and events. + +SYNOPSIS +-------- +[verse] +-- +*#include * +*#include * + +char pass:[*]pass:[*]*tracefs_event_systems*(const char pass:[*]_tracing_dir_); +char pass:[*]pass:[*]*tracefs_system_events*(const char pass:[*]_tracing_dir_, const char pass:[*]_system_); +int *tracefs_iterate_raw_events*(struct tep_handle pass:[*]_tep_, struct tracefs_instance pass:[*]_instance_, cpu_set_t pass:[*]_cpus_, int _cpu_size_, int (pass:[*]_callback_)(struct tep_event pass:[*], struct tep_record pass:[*], int, void pass:[*]), void pass:[*]_callback_context_); + +-- + +DESCRIPTION +----------- +Trace systems and events related APIs. + +The _tracefs_event_systems()_ function returns array of strings with the +names of all registered trace systems, located in the given _tracing_dir_ +directory. This could be NULL or tracefs mount point, for trace systems in +top instance, or full path to a trace instance, for trace systems in that +instance. The last entry in the array is a NULL pointer. The array must +be freed with _tracefs_list_free()_ API. + +The _tracefs_system_events()_ function returns array of strings with the +names all registered trace events for given trace system, located in the +given _tracing_dir_ directory. This could be NULL or tracefs mount point, +for trace events in top instance, or full path to a trace instance, for +trace events in that instance. The last entry in the array as a NULL +pointer. The array must be freed with _tracefs_list_free()_ API. + +The _tracefs_iterate_raw_events()_ function iterates through all recorded +events in the raw trace ring buffer. It requires an initialized _tep_ +handler. The ring buffer being iterated is in the given _instance_, or +in the top instance if _instance_ is NULL. It can filter events +for given _cpus_ only, a CPU mask of _cpu_size_ size, or walk through all +recorded events, if _cpus_ is a NULL pointer. The _callback_ is called for +every recorded event from the ring buffer. The _callback_context_ parameter +is passed to the _callback_. Parameters of the _callback_ are _tep_ event +handler; a pointer to recorded event, _struct tep_record_; the _cpu_ on +which the event had been happened and the user specified _callback_context_. +If the _callback_ returns non-zero, the iteration stops. + +RETURN VALUE +------------ +The _tracefs_event_systems()_ and __tracefs_system_events()_ functions return +an array of strings. The last element in that array is a NULL pointer. The array +must be freed with _tracefs_list_free()_ API. In case of an error, NULL is returned. + +The _tracefs_iterate_raw_events()_ function returns -1 in case of an error or +0 otherwise. + +EXAMPLE +------- +[source,c] +-- +#include +#include + +char **systems = tracefs_event_systems(NULL); + + if (systems) { + int i = 0; + /* Got registered trace systems from the top trace instance */ + while (systems[i]) { + char **events = tracefs_system_events(NULL, systems[i]); + if (events) { + /* Got registered events in system[i] from the top trace instance */ + int j = 0; + + while (events[j]) { + /* Got event[j] in system[i] from the top trace instance */ + j++; + } + tracefs_list_free(events); + } + i++; + } + tracefs_list_free(systems); + } +.... +static int records_walk(struct tep_event *tep, struct tep_record *record, int cpu, void *context) +{ + /* Got recorded event on cpu */ + return 0; +} +... +struct tep_event *tep = tracefs_local_events(NULL); + + if (!tep) { + /* Failed to initialise tep handler with local events */ + ... + } + if (tracefs_iterate_raw_events(tep, NULL, NULL, 0, records_walk, NULL) < 0) { + /* Error walking through the recorded raw events */ + } + tep_free(tep); +-- +FILES +----- +[verse] +-- +*tracefs.h* + Header file to include in order to have access to the library APIs. +*-ltracefs* + Linker switch to add when building a program that uses the library. +-- + +SEE ALSO +-------- +_libtracefs(3)_, +_libtraceevent(3)_, +_trace-cmd(1)_ + +AUTHOR +------ +[verse] +-- +*Steven Rostedt* +*Tzvetomir Stoyanov* +-- +REPORTING BUGS +-------------- +Report bugs to + +LICENSE +------- +libtracefs is Free Software licensed under the GNU LGPL 2.1 + +RESOURCES +--------- +https://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git/ \ No newline at end of file -- 2.28.0