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[2001:1868:205::9]) by mx.google.com with ESMTPS id s13si5998880pag.207.2016.06.21.19.49.09 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 21 Jun 2016 19:49:09 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org designates 2001:1868:205::9 as permitted sender) client-ip=2001:1868:205::9; Authentication-Results: mx.google.com; dkim=neutral (body hash did not verify) header.i=@linaro.org; spf=pass (google.com: best guess record for domain of linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org designates 2001:1868:205::9 as permitted sender) smtp.mailfrom=linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org; dmarc=fail (p=NONE dis=NONE) header.from=linaro.org Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bFYDB-0002d7-LM; Wed, 22 Jun 2016 02:48:17 +0000 Received: from mail-pa0-x22c.google.com ([2607:f8b0:400e:c03::22c]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bFYD9-0002Tq-1D for linux-arm-kernel@lists.infradead.org; Wed, 22 Jun 2016 02:48:15 +0000 Received: by mail-pa0-x22c.google.com with SMTP id bz2so12012111pad.1 for ; Tue, 21 Jun 2016 19:47:54 -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=F4HWFejdh/Ugl98i8FXih7FsxA2PEzroOAPk5JwklIU=; b=HVAHKNdOrDe6GTrlca248gRRsXwQdOv7rHKMK4GBKHqV8zo2NLvxUcqYOrRmtWXfdq HDoSzY1BUg+zjykQr61q07QZSTDjrMv3UG+EXt258jZL9VhZD8X8e2l4cX+tY2AH2TVu yvwTiNUyzUzxA1MA4VZarTAaA0k8QK4e3Q+fk= 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=F4HWFejdh/Ugl98i8FXih7FsxA2PEzroOAPk5JwklIU=; b=eJt1ykbqqUugoxjw6fFlyc7CW+KhAClzj4lNO5jLaUZZ1uxtP2LSSmcS7vLMX8uYqO oSkLPg+LCwtoHXW/eLs7CkMh7soTuwmPa/IqO2tCOhgjbU8CMTWlEEm5WtIoq4X8AQFC 3QpPaS/WHzgNzQ3dh0CtoE1Ne6dMqO8lYuFnZwlDGYmuWlTqVaxlvvQtBFp+VUspDZqi d+hQTnHarTl7u1g5LVFm3EOXmFanKWPcJZXQnhNhAxJkg+VnbKVtkn+rc7qOitfnBuiL WN/5jXy6eU0lLFdXVl3IEsVdSTMFNzIdnsqq+EeYPv7gGU8Mh8rAkx+g0gty7mvpHL0H vJmA== X-Gm-Message-State: ALyK8tIrLeKje5FvKoLkszelkE29/pljrmAzXT6quxcGWnx1wtiZUeB3f8VdO+MbrvjdEzea X-Received: by 10.66.168.13 with SMTP id zs13mr31498215pab.68.1466563674289; Tue, 21 Jun 2016 19:47:54 -0700 (PDT) Received: from zcy-ubuntu.spreadtrum.com ([175.111.195.49]) by smtp.gmail.com with ESMTPSA id y70sm98867836pff.25.2016.06.21.19.47.49 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 21 Jun 2016 19:47:53 -0700 (PDT) From: Chunyan Zhang To: rostedt@goodmis.org, mathieu.poirier@linaro.org, alexander.shishkin@linux.intel.com, mingo@redhat.com Subject: [PATCH V2 1/4] trace: Introduce an output interface from ftrace to STM Date: Wed, 22 Jun 2016 10:46:50 +0800 Message-Id: <1466563613-31578-2-git-send-email-zhang.chunyan@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1466563613-31578-1-git-send-email-zhang.chunyan@linaro.org> References: <1466563613-31578-1-git-send-email-zhang.chunyan@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160621_194815_104676_D42D34E6 X-CRM114-Status: GOOD ( 19.28 ) X-Spam-Score: -2.7 (--) X-Spam-Report: SpamAssassin version 3.4.0 on bombadil.infradead.org summary: Content analysis details: (-2.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [2607:f8b0:400e:c03:0:0:0:22c listed in] [list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid 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+patch=linaro.org@lists.infradead.org This patch is introducing a new output 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's instruction pointer will be recorded into STM. 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 --- include/linux/stm.h | 7 +++++++ include/linux/trace_output_stm.h | 17 +++++++++++++++++ kernel/trace/Makefile | 1 + kernel/trace/trace_output_stm.c | 41 ++++++++++++++++++++++++++++++++++++++++ 4 files changed, 66 insertions(+) create mode 100644 include/linux/trace_output_stm.h create mode 100644 kernel/trace/trace_output_stm.c -- 1.9.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel diff --git a/include/linux/stm.h b/include/linux/stm.h index 8369d8a..2b6639a 100644 --- a/include/linux/stm.h +++ b/include/linux/stm.h @@ -129,6 +129,13 @@ struct stm_source_data { void (*unlink)(struct stm_source_data *data); }; +struct stm_ftrace { + struct stm_source_data data; + void (*write)(struct stm_source_data *data, const char *buf, + unsigned int len, unsigned int chan); + bool available; +}; + int stm_source_register_device(struct device *parent, struct stm_source_data *data); void stm_source_unregister_device(struct stm_source_data *data); diff --git a/include/linux/trace_output_stm.h b/include/linux/trace_output_stm.h new file mode 100644 index 0000000..7edc680 --- /dev/null +++ b/include/linux/trace_output_stm.h @@ -0,0 +1,17 @@ +#ifndef __TRACE_OUTPUT_STM_H +#define __TRACE_OUTPUT_STM_H + +#include + +#if IS_ENABLED(CONFIG_STM_SOURCE_FTRACE) +struct stm_ftrace; +extern void +trace_func_to_stm(unsigned long ip, unsigned long parent_ip); +extern void trace_add_output(struct stm_ftrace *stm); +extern void trace_rm_output(void); +#else +static inline void +trace_func_to_stm(unsigned long ip, unsigned long parent_ip) {} +#endif + +#endif /* __TRACE_OUTPUT_STM_H */ diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 979e7bf..5330803 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_TRACING) += 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..dc04952 --- /dev/null +++ b/kernel/trace/trace_output_stm.c @@ -0,0 +1,41 @@ +/* + * 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 + +/* Offset above the start channel number */ +#define STM_FTRACE_CHAN 0 + +static struct stm_ftrace *trace_output; + +void trace_func_to_stm(unsigned long ip, unsigned long parent_ip) +{ + unsigned long ip_array[2] = {ip, parent_ip}; + + if (trace_output) + trace_output->write(&trace_output->data, (char *)ip_array, + sizeof(unsigned long) * 2, STM_FTRACE_CHAN); +} + +void trace_add_output(struct stm_ftrace *stm) +{ + trace_output = stm; +} +EXPORT_SYMBOL_GPL(trace_add_output); + +void trace_rm_output(void) +{ + trace_output = NULL; +} +EXPORT_SYMBOL_GPL(trace_rm_output);