From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934421AbdHYQYy (ORCPT ); Fri, 25 Aug 2017 12:24:54 -0400 Received: from mga03.intel.com ([134.134.136.65]:41086 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934196AbdHYQYx (ORCPT ); Fri, 25 Aug 2017 12:24:53 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.41,426,1498546800"; d="scan'208";a="894088691" From: Alexander Shishkin To: Greg KH Cc: Mathieu Poirier , Chunyan Zhang , linux-kernel@vger.kernel.org, Chunyan Zhang , Alexander Shishkin Subject: [GIT PULL 02/15] stm class: Document the stm_ftrace Date: Fri, 25 Aug 2017 19:15:53 +0300 Message-Id: <20170825161606.2670-3-alexander.shishkin@linux.intel.com> X-Mailer: git-send-email 2.13.1 In-Reply-To: <20170825161606.2670-1-alexander.shishkin@linux.intel.com> References: <20170825161606.2670-1-alexander.shishkin@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Chunyan Zhang This patch adds a description to the stm_ftrace device source, an interface for collecting Ftrace's function trace information via STM devices. Signed-off-by: Chunyan Zhang Signed-off-by: Alexander Shishkin --- Documentation/trace/stm.txt | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/Documentation/trace/stm.txt b/Documentation/trace/stm.txt index 11cff47eec..0376575010 100644 --- a/Documentation/trace/stm.txt +++ b/Documentation/trace/stm.txt @@ -83,7 +83,7 @@ by writing the name of the desired stm device there, for example: $ echo dummy_stm.0 > /sys/class/stm_source/console/stm_source_link For examples on how to use stm_source interface in the kernel, refer -to stm_console or stm_heartbeat drivers. +to stm_console, stm_heartbeat or stm_ftrace drivers. Each stm_source device will need to assume a master and a range of channels, depending on how many channels it requires. These are @@ -107,5 +107,16 @@ console in the STP stream, create a "console" policy entry (see the beginning of this text on how to do that). When initialized, it will consume one channel. +stm_ftrace +========== + +This is another "stm_source" device, once the stm_ftrace has been +linked with an stm device, and if "function" tracer is enabled, +function address and parent function address which Ftrace subsystem +would store into ring buffer will be exported via the stm device at +the same time. + +Currently only Ftrace "function" tracer is supported. + [1] https://software.intel.com/sites/default/files/managed/d3/3c/intel-th-developer-manual.pdf [2] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0444b/index.html -- 2.14.1