load_mon: increase cpuload update rate, get corresponding time safetly, and misc cleanup

.ci/Jenkinsfile-hardware

@@ -922,6 +922,7 @@ void statusFTDI() {
   sh './Tools/HIL/run_nsh_cmd.py --device `find /dev/serial -name *usb-FTDI_*` --cmd "gps status"'
   sh './Tools/HIL/run_nsh_cmd.py --device `find /dev/serial -name *usb-FTDI_*` --cmd "listener adc_report"'
   sh './Tools/HIL/run_nsh_cmd.py --device `find /dev/serial -name *usb-FTDI_*` --cmd "listener battery_status"'
+  sh './Tools/HIL/run_nsh_cmd.py --device `find /dev/serial -name *usb-FTDI_*` --cmd "listener cpuload"'
   sh './Tools/HIL/run_nsh_cmd.py --device `find /dev/serial -name *usb-FTDI_*` --cmd "listener logger_status"'
   sh './Tools/HIL/run_nsh_cmd.py --device `find /dev/serial -name *usb-FTDI_*` --cmd "listener sensor_accel"'
   sh './Tools/HIL/run_nsh_cmd.py --device `find /dev/serial -name *usb-FTDI_*` --cmd "listener sensor_accel_fifo"'
@@ -985,6 +986,7 @@ void statusSEGGER() {
   sh './Tools/HIL/run_nsh_cmd.py --device `find /dev/serial -name *usb-SEGGER_*` --cmd "gps status"'
   sh './Tools/HIL/run_nsh_cmd.py --device `find /dev/serial -name *usb-SEGGER_*` --cmd "listener adc_report"'
   sh './Tools/HIL/run_nsh_cmd.py --device `find /dev/serial -name *usb-SEGGER_*` --cmd "listener battery_status"'
+  sh './Tools/HIL/run_nsh_cmd.py --device `find /dev/serial -name *usb-SEGGER_*` --cmd "listener cpuload"'
   sh './Tools/HIL/run_nsh_cmd.py --device `find /dev/serial -name *usb-SEGGER_*` --cmd "listener logger_status"'
   sh './Tools/HIL/run_nsh_cmd.py --device `find /dev/serial -name *usb-SEGGER_*` --cmd "listener sensor_accel"'
   sh './Tools/HIL/run_nsh_cmd.py --device `find /dev/serial -name *usb-SEGGER_*` --cmd "listener sensor_accel_fifo"'

src/modules/load_mon/CMakeLists.txt

@@ -1,6 +1,6 @@
 ############################################################################
 #
-#   Copyright (c) 2016 PX4 Development Team. All rights reserved.
+#   Copyright (c) 2016-2020 PX4 Development Team. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -35,8 +35,8 @@ px4_add_module(
 	MAIN load_mon
 	COMPILE_FLAGS
 	SRCS
-		load_mon.cpp
+		LoadMon.cpp
+		LoadMon.hpp
 	DEPENDS
 		px4_work_queue
-	)
-
+)

src/modules/load_mon/LoadMon.cpp

@@ -0,0 +1,227 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2012-2020 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#include "LoadMon.hpp"
+
+// if free stack space falls below this, print a warning
+#if defined(CONFIG_ARMV7M_STACKCHECK)
+static constexpr unsigned STACK_LOW_WARNING_THRESHOLD = 100;
+#else
+static constexpr unsigned STACK_LOW_WARNING_THRESHOLD = 300;
+#endif
+
+static constexpr unsigned FDS_LOW_WARNING_THRESHOLD = 2; ///< if free file descriptors fall below this, print a warning
+
+using namespace time_literals;
+
+namespace load_mon
+{
+
+LoadMon::LoadMon() :
+	ModuleParams(nullptr),
+	ScheduledWorkItem(MODULE_NAME, px4::wq_configurations::lp_default)
+{
+}
+
+LoadMon::~LoadMon()
+{
+	ScheduleClear();
+	perf_free(_cycle_perf);
+}
+
+int LoadMon::task_spawn(int argc, char *argv[])
+{
+	LoadMon *obj = new LoadMon();
+
+	if (!obj) {
+		PX4_ERR("alloc failed");
+		return -1;
+	}
+
+	_object.store(obj);
+	_task_id = task_id_is_work_queue;
+
+	/* Schedule a cycle to start things. */
+	obj->start();
+
+	return 0;
+}
+
+void LoadMon::start()
+{
+	ScheduleOnInterval(300_ms);
+}
+
+void LoadMon::Run()
+{
+	perf_begin(_cycle_perf);
+
+	cpuload();
+
+	if (_param_sys_stck_en.get()) {
+		stack_usage();
+	}
+
+	if (should_exit()) {
+		ScheduleClear();
+		exit_and_cleanup();
+	}
+
+	perf_end(_cycle_perf);
+}
+
+void LoadMon::cpuload()
+{
+	if (_last_idle_time == 0) {
+		// Just get the time in the first iteration */
+		_last_idle_time = system_load.tasks[0].total_runtime;
+		_last_idle_time_sample = hrt_absolute_time();
+		return;
+	}
+
+	irqstate_t irqstate = enter_critical_section();
+	const hrt_abstime now = hrt_absolute_time();
+	const hrt_abstime total_runtime = system_load.tasks[0].total_runtime;
+	leave_critical_section(irqstate);
+
+	// compute system load
+	const float interval = now - _last_idle_time_sample;
+	const float interval_idletime = total_runtime - _last_idle_time;
+
+	// get ram usage
+	struct mallinfo mem = mallinfo();
+	float ram_usage = (float)mem.uordblks / mem.arena;
+
+	cpuload_s cpuload{};
+	cpuload.load = 1.f - interval_idletime / interval;
+	cpuload.ram_usage = ram_usage;
+	cpuload.timestamp = hrt_absolute_time();
+
+	_cpuload_pub.publish(cpuload);
+
+	// store for next iteration
+	_last_idle_time = total_runtime;
+	_last_idle_time_sample = now;
+}
+
+void LoadMon::stack_usage()
+{
+	unsigned stack_free = 0;
+	unsigned fds_free = FDS_LOW_WARNING_THRESHOLD + 1;
+
+	bool checked_task = false;
+
+	task_stack_info_s task_stack_info{};
+	static_assert(sizeof(task_stack_info.task_name) == CONFIG_TASK_NAME_SIZE,
+		      "task_stack_info.task_name must match NuttX CONFIG_TASK_NAME_SIZE");
+
+	sched_lock();
+
+	if (system_load.tasks[_stack_task_index].valid && (system_load.tasks[_stack_task_index].tcb->pid > 0)) {
+
+		stack_free = up_check_tcbstack_remain(system_load.tasks[_stack_task_index].tcb);
+
+		strncpy((char *)task_stack_info.task_name, system_load.tasks[_stack_task_index].tcb->name, CONFIG_TASK_NAME_SIZE - 1);
+		task_stack_info.task_name[CONFIG_TASK_NAME_SIZE - 1] = '\0';
+
+		checked_task = true;
+
+#if CONFIG_NFILE_DESCRIPTORS > 0
+		FAR struct task_group_s *group = system_load.tasks[_stack_task_index].tcb->group;
+
+		unsigned tcb_num_used_fds = 0;
+
+		if (group) {
+			for (int fd_index = 0; fd_index < CONFIG_NFILE_DESCRIPTORS; ++fd_index) {
+				if (group->tg_filelist.fl_files[fd_index].f_inode) {
+					++tcb_num_used_fds;
+				}
+			}
+
+			fds_free = CONFIG_NFILE_DESCRIPTORS - tcb_num_used_fds;
+		}
+
+#endif // CONFIG_NFILE_DESCRIPTORS
+	}
+
+	sched_unlock();
+
+	if (checked_task) {
+		task_stack_info.stack_free = stack_free;
+		task_stack_info.timestamp = hrt_absolute_time();
+
+		_task_stack_info_pub.publish(task_stack_info);
+
+		// Found task low on stack, report and exit. Continue here in next cycle.
+		if (stack_free < STACK_LOW_WARNING_THRESHOLD) {
+			PX4_WARN("%s low on stack! (%i bytes left)", task_stack_info.task_name, stack_free);
+		}
+
+		// Found task low on file descriptors, report and exit. Continue here in next cycle.
+		if (fds_free < FDS_LOW_WARNING_THRESHOLD) {
+			PX4_WARN("%s low on FDs! (%i FDs left)", task_stack_info.task_name, fds_free);
+		}
+	}
+
+	// Continue after last checked task next cycle
+	_stack_task_index = (_stack_task_index + 1) % CONFIG_MAX_TASKS;
+}
+
+int LoadMon::print_usage(const char *reason)
+{
+	if (reason) {
+		PX4_ERR("%s\n", reason);
+	}
+
+	PRINT_MODULE_DESCRIPTION(
+		R"DESCR_STR(
+### Description
+Background process running periodically on the low priority work queue to calculate the CPU load and RAM
+usage and publish the `cpuload` topic.
+
+On NuttX it also checks the stack usage of each process and if it falls below 300 bytes, a warning is output,
+which will also appear in the log file.
+)DESCR_STR");
+
+	PRINT_MODULE_USAGE_NAME("load_mon", "system");
+	PRINT_MODULE_USAGE_COMMAND_DESCR("start", "Start the background task");
+	PRINT_MODULE_USAGE_DEFAULT_COMMANDS();
+	return 0;
+}
+
+extern "C" __EXPORT int load_mon_main(int argc, char *argv[])
+{
+	return LoadMon::main(argc, argv);
+}
+
+} // namespace load_mon

src/modules/load_mon/LoadMon.hpp

@@ -0,0 +1,95 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2012-2020 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#pragma once
+
+#include <drivers/drv_hrt.h>
+#include <lib/perf/perf_counter.h>
+#include <px4_platform_common/px4_config.h>
+#include <px4_platform_common/defines.h>
+#include <px4_platform_common/module.h>
+#include <px4_platform_common/module_params.h>
+#include <px4_platform_common/px4_work_queue/ScheduledWorkItem.hpp>
+#include <systemlib/cpuload.h>
+#include <uORB/Publication.hpp>
+#include <uORB/topics/cpuload.h>
+#include <uORB/topics/task_stack_info.h>
+
+namespace load_mon
+{
+
+class LoadMon : public ModuleBase<LoadMon>, public ModuleParams, public px4::ScheduledWorkItem
+{
+public:
+	LoadMon();
+	~LoadMon() override;
+
+	static int task_spawn(int argc, char *argv[]);
+
+	/** @see ModuleBase */
+	static int custom_command(int argc, char *argv[])
+	{
+		return print_usage("unknown command");
+	}
+
+	/** @see ModuleBase */
+	static int print_usage(const char *reason = nullptr);
+
+	void start();
+
+private:
+	/** Do a compute and schedule the next cycle. */
+	void Run() override;
+
+	/** Do a calculation of the CPU load and publish it. */
+	void cpuload();
+
+	/* Calculate stack usage */
+	void stack_usage();
+
+	int _stack_task_index{0};
+
+	uORB::PublicationQueued<task_stack_info_s> _task_stack_info_pub{ORB_ID(task_stack_info)};
+	uORB::Publication<cpuload_s> _cpuload_pub{ORB_ID(cpuload)};
+
+	hrt_abstime _last_idle_time{0};
+	hrt_abstime _last_idle_time_sample{0};
+
+	perf_counter_t _cycle_perf{perf_alloc(PC_ELAPSED, MODULE_NAME": cycle")};
+
+	DEFINE_PARAMETERS(
+		(ParamBool<px4::params::SYS_STCK_EN>) _param_sys_stck_en
+	)
+};
+
+} // namespace load_mon