Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753520AbdCTJRx (ORCPT ); Mon, 20 Mar 2017 05:17:53 -0400 Received: from mail-it0-f66.google.com ([209.85.214.66]:35684 "EHLO mail-it0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753304AbdCTJRS (ORCPT ); Mon, 20 Mar 2017 05:17:18 -0400 MIME-Version: 1.0 In-Reply-To: <1489992438-14228-1-git-send-email-chunyan.zhang@spreadtrum.com> References: <1489992438-14228-1-git-send-email-chunyan.zhang@spreadtrum.com> From: Alexander Shishkin Date: Mon, 20 Mar 2017 10:49:37 +0200 X-Google-Sender-Auth: aCnuGx7PR1GNxIN2YhbZagW9_DI Message-ID: Subject: Re: [PATCH] stm class: Document the stm_ftrace To: Chunyan Zhang Cc: Alexander Shishkin , linux-doc@vger.kernel.org, Linux Kernel Mailing List , zhang.lyra@gmail.com Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1940 Lines: 49 Hi Chunyan, A couple of clarifications: iirc this applies to the function tracer of ftrace, right? Does it make sense to mention that? Also, are you planning to support other ftrace payloads like trace_printk()s? Thanks, -- Alex On 20 March 2017 at 08:47, Chunyan Zhang wrote: > This patch adds a description of the stm_ftrace device source, an > interface for collecting Function trace information via STM devices. > > Signed-off-by: Chunyan Zhang > --- > Documentation/trace/stm.txt | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/Documentation/trace/stm.txt b/Documentation/trace/stm.txt > index 11cff47..7ec1c0e 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 +107,13 @@ 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 is linked with > +an stm device, 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. > + > [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 > -- > 2.7.4 >