From 18dc49d04588570b37eb4a47c0265a92bec3349b Mon Sep 17 00:00:00 2001
From: Daniele Cattaneo <daniele3.cattaneo@mail.polimi.it>
Date: Sun, 5 Mar 2023 21:41:30 +0100
Subject: [PATCH] Add support for keeping track of cumulative CPU time for each
thread.
Signed-off-by: Terraneo Federico <fede.tft@miosix.org>
---
miosix/Makefile | 1 +
miosix/_doc/doxygen/Doxyfile | 1 +
miosix/config/miosix_settings.h | 6 +
miosix/kernel/cpu_time_counter.cpp | 59 ++++++
miosix/kernel/cpu_time_counter.h | 221 +++++++++++++++++++++++
miosix/kernel/cpu_time_counter_private.h | 56 ++++++
miosix/kernel/cpu_time_counter_types.h | 57 ++++++
miosix/kernel/kernel.h | 8 +
miosix/kernel/scheduler/scheduler.h | 23 ++-
miosix/miosix.h | 1 +
10 files changed, 431 insertions(+), 2 deletions(-)
create mode 100644 miosix/kernel/cpu_time_counter.cpp
create mode 100644 miosix/kernel/cpu_time_counter.h
create mode 100644 miosix/kernel/cpu_time_counter_private.h
create mode 100644 miosix/kernel/cpu_time_counter_types.h
diff --git a/miosix/Makefile b/miosix/Makefile
index 1fb69bf3..07a6266b 100644
--- a/miosix/Makefile
+++ b/miosix/Makefile
@@ -20,6 +20,7 @@ kernel/process.cpp \
kernel/process_pool.cpp \
kernel/timeconversion.cpp \
kernel/SystemMap.cpp \
+kernel/cpu_time_counter.cpp \
kernel/scheduler/priority/priority_scheduler.cpp \
kernel/scheduler/control/control_scheduler.cpp \
kernel/scheduler/edf/edf_scheduler.cpp \
diff --git a/miosix/_doc/doxygen/Doxyfile b/miosix/_doc/doxygen/Doxyfile
index 3d07497c..4272f67c 100644
--- a/miosix/_doc/doxygen/Doxyfile
+++ b/miosix/_doc/doxygen/Doxyfile
@@ -2024,6 +2024,7 @@ INCLUDE_FILE_PATTERNS =
# This tag requires that the tag ENABLE_PREPROCESSING is set to YES.
PREDEFINED = WITH_FILESYSTEM \
+ WITH_CPU_TIME_COUNTER \
_MIOSIX \
MIOSIX_LITTLE_ENDIAN \
__DOXYGEN__
diff --git a/miosix/config/miosix_settings.h b/miosix/config/miosix_settings.h
index a5a3d675..a1c33bb3 100644
--- a/miosix/config/miosix_settings.h
+++ b/miosix/config/miosix_settings.h
@@ -76,6 +76,12 @@ namespace miosix {
//#define SCHED_TYPE_CONTROL_BASED
//#define SCHED_TYPE_EDF
+/// \def WITH_CPU_TIME_COUNTER
+/// Allows to enable/disable CPUTimeCounter to save code size and remove its
+/// overhead from the scheduling process. By default it is defined
+/// (CPUTimeCounter is enabled).
+#define WITH_CPU_TIME_COUNTER
+
//
// Filesystem options
//
diff --git a/miosix/kernel/cpu_time_counter.cpp b/miosix/kernel/cpu_time_counter.cpp
new file mode 100644
index 00000000..ea57ed48
--- /dev/null
+++ b/miosix/kernel/cpu_time_counter.cpp
@@ -0,0 +1,59 @@
+/***************************************************************************
+ * Copyright (C) 2023 by Daniele Cattaneo *
+ * *
+ * This program is free software; you can redistribute it and/or modify *
+ * it under the terms of the GNU General Public License as published by *
+ * the Free Software Foundation; either version 2 of the License, or *
+ * (at your option) any later version. *
+ * *
+ * This program is distributed in the hope that 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. *
+ * *
+ * As a special exception, if other files instantiate templates or use *
+ * macros or inline functions from this file, or you compile this file *
+ * and link it with other works to produce a work based on this file, *
+ * this file does not by itself cause the resulting work to be covered *
+ * by the GNU General Public License. However the source code for this *
+ * file must still be made available in accordance with the GNU General *
+ * Public License. This exception does not invalidate any other reasons *
+ * why a work based on this file might be covered by the GNU General *
+ * Public License. *
+ * *
+ * You should have received a copy of the GNU General Public License *
+ * along with this program; if not, see <http://www.gnu.org/licenses/> *
+ ***************************************************************************/
+
+#include "cpu_time_counter.h"
+#include "kernel/kernel.h"
+
+#ifdef WITH_CPU_TIME_COUNTER
+
+using namespace miosix;
+
+Thread *CPUTimeCounter::head = nullptr;
+Thread *CPUTimeCounter::tail = nullptr;
+volatile unsigned int CPUTimeCounter::nThreads = 0;
+
+void CPUTimeCounter::PKremoveDeadThreads()
+{
+ Thread *prev = nullptr;
+ Thread *cur = head;
+ while (cur) {
+ if (cur->flags.isDeleted()) {
+ if (prev) {
+ prev->timeCounterData.next = cur->timeCounterData.next;
+ } else {
+ head = cur->timeCounterData.next;
+ }
+ nThreads--;
+ } else {
+ prev = cur;
+ }
+ cur = cur->timeCounterData.next;
+ }
+ tail = prev;
+}
+
+#endif // WITH_CPU_TIME_COUNTER
diff --git a/miosix/kernel/cpu_time_counter.h b/miosix/kernel/cpu_time_counter.h
new file mode 100644
index 00000000..d9e0f998
--- /dev/null
+++ b/miosix/kernel/cpu_time_counter.h
@@ -0,0 +1,221 @@
+/***************************************************************************
+ * Copyright (C) 2023 by Daniele Cattaneo *
+ * *
+ * This program is free software; you can redistribute it and/or modify *
+ * it under the terms of the GNU General Public License as published by *
+ * the Free Software Foundation; either version 2 of the License, or *
+ * (at your option) any later version. *
+ * *
+ * This program is distributed in the hope that 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. *
+ * *
+ * As a special exception, if other files instantiate templates or use *
+ * macros or inline functions from this file, or you compile this file *
+ * and link it with other works to produce a work based on this file, *
+ * this file does not by itself cause the resulting work to be covered *
+ * by the GNU General Public License. However the source code for this *
+ * file must still be made available in accordance with the GNU General *
+ * Public License. This exception does not invalidate any other reasons *
+ * why a work based on this file might be covered by the GNU General *
+ * Public License. *
+ * *
+ * You should have received a copy of the GNU General Public License *
+ * along with this program; if not, see <http://www.gnu.org/licenses/> *
+ ***************************************************************************/
+
+#ifndef CPU_TIME_COUNTER_H
+#define CPU_TIME_COUNTER_H
+
+#include "kernel.h"
+#include "cpu_time_counter_types.h"
+
+#ifdef WITH_CPU_TIME_COUNTER
+
+namespace miosix {
+
+/**
+ * \addtogroup Kernel
+ * \{
+ */
+
+/**
+ * CPUTimeCounter provides a low-level method to retrieve information about how
+ * much CPU time was used up to now by each thread in the system.
+ * It is intended for debugging and evaluation purposes and is enabled only if
+ * the symbol `WITH_CPU_TIME_COUNTER` has been defined in
+ * config/miosix_settings.h.
+ *
+ * The implementation of this class collects this data by intercepting context
+ * switch events. Due to the measurement method, some caveats apply to the data
+ * returned:
+ * - There is no distinction between time spent in thread code or in the
+ * kernel.
+ * - Time spent in an interrupt is accounted towards the thread that has been
+ * interrupted.
+ *
+ * Retrieving the time accounting data for all threads is performed through the
+ * iterator returned by PKbegin(). To prevent the thread list from changing
+ * because of a context switch, keep the kernel paused while you traverse the
+ * iterator.
+ *
+ * To simplify post-processing, the list of thread data information accessible
+ * through the iterator always satisfies the following properties:
+ * - There is at least one item in the list.
+ * - The first item corresponds to the idle thread.
+ * - The threads are listed in creation order.
+ * - The relative order in which the items are iterated is deterministic and
+ * does not change even after a context switch.
+ *
+ * These properties allow to compute the difference between two thread data
+ * lists collected at different times in O(max(n,m)) complexity.
+ *
+ * \note This is a very low-level interface. For actual use, a more practical
+ * alternative is miosix::CPUProfiler, which provides a top-like display of the
+ * amount of CPU used by each thread in a given time interval.
+ */
+class CPUTimeCounter
+{
+public:
+ /**
+ * Struct used to return the time counter data for a specific thread.
+ */
+ struct Data
+ {
+ /// The thread the data belongs to
+ Thread *thread;
+ /// Cumulative amount of CPU time scheduled to the thread in ns
+ long long usedCpuTime = 0;
+ };
+
+ /**
+ * CPUTimeCounter thread data iterator type
+ */
+ class iterator
+ {
+ public:
+ inline iterator operator++()
+ {
+ cur = cur->timeCounterData.next;
+ return *this;
+ }
+ inline iterator operator++(int)
+ {
+ iterator result = *this;
+ cur = cur->timeCounterData.next;
+ return result;
+ }
+ inline Data operator*()
+ {
+ Data res;
+ res.thread = cur;
+ res.usedCpuTime = cur->timeCounterData.usedCpuTime;
+ return res;
+ }
+ inline bool operator==(const iterator& rhs) { return cur==rhs.cur; }
+ inline bool operator!=(const iterator& rhs) { return cur!=rhs.cur; }
+ private:
+ friend class CPUTimeCounter;
+ Thread *cur;
+ iterator(Thread *cur) : cur(cur) {}
+ };
+
+ /**
+ * \returns the number of threads currently alive in the system.
+ * \warning This method is only provided for the purpose of reserving enough
+ * memory for collecting the time data for all threads. The value it
+ * returns may change at any time.
+ */
+ static inline unsigned int getThreadCount()
+ {
+ return nThreads;
+ }
+
+ /**
+ * \returns the begin iterator for the thread data.
+ */
+ static iterator PKbegin()
+ {
+ return iterator(head);
+ }
+
+ /**
+ * \returns the end iterator for the thread data.
+ */
+ static iterator PKend()
+ {
+ return iterator(nullptr);
+ }
+
+private:
+ // The following methods are called from basic_scheduler to notify
+ // CPUTimeCounter of various events.
+ template<typename> friend class basic_scheduler;
+
+ // CPUTimeCounter cannot be constructed
+ CPUTimeCounter() = delete;
+
+ /**
+ * \internal
+ * Add the idle thread to the list of threads tracked by CPUTimeCounter.
+ * \param thread The idle thread.
+ */
+ static inline void PKaddIdleThread(Thread *thread)
+ {
+ thread->timeCounterData.next = head;
+ head = thread;
+ if (!tail)
+ tail = thread;
+ nThreads++;
+ }
+
+ /**
+ * \internal
+ * Add an item to the list of threads tracked by CPUTimeCounter.
+ * \param thread The thread to be added.
+ */
+ static inline void PKaddThread(Thread *thread)
+ {
+ tail->timeCounterData.next = thread;
+ tail = thread;
+ if (!head)
+ head = thread;
+ nThreads++;
+ }
+
+ /**
+ * \internal
+ * Update the list of threads tracked by CPUTimeCounter to remove dead
+ * threads.
+ */
+ static void PKremoveDeadThreads();
+
+ /**
+ * \internal
+ * Notify that a context switch is about to happen.
+ * \returns The current time.
+ */
+ static inline long long PKwillSwitchContext();
+
+ /**
+ * \internal
+ * Notify that a context switch has just happened.
+ * \param t The time of the context switch.
+ */
+ static inline void PKdidSwitchContext(long long t);
+
+ static Thread *head; ///< Head of the thread list
+ static Thread *tail; ///< Tail of the thread list
+ static volatile unsigned int nThreads; ///< Number of threads in the list
+};
+
+/**
+ * \}
+ */
+
+}
+
+#endif // WITH_CPU_TIME_COUNTER
+
+#endif
diff --git a/miosix/kernel/cpu_time_counter_private.h b/miosix/kernel/cpu_time_counter_private.h
new file mode 100644
index 00000000..734308e7
--- /dev/null
+++ b/miosix/kernel/cpu_time_counter_private.h
@@ -0,0 +1,56 @@
+/***************************************************************************
+ * Copyright (C) 2023 by Daniele Cattaneo *
+ * *
+ * This program is free software; you can redistribute it and/or modify *
+ * it under the terms of the GNU General Public License as published by *
+ * the Free Software Foundation; either version 2 of the License, or *
+ * (at your option) any later version. *
+ * *
+ * This program is distributed in the hope that 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. *
+ * *
+ * As a special exception, if other files instantiate templates or use *
+ * macros or inline functions from this file, or you compile this file *
+ * and link it with other works to produce a work based on this file, *
+ * this file does not by itself cause the resulting work to be covered *
+ * by the GNU General Public License. However the source code for this *
+ * file must still be made available in accordance with the GNU General *
+ * Public License. This exception does not invalidate any other reasons *
+ * why a work based on this file might be covered by the GNU General *
+ * Public License. *
+ * *
+ * You should have received a copy of the GNU General Public License *
+ * along with this program; if not, see <http://www.gnu.org/licenses/> *
+ ***************************************************************************/
+
+#ifndef CPU_TIME_COUNTER_PRIVATE_H
+#define CPU_TIME_COUNTER_PRIVATE_H
+
+#include "cpu_time_counter.h"
+
+#ifdef WITH_CPU_TIME_COUNTER
+
+namespace miosix {
+
+// Declared in kernel.cpp
+extern volatile Thread *cur;
+
+long long CPUTimeCounter::PKwillSwitchContext()
+{
+ long long t = IRQgetTime();
+ cur->timeCounterData.usedCpuTime += t - cur->timeCounterData.lastActivation;
+ return t;
+}
+
+void CPUTimeCounter::PKdidSwitchContext(long long t)
+{
+ cur->timeCounterData.lastActivation = t;
+}
+
+}
+
+#endif // WITH_CPU_TIME_COUNTER
+
+#endif
diff --git a/miosix/kernel/cpu_time_counter_types.h b/miosix/kernel/cpu_time_counter_types.h
new file mode 100644
index 00000000..e897667b
--- /dev/null
+++ b/miosix/kernel/cpu_time_counter_types.h
@@ -0,0 +1,57 @@
+/***************************************************************************
+ * Copyright (C) 2023 by Daniele Cattaneo *
+ * *
+ * This program is free software; you can redistribute it and/or modify *
+ * it under the terms of the GNU General Public License as published by *
+ * the Free Software Foundation; either version 2 of the License, or *
+ * (at your option) any later version. *
+ * *
+ * This program is distributed in the hope that 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. *
+ * *
+ * As a special exception, if other files instantiate templates or use *
+ * macros or inline functions from this file, or you compile this file *
+ * and link it with other works to produce a work based on this file, *
+ * this file does not by itself cause the resulting work to be covered *
+ * by the GNU General Public License. However the source code for this *
+ * file must still be made available in accordance with the GNU General *
+ * Public License. This exception does not invalidate any other reasons *
+ * why a work based on this file might be covered by the GNU General *
+ * Public License. *
+ * *
+ * You should have received a copy of the GNU General Public License *
+ * along with this program; if not, see <http://www.gnu.org/licenses/> *
+ ***************************************************************************/
+
+#ifndef CPU_TIME_COUNTER_TYPES_H
+#define CPU_TIME_COUNTER_TYPES_H
+
+#include "config/miosix_settings.h"
+
+#ifdef WITH_CPU_TIME_COUNTER
+
+namespace miosix {
+
+class Thread;
+
+/**
+ * \internal
+ * Thread-local data structure used by the implementation of CPUTimeCounter
+ */
+struct CPUTimeCounterPrivateThreadData
+{
+ /// Timestamp of the last context change to this thread
+ long long lastActivation = 0;
+ /// Cumulative amount of CPU time used by this thread
+ long long usedCpuTime = 0;
+ /// Next thread in the thread list used by CPUTimeCounter
+ Thread *next = nullptr;
+};
+
+}
+
+#endif // WITH_CPU_TIME_COUNTER
+
+#endif
diff --git a/miosix/kernel/kernel.h b/miosix/kernel/kernel.h
index 9c80f856..58ece03c 100755
--- a/miosix/kernel/kernel.h
+++ b/miosix/kernel/kernel.h
@@ -32,6 +32,7 @@
#include "kernel/scheduler/sched_types.h"
#include "stdlib_integration/libstdcpp_integration.h"
#include "intrusive.h"
+#include "cpu_time_counter_types.h"
#include <cstdlib>
#include <new>
#include <functional>
@@ -1025,6 +1026,9 @@ private:
///pointer is null
unsigned int *userCtxsave;
#endif //WITH_PROCESSES
+ #ifdef WITH_CPU_TIME_COUNTER
+ CPUTimeCounterPrivateThreadData timeCounterData;
+ #endif //WITH_CPU_TIME_COUNTER
//friend functions
//Needs access to watermark, ctxsave
@@ -1062,6 +1066,10 @@ private:
//Needs PKcreateUserspace(), setupUserspaceContext(), switchToUserspace()
friend class Process;
#endif //WITH_PROCESSES
+ #ifdef WITH_CPU_TIME_COUNTER
+ //Needs access to timeCounterData
+ friend class CPUTimeCounter;
+ #endif //WITH_CPU_TIME_COUNTER
};
/**
diff --git a/miosix/kernel/scheduler/scheduler.h b/miosix/kernel/scheduler/scheduler.h
index cb4043ed..ed67a16c 100755
--- a/miosix/kernel/scheduler/scheduler.h
+++ b/miosix/kernel/scheduler/scheduler.h
@@ -32,6 +32,7 @@
#include "kernel/scheduler/priority/priority_scheduler.h"
#include "kernel/scheduler/control/control_scheduler.h"
#include "kernel/scheduler/edf/edf_scheduler.h"
+#include "kernel/cpu_time_counter_private.h"
namespace miosix {
@@ -67,7 +68,12 @@ public:
*/
static bool PKaddThread(Thread *thread, Priority priority)
{
- return T::PKaddThread(thread,priority);
+ bool res = T::PKaddThread(thread,priority);
+ #ifdef WITH_CPU_TIME_COUNTER
+ if (res)
+ CPUTimeCounter::PKaddThread(thread);
+ #endif
+ return res;
}
/**
@@ -91,6 +97,9 @@ public:
*/
static void PKremoveDeadThreads()
{
+ #ifdef WITH_CPU_TIME_COUNTER
+ CPUTimeCounter::PKremoveDeadThreads();
+ #endif
T::PKremoveDeadThreads();
}
@@ -138,6 +147,9 @@ public:
*/
static void IRQsetIdleThread(Thread *idleThread)
{
+ #ifdef WITH_CPU_TIME_COUNTER
+ CPUTimeCounter::PKaddIdleThread(idleThread);
+ #endif
return T::IRQsetIdleThread(idleThread);
}
@@ -167,7 +179,14 @@ public:
*/
static unsigned int IRQfindNextThread()
{
- return T::IRQfindNextThread();
+ #ifdef WITH_CPU_TIME_COUNTER
+ long long t = CPUTimeCounter::PKwillSwitchContext();
+ #endif
+ unsigned int res = T::IRQfindNextThread();
+ #ifdef WITH_CPU_TIME_COUNTER
+ CPUTimeCounter::PKdidSwitchContext(t);
+ #endif
+ return res;
}
/**
diff --git a/miosix/miosix.h b/miosix/miosix.h
index 8fc8e39a..0a7de362 100644
--- a/miosix/miosix.h
+++ b/miosix/miosix.h
@@ -38,6 +38,7 @@
#include <kernel/kernel.h>
#include <kernel/sync.h>
#include <kernel/queue.h>
+#include <kernel/cpu_time_counter.h>
/* Utilities */
#include <util/util.h>
/* Settings */
--
GitLab