From patchwork Wed Jun 1 11:18:57 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chunyan Zhang X-Patchwork-Id: 9147201 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 0C31B607D8 for ; Wed, 1 Jun 2016 11:21:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F1EF2269CB for ; Wed, 1 Jun 2016 11:21:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E3F572699B; Wed, 1 Jun 2016 11:21:32 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED, T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 9B0E526785 for ; Wed, 1 Jun 2016 11:21:32 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1b84Bp-0008Jl-IK; Wed, 01 Jun 2016 11:19:57 +0000 Received: from mail-pf0-x231.google.com ([2607:f8b0:400e:c00::231]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1b84Bj-0008B2-Mn for linux-arm-kernel@lists.infradead.org; Wed, 01 Jun 2016 11:19:52 +0000 Received: by mail-pf0-x231.google.com with SMTP id g64so13591029pfb.2 for ; Wed, 01 Jun 2016 04:19:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=tbrGfOaFH1xzms0MDTT7EirEaF0cgvn8PBQ9mFoQqt8=; b=Qi9MECe2sOwv5v04gE+DVwYVPQG44n7P/aYO6qwgQM1bsX7F3QX/YYUAI8u+HrPSR2 U9EXfgbJh4AxFmvuXOlPcOMH3t/3QQnn/eeeual4qudoSs12EoxbyYZEZBiFZoDdirLW 9nkRMBzpGHnELMyyiXDSZ+EOsifenMOL0LBB8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=tbrGfOaFH1xzms0MDTT7EirEaF0cgvn8PBQ9mFoQqt8=; b=MLNDM+s8fxgpvSKvpiMW79EjNE4PI0mvIdSYpgR8FZzoxfG3XCfQ3xvyym0AOdItkc WnzofwSm5xONHCphPaesH85HHAZWTYQR/G/cjXeYLgwmlqfi7XxqB/HPZVNkty8nqSKy toAMffbr/bM1VQU/ta7WxaAUyWW8SVyDfV97sJuWFkes8kYu0UhzjIQ766JE0gDJttzJ XyHOGbKuL5sTOwkM/nkwR1w82LxF5waaNsifOvpnx742uyNWuGk3S/Zan2rxNj8D1Dvs 5KM8QthfbV4k5xw6NXkvSNNKn7H15iFglIESSliuiOCXi0DgS3EMbW3uD+Cn8LY+J3RE mU2Q== X-Gm-Message-State: ALyK8tKt07SjVTY1nB391SCkfzWmByc5py2yLdmJlgqB6kwc60H9lIx3GLyLjKEa79+RenWq X-Received: by 10.98.103.220 with SMTP id t89mr7443905pfj.125.1464779970553; Wed, 01 Jun 2016 04:19:30 -0700 (PDT) Received: from zcy-ubuntu.spreadtrum.com ([175.111.195.49]) by smtp.gmail.com with ESMTPSA id o64sm13254234pfb.76.2016.06.01.04.19.26 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 01 Jun 2016 04:19:29 -0700 (PDT) From: Chunyan Zhang To: rostedt@goodmis.org, mathieu.poirier@linaro.org, alexander.shishkin@linux.intel.com, mingo@redhat.com Subject: [RFC PATCH 2/4] trace: Introduce an output interface from ftrace to STM Date: Wed, 1 Jun 2016 19:18:57 +0800 Message-Id: <1464779939-24986-3-git-send-email-zhang.chunyan@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1464779939-24986-1-git-send-email-zhang.chunyan@linaro.org> References: <1464779939-24986-1-git-send-email-zhang.chunyan@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160601_041951_801027_4FACDE9E X-CRM114-Status: GOOD ( 18.59 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: zhang.lyra@gmail.com, linux-kernel@vger.kernel.org, tor@ti.com, philippe.langlais@st.com, mike.leach@arm.com, nicolas.guion@st.com, linux-arm-kernel@lists.infradead.org, maxime.coquelin@st.com MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP This patch is introducing a new function to print Ftrace messages to STM buffer when the traces happen. In order to reduce the effect on timing overhead as much as possible, only the current function and its parent ip address will be recorded into STM in this patch. This idea was first introduced by Philippe Langlais at ST-Microelectronics a long time ago[1]. [1] http://thread.gmane.org/gmane.linux.kernel/1114274/focus=1114275 Signed-off-by: Chunyan Zhang --- kernel/trace/Makefile | 1 + kernel/trace/trace_output_stm.c | 27 +++++++++++++++++++++++++++ kernel/trace/trace_output_stm.h | 14 ++++++++++++++ 3 files changed, 42 insertions(+) create mode 100644 kernel/trace/trace_output_stm.c create mode 100644 kernel/trace/trace_output_stm.h diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 979e7bf..445afa8 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -69,4 +69,5 @@ obj-$(CONFIG_UPROBE_EVENT) += trace_uprobe.o obj-$(CONFIG_TRACEPOINT_BENCHMARK) += trace_benchmark.o +obj-$(CONFIG_STM_FTRACE) += trace_output_stm.o libftrace-y := ftrace.o diff --git a/kernel/trace/trace_output_stm.c b/kernel/trace/trace_output_stm.c new file mode 100644 index 0000000..f6a3c01 --- /dev/null +++ b/kernel/trace/trace_output_stm.c @@ -0,0 +1,27 @@ +/* + * Output interface from Ftrace to STM buffer + * Copyright (c) 2016, Linaro Ltd. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + */ + +#include "trace_output_stm.h" + +/* Offset above the start channel number */ +#define STM_FTRACE_CHAN 0 + +void ftrace_stm_func(unsigned long ip, unsigned long parent_ip) +{ + unsigned long ip_array[2] = {ip, parent_ip}; + + stm_ftrace_write((char *)ip_array, sizeof(unsigned long) * 2, + STM_FTRACE_CHAN); +} +EXPORT_SYMBOL_GPL(ftrace_stm_func); diff --git a/kernel/trace/trace_output_stm.h b/kernel/trace/trace_output_stm.h new file mode 100644 index 0000000..fc3f989 --- /dev/null +++ b/kernel/trace/trace_output_stm.h @@ -0,0 +1,14 @@ +#ifndef __TRACE_OUTPUT_STM_H +#define __TRACE_OUTPUT_STM_H + +#include + +#ifdef CONFIG_STM_FTRACE +extern void stm_ftrace_write(const char *buf, unsigned int len, + unsigned int chan); +extern void ftrace_stm_func(unsigned long ip, unsigned long parent_ip); +#else +static inline void ftrace_stm_func(unsigned long ip, unsigned long parent_ip) {} +#endif + +#endif /* __TRACE_OUTPUT_STM_H */