From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751633AbdFIPHV (ORCPT ); Fri, 9 Jun 2017 11:07:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:52694 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751558AbdFIPHU (ORCPT ); Fri, 9 Jun 2017 11:07:20 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BA45A214E1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=rostedt@goodmis.org Date: Fri, 9 Jun 2017 11:07:17 -0400 From: Steven Rostedt To: Felipe Balbi Cc: Alexander Shishkin , Ingo Molnar , Linux USB , linux-kernel@vger.kernel.org, Chunyan Zhang Subject: Re: [PATCH] usb: gadget: functions: add ftrace export over USB Message-ID: <20170609110717.3304f6b9@gandalf.local.home> In-Reply-To: <878tl1qmrj.fsf@linux.intel.com> References: <20170609061327.17899-1-felipe.balbi@linux.intel.com> <20170609100233.414b4b38@gandalf.local.home> <878tl1qmrj.fsf@linux.intel.com> X-Mailer: Claws Mail 3.14.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 09 Jun 2017 17:05:52 +0300 Felipe Balbi wrote: > Hi, > > Steven Rostedt writes: > > On Fri, 9 Jun 2017 09:13:27 +0300 > > Felipe Balbi wrote: > > > >> Allow for ftrace data to be exported over a USB Gadget > >> Controller. With this, we have a potentially very fast pipe for > >> transmitting ftrace data to a Host PC for further analysis. > >> > >> Note that in order to decode the data, one needs access to kernel > >> symbols in order to convert binary data into function names and what > >> not. > >> > > > > Can you please explain what this is in a bit more detail. I have no > > idea what you are trying to accomplish. > > this is just another ftrace export. Just like STM > (drivers/hwtracing/stm/ftrace.c), but I'm making use of a USB Peripheral > Controller that may be available. > > > Also, do you mean ftrace as the internal Linux tracer (which should > > only be called "ftrace" or sometimes "Ftrace" but not "f_trace" or > > "FTrace", that just leads to more confusion. > > heh, internal linux ftrace ;-) The driver name (f-trace.c) is just to > follow the convention of USB functions being name f_*.c or f-*.c. I > could call it f-ftrace.c, but seemed unnecessary. OK, looking at the other files and functions in drivers/usb/gadget/function, I see that F there is part of usb process. OK, although it does make it somewhat confusing. -- Steve