Important: Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

QNetworkAccessManager increases CPU and Memory Usage



  • Hai All,

    I am running Qt QML application on embedded device (imx6ull). This device is running with Yocto dunfell version and Qt 15.14.2 version.

    I Just declared the QNetworkAccessManger class in my QML application. This is causing the CPU usage to go high upto 90% as shown in the below Image. When I run it for long duration, gradually the memory is also increasing. Finally the OOM killer is killing the application

    Note: Development OS : Ubuntu 20.04

    fcac77a4-e644-4d28-afcd-9a3993bead48-image.png

    Process containing ID 598 : ACC1120_RAVEN_A is running with 98.8 of CPU usage. when it runs for log duration the memory usage also increases.

    Below is the Code which I am using
    main.cpp

    #include <QGuiApplication>
    #include <QQmlApplicationEngine>
    #include <QNetworkAccessManager>
    
    int main(int argc, char *argv[])
    {
    #if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
        QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
    #endif
        QGuiApplication app(argc, argv);
    
        QNetworkAccessManager manager;
    
        QQmlApplicationEngine engine;
        const QUrl url(QStringLiteral("qrc:/main.qml"));
        QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,
                         &app, [url](QObject *obj, const QUrl &objUrl) {
            if (!obj && url == objUrl)
                QCoreApplication::exit(-1);
        }, Qt::QueuedConnection);
        engine.load(url);
    
        return app.exec();
    }
    
    

    main.qml

    import QtQuick 2.12
    import QtQuick.Window 2.12
    
    Window {
        width: 640
        height: 480
        visible: true
        title: qsTr("Hello World")
    }
    
    

    pro file

    QT += quick
    QT += network
    
    TEMPLATE = app
    TARGET = ACC1120_RAVEN_APPL
    
    # You can make your code fail to compile if it uses deprecated APIs.
    # In order to do so, uncomment the following line.
    #DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0
    
    SOURCES += \
            main.cpp
    
    RESOURCES += qml.qrc
    
    # Default rules for deployment.
    target.path = /home/root
    INSTALLS += target
    
    
    
    

    Looks like there is some bug in the QNetworkAccessManager.
    How can I fix this issue ?

    Regards,
    James A



  • Do you have try to run with gprof? for watch what are using CPU

    And you have try to build a console app with QNetworkAccessManager.



  • @sifourquier

    I tried with console app by running it for 30 seconds. Still I see there is increase in the CPU usage , which went to 98%. From the gprof logs I cloud not make out what is wrong. I updated the code and gprog logs below

    #QT += quick
    QT += network
    #QT += gui
    
    CONFIG += c++11 console
    CONFIG -= app_bundle
    
    #TEMPLATE = app
    TARGET = ACC1120_RAVEN_APPL
    
    CONFIG += debug
    
    # You can make your code fail to compile if it uses deprecated APIs.
    # In order to do so, uncomment the following line.
    #DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0
    
    SOURCES += \
            main.cpp
    
    #RESOURCES += qml.qrc
    
    QMAKE_CXXFLAGS_DEBUG *= -pg
    QMAKE_LFLAGS_DEBUG *= -pg
    
    # Default rules for deployment.
    target.path = /home/root
    INSTALLS += target
    
    

    main.cpp

    
    //#include <QGuiApplication>
    #include <QNetworkAccessManager>
    #include <QTimer>
    #include <QCoreApplication>
    
    int main(int argc, char *argv[])
    {
    //#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
    //    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
    //#endif
    
    //    QGuiApplication a(argc, argv);
    
        QCoreApplication a(argc, argv);
    
        QNetworkAccessManager manager;
    
        QTimer::singleShot(30000,[=](){
            QCoreApplication::quit();
        });
    
        return a.exec();
    }
    
    

    gprof logs

    Flat profile:
    
    Each sample counts as 0.01 seconds.
     no time accumulated
    
      %   cumulative   self              self     total           
     time   seconds   seconds    calls  Ts/call  Ts/call  name    
      0.00      0.00     0.00        3     0.00     0.00  std::remove_reference<main::{lambda()#1}&>::type&& std::move<main::{lambda()#1}&>(std::remove_reference&&)
      0.00      0.00     0.00        1     0.00     0.00  QAtomicInt::QAtomicInt(int)
      0.00      0.00     0.00        1     0.00     0.00  QAtomicInteger<int>::QAtomicInteger(int)
      0.00      0.00     0.00        1     0.00     0.00  QBasicAtomicInteger<int>::QBasicAtomicInteger(int)
      0.00      0.00     0.00        1     0.00     0.00  std::enable_if<(!QtPrivate::FunctionPointer<main::{lambda()#1}>::IsPointerToMemberFunction)&&(!std::is_same<char const*, QtPrivate::FunctionPointer>::value), void>::type QTimer::singleShot<int, main::{lambda()#1}>(int, Qt::TimerType, QObject const*, QtPrivate::FunctionPointer)
      0.00      0.00     0.00        1     0.00     0.00  std::enable_if<(!QtPrivate::FunctionPointer<main::{lambda()#1}>::IsPointerToMemberFunction)&&(!std::is_same<char const*, QtPrivate::FunctionPointer>::value), void>::type QTimer::singleShot<int, main::{lambda()#1}>(int, QtPrivate::FunctionPointer)
      0.00      0.00     0.00        1     0.00     0.00  QTimer::defaultTypeFor(int)
      0.00      0.00     0.00        1     0.00     0.00  QtPrivate::FunctorCall<QtPrivate::IndexesList<>, QtPrivate::List<>, void, main::{lambda()#1}>::call({lambda()#1}&, void**)
      0.00      0.00     0.00        1     0.00     0.00  QtPrivate::QSlotObjectBase::QSlotObjectBase(void (*)(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*))
      0.00      0.00     0.00        1     0.00     0.00  QtPrivate::QSlotObjectBase::~QSlotObjectBase()
      0.00      0.00     0.00        1     0.00     0.00  QtPrivate::ApplyReturnValue<void>::ApplyReturnValue(void*)
      0.00      0.00     0.00        1     0.00     0.00  QtPrivate::QFunctorSlotObject<main::{lambda()#1}, 0, QtPrivate::List<>, void>::QFunctorSlotObject({lambda()#1})
      0.00      0.00     0.00        1     0.00     0.00  QtPrivate::QFunctorSlotObject<main::{lambda()#1}, 0, QtPrivate::List<>, void>::~QFunctorSlotObject()
      0.00      0.00     0.00        1     0.00     0.00  void QtPrivate::Functor<main::{lambda()#1}, 0>::call<QtPrivate::List<>, void>({lambda()#1}&, void*, {lambda()#1}&*)
      0.00      0.00     0.00        1     0.00     0.00  std::__atomic_base<int>::__atomic_base(int)
      0.00      0.00     0.00        1     0.00     0.00  std::atomic<int>::atomic(int)
      0.00      0.00     0.00        1     0.00     0.00  main::{lambda()#1}::operator()() const
    
     %         the percentage of the total running time of the
    time       program used by this function.
    
    cumulative a running sum of the number of seconds accounted
     seconds   for by this function and those listed above it.
    
     self      the number of seconds accounted for by this
    seconds    function alone.  This is the major sort for this
               listing.
    
    calls      the number of times this function was invoked, if
               this function is profiled, else blank.
    
     self      the average number of milliseconds spent in this
    ms/call    function per call, if this function is profiled,
    	   else blank.
    
     total     the average number of milliseconds spent in this
    ms/call    function and its descendents per call, if this
    	   function is profiled, else blank.
    
    name       the name of the function.  This is the minor sort
               for this listing. The index shows the location of
    	   the function in the gprof listing. If the index is
    	   in parenthesis it shows where it would appear in
    	   the gprof listing if it were to be printed.
    
    Copyright (C) 2012-2020 Free Software Foundation, Inc.
    
    Copying and distribution of this file, with or without modification,
    are permitted in any medium without royalty provided the copyright
    notice and this notice are preserved.
    
    		     Call graph (explanation follows)
    
    
    granularity: each sample hit covers 4 byte(s) no time propagated
    
    index % time    self  children    called     name
                    0.00    0.00       1/3           std::enable_if<(!QtPrivate::FunctionPointer<main::{lambda()#1}>::IsPointerToMemberFunction)&&(!std::is_same<char const*, QtPrivate::FunctionPointer>::value), void>::type QTimer::singleShot<int, main::{lambda()#1}>(int, QtPrivate::FunctionPointer) [14]
                    0.00    0.00       1/3           std::enable_if<(!QtPrivate::FunctionPointer<main::{lambda()#1}>::IsPointerToMemberFunction)&&(!std::is_same<char const*, QtPrivate::FunctionPointer>::value), void>::type QTimer::singleShot<int, main::{lambda()#1}>(int, Qt::TimerType, QObject const*, QtPrivate::FunctionPointer) [13]
                    0.00    0.00       1/3           QtPrivate::QFunctorSlotObject<main::{lambda()#1}, 0, QtPrivate::List<>, void>::QFunctorSlotObject({lambda()#1}) [20]
    [9]      0.0    0.00    0.00       3         std::remove_reference<main::{lambda()#1}&>::type&& std::move<main::{lambda()#1}&>(std::remove_reference&&) [9]
    -----------------------------------------------
                    0.00    0.00       1/1           QtPrivate::QSlotObjectBase::QSlotObjectBase(void (*)(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*)) [17]
    [10]     0.0    0.00    0.00       1         QAtomicInt::QAtomicInt(int) [10]
                    0.00    0.00       1/1           QAtomicInteger<int>::QAtomicInteger(int) [11]
    -----------------------------------------------
                    0.00    0.00       1/1           QAtomicInt::QAtomicInt(int) [10]
    [11]     0.0    0.00    0.00       1         QAtomicInteger<int>::QAtomicInteger(int) [11]
                    0.00    0.00       1/1           QBasicAtomicInteger<int>::QBasicAtomicInteger(int) [12]
    -----------------------------------------------
                    0.00    0.00       1/1           QAtomicInteger<int>::QAtomicInteger(int) [11]
    [12]     0.0    0.00    0.00       1         QBasicAtomicInteger<int>::QBasicAtomicInteger(int) [12]
                    0.00    0.00       1/1           std::atomic<int>::atomic(int) [24]
    -----------------------------------------------
                    0.00    0.00       1/1           std::enable_if<(!QtPrivate::FunctionPointer<main::{lambda()#1}>::IsPointerToMemberFunction)&&(!std::is_same<char const*, QtPrivate::FunctionPointer>::value), void>::type QTimer::singleShot<int, main::{lambda()#1}>(int, QtPrivate::FunctionPointer) [14]
    [13]     0.0    0.00    0.00       1         std::enable_if<(!QtPrivate::FunctionPointer<main::{lambda()#1}>::IsPointerToMemberFunction)&&(!std::is_same<char const*, QtPrivate::FunctionPointer>::value), void>::type QTimer::singleShot<int, main::{lambda()#1}>(int, Qt::TimerType, QObject const*, QtPrivate::FunctionPointer) [13]
                    0.00    0.00       1/3           std::remove_reference<main::{lambda()#1}&>::type&& std::move<main::{lambda()#1}&>(std::remove_reference&&) [9]
                    0.00    0.00       1/1           QtPrivate::QFunctorSlotObject<main::{lambda()#1}, 0, QtPrivate::List<>, void>::QFunctorSlotObject({lambda()#1}) [20]
    -----------------------------------------------
                    0.00    0.00       1/1           main [7]
    [14]     0.0    0.00    0.00       1         std::enable_if<(!QtPrivate::FunctionPointer<main::{lambda()#1}>::IsPointerToMemberFunction)&&(!std::is_same<char const*, QtPrivate::FunctionPointer>::value), void>::type QTimer::singleShot<int, main::{lambda()#1}>(int, QtPrivate::FunctionPointer) [14]
                    0.00    0.00       1/1           QTimer::defaultTypeFor(int) [15]
                    0.00    0.00       1/3           std::remove_reference<main::{lambda()#1}&>::type&& std::move<main::{lambda()#1}&>(std::remove_reference&&) [9]
                    0.00    0.00       1/1           std::enable_if<(!QtPrivate::FunctionPointer<main::{lambda()#1}>::IsPointerToMemberFunction)&&(!std::is_same<char const*, QtPrivate::FunctionPointer>::value), void>::type QTimer::singleShot<int, main::{lambda()#1}>(int, Qt::TimerType, QObject const*, QtPrivate::FunctionPointer) [13]
    -----------------------------------------------
                    0.00    0.00       1/1           std::enable_if<(!QtPrivate::FunctionPointer<main::{lambda()#1}>::IsPointerToMemberFunction)&&(!std::is_same<char const*, QtPrivate::FunctionPointer>::value), void>::type QTimer::singleShot<int, main::{lambda()#1}>(int, QtPrivate::FunctionPointer) [14]
    [15]     0.0    0.00    0.00       1         QTimer::defaultTypeFor(int) [15]
    -----------------------------------------------
                    0.00    0.00       1/1           void QtPrivate::Functor<main::{lambda()#1}, 0>::call<QtPrivate::List<>, void>({lambda()#1}&, void*, {lambda()#1}&*) [22]
    [16]     0.0    0.00    0.00       1         QtPrivate::FunctorCall<QtPrivate::IndexesList<>, QtPrivate::List<>, void, main::{lambda()#1}>::call({lambda()#1}&, void**) [16]
                    0.00    0.00       1/1           main::{lambda()#1}::operator()() const [25]
                    0.00    0.00       1/1           QtPrivate::ApplyReturnValue<void>::ApplyReturnValue(void*) [19]
    -----------------------------------------------
                    0.00    0.00       1/1           QtPrivate::QFunctorSlotObject<main::{lambda()#1}, 0, QtPrivate::List<>, void>::QFunctorSlotObject({lambda()#1}) [20]
    [17]     0.0    0.00    0.00       1         QtPrivate::QSlotObjectBase::QSlotObjectBase(void (*)(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*)) [17]
                    0.00    0.00       1/1           QAtomicInt::QAtomicInt(int) [10]
    -----------------------------------------------
                    0.00    0.00       1/1           QtPrivate::QFunctorSlotObject<main::{lambda()#1}, 0, QtPrivate::List<>, void>::~QFunctorSlotObject() [21]
    [18]     0.0    0.00    0.00       1         QtPrivate::QSlotObjectBase::~QSlotObjectBase() [18]
    -----------------------------------------------
                    0.00    0.00       1/1           QtPrivate::FunctorCall<QtPrivate::IndexesList<>, QtPrivate::List<>, void, main::{lambda()#1}>::call({lambda()#1}&, void**) [16]
    [19]     0.0    0.00    0.00       1         QtPrivate::ApplyReturnValue<void>::ApplyReturnValue(void*) [19]
    -----------------------------------------------
                    0.00    0.00       1/1           std::enable_if<(!QtPrivate::FunctionPointer<main::{lambda()#1}>::IsPointerToMemberFunction)&&(!std::is_same<char const*, QtPrivate::FunctionPointer>::value), void>::type QTimer::singleShot<int, main::{lambda()#1}>(int, Qt::TimerType, QObject const*, QtPrivate::FunctionPointer) [13]
    [20]     0.0    0.00    0.00       1         QtPrivate::QFunctorSlotObject<main::{lambda()#1}, 0, QtPrivate::List<>, void>::QFunctorSlotObject({lambda()#1}) [20]
                    0.00    0.00       1/1           QtPrivate::QSlotObjectBase::QSlotObjectBase(void (*)(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*)) [17]
                    0.00    0.00       1/3           std::remove_reference<main::{lambda()#1}&>::type&& std::move<main::{lambda()#1}&>(std::remove_reference&&) [9]
    -----------------------------------------------
                    0.00    0.00       1/1           QtPrivate::QFunctorSlotObject<main::{lambda()#1}, 0, QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*) [26]
    [21]     0.0    0.00    0.00       1         QtPrivate::QFunctorSlotObject<main::{lambda()#1}, 0, QtPrivate::List<>, void>::~QFunctorSlotObject() [21]
                    0.00    0.00       1/1           QtPrivate::QSlotObjectBase::~QSlotObjectBase() [18]
    -----------------------------------------------
                    0.00    0.00       1/1           QtPrivate::QFunctorSlotObject<main::{lambda()#1}, 0, QtPrivate::List<>, void>::impl(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*) [26]
    [22]     0.0    0.00    0.00       1         void QtPrivate::Functor<main::{lambda()#1}, 0>::call<QtPrivate::List<>, void>({lambda()#1}&, void*, {lambda()#1}&*) [22]
                    0.00    0.00       1/1           QtPrivate::FunctorCall<QtPrivate::IndexesList<>, QtPrivate::List<>, void, main::{lambda()#1}>::call({lambda()#1}&, void**) [16]
    -----------------------------------------------
                    0.00    0.00       1/1           std::atomic<int>::atomic(int) [24]
    [23]     0.0    0.00    0.00       1         std::__atomic_base<int>::__atomic_base(int) [23]
    -----------------------------------------------
                    0.00    0.00       1/1           QBasicAtomicInteger<int>::QBasicAtomicInteger(int) [12]
    [24]     0.0    0.00    0.00       1         std::atomic<int>::atomic(int) [24]
                    0.00    0.00       1/1           std::__atomic_base<int>::__atomic_base(int) [23]
    -----------------------------------------------
                    0.00    0.00       1/1           QtPrivate::FunctorCall<QtPrivate::IndexesList<>, QtPrivate::List<>, void, main::{lambda()#1}>::call({lambda()#1}&, void**) [16]
    [25]     0.0    0.00    0.00       1         main::{lambda()#1}::operator()() const [25]
    -----------------------------------------------
    
     This table describes the call tree of the program, and was sorted by
     the total amount of time spent in each function and its children.
    
     Each entry in this table consists of several lines.  The line with the
     index number at the left hand margin lists the current function.
     The lines above it list the functions that called this function,
     and the lines below it list the functions this one called.
     This line lists:
         index	A unique number given to each element of the table.
    		Index numbers are sorted numerically.
    		The index number is printed next to every function name so
    		it is easier to look up where the function is in the table.
    
         % time	This is the percentage of the `total' time that was spent
    		in this function and its children.  Note that due to
    		different viewpoints, functions excluded by options, etc,
    		these numbers will NOT add up to 100%.
    
         self	This is the total amount of time spent in this function.
    
         children	This is the total amount of time propagated into this
    		function by its children.
    
         called	This is the number of times the function was called.
    		If the function called itself recursively, the number
    		only includes non-recursive calls, and is followed by
    		a `+' and the number of recursive calls.
    
         name	The name of the current function.  The index number is
    		printed after it.  If the function is a member of a
    		cycle, the cycle number is printed between the
    		function's name and the index number.
    
    
     For the function's parents, the fields have the following meanings:
    
         self	This is the amount of time that was propagated directly
    		from the function into this parent.
    
         children	This is the amount of time that was propagated from
    		the function's children into this parent.
    
         called	This is the number of times this parent called the
    		function `/' the total number of times the function
    		was called.  Recursive calls to the function are not
    		included in the number after the `/'.
    
         name	This is the name of the parent.  The parent's index
    		number is printed after it.  If the parent is a
    		member of a cycle, the cycle number is printed between
    		the name and the index number.
    
     If the parents of the function cannot be determined, the word
     `<spontaneous>' is printed in the `name' field, and all the other
     fields are blank.
    
     For the function's children, the fields have the following meanings:
    
         self	This is the amount of time that was propagated directly
    		from the child into the function.
    
         children	This is the amount of time that was propagated from the
    		child's children to the function.
    
         called	This is the number of times the function called
    		this child `/' the total number of times the child
    		was called.  Recursive calls by the child are not
    		listed in the number after the `/'.
    
         name	This is the name of the child.  The child's index
    		number is printed after it.  If the child is a
    		member of a cycle, the cycle number is printed
    		between the name and the index number.
    
     If there are any cycles (circles) in the call graph, there is an
     entry for the cycle-as-a-whole.  This entry shows who called the
     cycle (as parents) and the members of the cycle (as children.)
     The `+' recursive calls entry shows the number of function calls that
     were internal to the cycle, and the calls entry for each member shows,
     for that member, how many times it was called from other members of
     the cycle.
    
    Copyright (C) 2012-2020 Free Software Foundation, Inc.
    
    Copying and distribution of this file, with or without modification,
    are permitted in any medium without royalty provided the copyright
    notice and this notice are preserved.
    
    Index by function name
    
      [10] QAtomicInt::QAtomicInt(int) [16] QtPrivate::FunctorCall<QtPrivate::IndexesList<>, QtPrivate::List<>, void, main::{lambda()#1}>::call({lambda()#1}&, void**) (qobjectdefs_impl.h) [22] void QtPrivate::Functor<main::{lambda()#1}, 0>::call<QtPrivate::List<>, void>({lambda()#1}&, void*, {lambda()#1}&*) (qobjectdefs_impl.h)
      [11] QAtomicInteger<int>::QAtomicInteger(int) [17] QtPrivate::QSlotObjectBase::QSlotObjectBase(void (*)(int, QtPrivate::QSlotObjectBase*, QObject*, void**, bool*)) [23] std::__atomic_base<int>::__atomic_base(int)
      [12] QBasicAtomicInteger<int>::QBasicAtomicInteger(int) [18] QtPrivate::QSlotObjectBase::~QSlotObjectBase() [24] std::atomic<int>::atomic(int)
      [13] std::enable_if<(!QtPrivate::FunctionPointer<main::{lambda()#1}>::IsPointerToMemberFunction)&&(!std::is_same<char const*, QtPrivate::FunctionPointer>::value), void>::type QTimer::singleShot<int, main::{lambda()#1}>(int, Qt::TimerType, QObject const*, QtPrivate::FunctionPointer) (qtimer.h) [19] QtPrivate::ApplyReturnValue<void>::ApplyReturnValue(void*) [9] std::remove_reference<main::{lambda()#1}&>::type&& std::move<main::{lambda()#1}&>(std::remove_reference&&) (move.h)
      [14] std::enable_if<(!QtPrivate::FunctionPointer<main::{lambda()#1}>::IsPointerToMemberFunction)&&(!std::is_same<char const*, QtPrivate::FunctionPointer>::value), void>::type QTimer::singleShot<int, main::{lambda()#1}>(int, QtPrivate::FunctionPointer) (qtimer.h) [20] QtPrivate::QFunctorSlotObject<main::{lambda()#1}, 0, QtPrivate::List<>, void>::QFunctorSlotObject({lambda()#1}) (qobjectdefs_impl.h) [25] main::{lambda()#1}::operator()() const (main.cpp)
      [15] QTimer::defaultTypeFor(int) [21] QtPrivate::QFunctorSlotObject<main::{lambda()#1}, 0, QtPrivate::List<>, void>::~QFunctorSlotObject() (qobjectdefs_impl.h)
    


  • I have test this code on a Colibri iMX6ULL
    No cpu usage (<0.3%)

    QT5.12.3 (build my self)

    top | grep test
    11433 root      20   0   67588   8564   7892 S  0.3  1.7   0:00.21 test      
    
    cat /rpoc/cpuinfo
    processor       : 0
    model name      : ARMv7 Processor rev 5 (v7l)
    BogoMIPS        : 12.00
    Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae 
    CPU implementer : 0x41
    CPU architecture: 7
    CPU variant     : 0x0
    CPU part        : 0xc07
    CPU revision    : 5
    
    Hardware        : Freescale i.MX6 UltraLite (Device Tree)
    Revision        : 0000
    Serial          : 06398965
    
    uname -a
    Linux colibri-imx6ull 4.9.166-2.8.6+gd899927728be #1 SMP Mon Apr 1 14:10:54 UTC 2019 armv7l GNU/Linux
    

    Sorry maybe try with old version of qt for check if is not a new bug



  • @sifourquier

    I switched to Yocto thud version which had Qt 15.11.3. I observed the same problem , the CPU usage is going high.

    Actually there should not be any Ethernet or WiFi connection to the Board when the application starts up , only then this is reproducible.
    And When it is running with 98% percent of CPU usage , if I connect my ethernet cable to the board ( no internet connection) , the CPU usage comes down. Again if I remove the cable , the CPU usage is normal.

    So it seems like , only at the application start up , QNetworkAccessManager is looking for some IP address to be assigned from the router either to eth0 or wlan0. It works properly else it keeps increasing the CPU and memory usage.


Log in to reply