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=-14.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,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 BCBA1C04AB4 for ; Fri, 17 May 2019 19:38:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 88CF42166E for ; Fri, 17 May 2019 19:38:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558121891; bh=UX50jR1VytJVQQxer7LjamI6OiE4kGXkWTXxYQGWl2Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=dSHmpPfd/6ejhQC50WHAdhGZ9Jeb08+A93cw24yXQ+7O0k7+qLqdGEpOhzSS1rjB4 n8q446IbiPNUzPols7Kf2HdOGGeoNR/ZWWYaLgMuuNxKd50oKyc2/yW58lgBsUDxo9 McVBmm+I6Fpw3aOwOplZRQ7moNeM/mPL3G4oXvRs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729652AbfEQTiK (ORCPT ); Fri, 17 May 2019 15:38:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:54012 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727771AbfEQTiJ (ORCPT ); Fri, 17 May 2019 15:38:09 -0400 Received: from quaco.ghostprotocols.net (unknown [190.15.121.82]) (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 9019C21726; Fri, 17 May 2019 19:38:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1558121887; bh=UX50jR1VytJVQQxer7LjamI6OiE4kGXkWTXxYQGWl2Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dJF+t5BaR9x8HOQ2vT8BA3y9KEJSGJKuzc1WrXsj+f06kKaA5Ci9sXLJajKn7vHkQ DxzgGv9qnW70syLJaiOxwIauwaDgkc08BnsD+EG8HbNmprqHb+KMtUSRKx83p5O+ke WYnUighbJN3ehk1rS1/O3hixJDW7F+KAp5PDFN4U= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Tzvetomir Stoyanov , Andrew Morton , Jiri Olsa , linux-trace-devel@vger.kernel.org, Steven Rostedt , Arnaldo Carvalho de Melo Subject: [PATCH 24/73] tools lib traceevent: Man page for header_page APIs Date: Fri, 17 May 2019 16:35:22 -0300 Message-Id: <20190517193611.4974-25-acme@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190517193611.4974-1-acme@kernel.org> References: <20190517193611.4974-1-acme@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tzvetomir Stoyanov Create a man page for libtraceevent APIs: tep_get_header_page_size(), tep_get_header_timestamp_size(), tep_is_old_format() Signed-off-by: Tzvetomir Stoyanov Cc: Andrew Morton Cc: Jiri Olsa Cc: Namhyung Kim Cc: linux-trace-devel@vger.kernel.org Link: http://lore.kernel.org/linux-trace-devel/20190503091119.23399-5-tstoyanov@vmware.com Link: http://lkml.kernel.org/r/20190510200106.583928896@goodmis.org Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Arnaldo Carvalho de Melo --- .../libtraceevent-header_page.txt | 102 ++++++++++++++++++ 1 file changed, 102 insertions(+) create mode 100644 tools/lib/traceevent/Documentation/libtraceevent-header_page.txt diff --git a/tools/lib/traceevent/Documentation/libtraceevent-header_page.txt b/tools/lib/traceevent/Documentation/libtraceevent-header_page.txt new file mode 100644 index 000000000000..615d117dc39f --- /dev/null +++ b/tools/lib/traceevent/Documentation/libtraceevent-header_page.txt @@ -0,0 +1,102 @@ +libtraceevent(3) +================ + +NAME +---- +tep_get_header_page_size, tep_get_header_timestamp_size, tep_is_old_format - +Get the data stored in the header page, in kernel context. + +SYNOPSIS +-------- +[verse] +-- +*#include * + +int *tep_get_header_page_size*(struct tep_handle pass:[*]_tep_); +int *tep_get_header_timestamp_size*(struct tep_handle pass:[*]_tep_); +bool *tep_is_old_format*(struct tep_handle pass:[*]_tep_); +-- +DESCRIPTION +----------- +These functions retrieve information from kernel context, stored in tracefs +events/header_page. Old kernels do not have header page info, so default values +from user space context are used. + +The _tep_get_header_page_size()_ function returns the size of a long integer, +in kernel context. The _tep_ argument is trace event parser context. +This information is retrieved from tracefs events/header_page, "commit" field. + +The _tep_get_header_timestamp_size()_ function returns the size of timestamps, +in kernel context. The _tep_ argument is trace event parser context. This +information is retrieved from tracefs events/header_page, "timestamp" field. + +The _tep_is_old_format()_ function returns true if the kernel predates +the addition of events/header_page, otherwise it returns false. + +RETURN VALUE +------------ +The _tep_get_header_page_size()_ function returns the size of a long integer, +in bytes. + +The _tep_get_header_timestamp_size()_ function returns the size of timestamps, +in bytes. + +The _tep_is_old_format()_ function returns true, if an old kernel is used to +generate the tracing data, which has no event/header_page. If the kernel is new, +or _tep_ is NULL, false is returned. + +EXAMPLE +------- +[source,c] +-- +#include +... +struct tep_handle *tep = tep_alloc(); +... + int longsize; + int timesize; + bool old; + + longsize = tep_get_header_page_size(tep); + timesize = tep_get_header_timestamp_size(tep); + old = tep_is_old_format(tep); + + printf ("%s kernel is used to generate the tracing data.\n", + old?"Old":"New"); + printf("The size of a long integer is %d bytes.\n", longsize); + printf("The timestamps size is %d bytes.\n", timesize); +... +-- + +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 -- 2.20.1