Check Workqueue
===============

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        Topics in this section,

                * :ref:`Version Info <check_workqueue_0>`

                * :ref:`Learnings in this program <check_workqueue_1>`

                * :ref:`Explanation of Workqueue APIs <check_workqueue_2>`

                        * :ref:`create_workqueue <check_workqueue_3>`

                        * :ref:`INIT_WORK <check_workqueue_4>`

                        * :ref:`queue_work <check_workqueue_5>`

                        * :ref:`destroy_workqueue <check_workqueue_6>`

                        * :ref:`INIT_DELAYED_WORK <check_workqueue_8>`

                        * :ref:`queue_delayed_work <check_workqueue_9>`

                        * :ref:`cancel_delayed_work_sync <check_workqueue_10>`

                        * :ref:`schedule_delayed_work <check_workqueue_13>`

                        * :ref:`cancel_delayed_work <check_workqueue_14>`

                        * :ref:`work_pending <check_workqueue_7>`

                        * :ref:`schedule_work <check_workqueue_11>`

                        * :ref:`cancel_workqueue <check_workqueue_12>`

                * :ref:`Example 1 : Checking the workqueue <check_workqueue_18>`

                        * :ref:`List of headers <check_workqueue_19>`

                        * :ref:`Module macros <check_workqueue_20>`

                        * :ref:`Initializing work <check_workqueue_21>`

                        * :ref:`Workqueue Handler Function <check_workqueue_22>`

                        * :ref:`Queue Start Function <check_workqueue_23>`

                        * :ref:`Queue Init Function <check_workqueue_24>`

                        * :ref:`Queue Stop Function <check_workqueue_25>`

                        * :ref:`Queue Exit Function <check_workqueue_26>`

                        * :ref:`Driver entry points <check_workqueue_27>`

                        * :ref:`See the full program below <check_workqueue_28>`

                        * :ref:`Makefile <check_workqueue_29>`

                        * :ref:`Compile and Load <check_workqueue_30>`

                * :ref:`Example 2 : Checking the workqueue <check_workqueue_18>`

                        * :ref:`List of headers <check_workqueue_19>`

                        * :ref:`Module macros <check_workqueue_20>`

                        * :ref:`Initializing work <check_workqueue_21>`

                        * :ref:`Workqueue Handler Function <check_workqueue_22>`

                        * :ref:`Queue Start Function <check_workqueue_23>`

                        * :ref:`Queue Init Function <check_workqueue_24>`

                        * :ref:`Queue Stop Function <check_workqueue_25>`

                        * :ref:`Queue Exit Function <check_workqueue_26>`

                        * :ref:`Driver entry points <check_workqueue_27>`

                        * :ref:`See the full program below <check_workqueue_28>`

                        * :ref:`Makefile <check_workqueue_29>`

                        * :ref:`Compile and Load <check_workqueue_30>`

.. _check_workqueue_0:
 
.. tab-set::
 
    .. tab-item:: Version Info

        =============================== =======================================
        #                               Version
        =============================== =======================================
        Ubuntu                          Ubuntu 22.10
        Kernel                          6.8.0
        =============================== =======================================

.. _check_workqueue_1:

.. tab-set::

    .. tab-item:: Learnings in this section

        * In this program, you are going to learn

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                * How to create workqueue ?

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                * How to allocate the work to the queue ?

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                * How to use Workqueue APIs ?

                        * `create_workqueue <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L422>`_

                        * `INIT_WORK <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L244>`_

                        * `queue_work <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L500>`_

                        * `destroy_workqueue <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L430>`_

                        * `INIT_DELAYED_WORK <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L266>`_ 
                       
                        * `delayed_work_pending <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L296>`_

                        * `schedule_delayed_work <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L667>`_
                        
                        * `cancel_delayed_work_sync <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L461>`_
                        
                        * `cancel_delayed_work <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L460>`_
                          
                        * `work_pending <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L288>`_
                        
                        * `schedule_work <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L562>`_

                        * `cancel_work <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L456>`_

                        

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                * How to use below APIs ?

                        * `MODULE_LICENSE <https://elixir.bootlin.com/linux/v6.7.9/source/include/linux/module.h#L230>`_

                        * `MODULE_DESCRIPTION <https://elixir.bootlin.com/linux/v6.7.9/source/include/linux/module.h#L239>`_

                        * `MODULE_AUTHOR <https://elixir.bootlin.com/linux/v6.7.9/source/include/linux/module.h#L236>`_

                        * `module_init <https://elixir.bootlin.com/linux/v6.7.9/source/include/linux/module.h#L88>`_

                        * `module_exit <https://elixir.bootlin.com/linux/v6.7.9/source/include/linux/module.h#L100>`_

.. _check_workqueue_2:

.. tab-set::

    .. tab-item:: Explanation of workqueue APIs

        .. _check_workqueue_3:

        .. tab-set::

            .. tab-item:: create_workqueue

                * Here is the function prototype of the API: `create_workqueue <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L422>`_

                .. code-block:: c

                        #include <linux/workqueue.h>
                        
                        #define create_workqueue(name)

                * Here is an example of how to use the API,

                .. code-block:: c

                        my_workqueue = create_workqueue(WQ_NAME);

        .. _check_workqueue_4:

        .. tab-set::

            .. tab-item:: INIT_WORK

                * Here is the function prototype of the API: `INIT_WORK <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L244>`_

                .. code-block:: c

                        #include <linux/workqueue.h>
                        
                        #define INIT_WORK(_work, _func)

                * Here is an example of how to use the API,

                .. code-block:: c
        
                        INIT_WORK(&my_work_1,workqueue_func_1);     

        .. _check_workqueue_5:

        .. tab-set::

            .. tab-item:: queue_work

                * Here is the function prototype of the API: `queue_work <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L500>`_ 

                .. code-block:: c

                        #include <linux/workqueue.h>
                        
                        static inline bool queue_work(struct workqueue_struct *wq, struct work_struct *work);

                * Here is an example of how to use the API,

                .. code-block:: c

                        queue_work(my_workqueue,&my_work_1);

        .. _check_workqueue_6:

        .. tab-set::

            .. tab-item:: destroy_workqueue

                * Here is the function prototype of the API: `queue_work <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L500>`_ 

                .. code-block:: c

                        #include <linux/workqueue.h>
                        
                        extern void destroy_workqueue(struct workqueue_struct *wq);

                * Here is an example of how to use the API,

                .. code-block:: c
        
                        destroy_workqueue(my_workqueue);

        .. _check_workqueue_7:

        .. tab-set::

            .. tab-item:: work_pending

                * Here is the function prototype of the API: `work_pending <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L288>`_

                .. code-block:: c

                        #include <linux/workqueue.h>

                        #define work_pending(work)

                * Here is an example of how to use the API,

                .. code-block:: c
        
                        work_pending(&my_work_1);

        .. _check_workqueue_8:

        .. tab-set::

            .. tab-item:: INIT_DELAYED_WORK

                * Here is the function prototype of the API: `INIT_DELAYED_WORK <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L266>`_

                .. code-block:: c

                        #include <linux/workqueue.h>
        
                        #define INIT_DELAYED_WORK(_work, _func)

                * Here is an example of how to use the API,

                .. code-block:: c

                        INIT_DELAYED_WORK(&my_work_1,workqueue_func_1);
                        INIT_DELAYED_WORK(&my_work_2,workqueue_func_2);
        
        .. _check_workqueue_9:

        .. tab-set::

            .. tab-item:: delayed_work_pending

                * Here is the function prototype of the API: `delayed_work_pending <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L296>`_ 

                .. code-block:: c

                        #include <linux/workqueue.h>

                        #define delayed_work_pending(w)

                * Here is an example of how to use the API,

                .. code-block:: c
        
                        delayed_work_pending(&my_work_1);

        .. _check_workqueue_10:

        .. tab-set::

            .. tab-item:: cancel_delayed_work_sync

                * Here is the function prototype of the API: `cancel_delayed_work_sync <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L461>`_

                .. code-block:: c

                        #include <linux/workqueue.h>

                        extern bool cancel_delayed_work_sync(struct delayed_work *dwork);

                * Here is an example of how to use the API,

                .. code-block:: c

                        cancel_delayed_work_sync(&my_work_1);
                        cancel_delayed_work_sync(&my_work_2);
        
        .. _check_workqueue_11:

        .. tab-set::

            .. tab-item:: schedule_work

                * Here is the function prototype of the API: `schedule_work <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L562>`_

                .. code-block:: c

                        #include <linux/workqueue.h>
                        
                        static inline bool schedule_work(struct work_struct *work);

                * Here is an example of how to use the API,

                .. code-block:: c
        
                        schedule_work(&my_work_1);
                        schedule_work(&my_work_2);

        .. _check_workqueue_12:

        .. tab-set::

            .. tab-item:: cancel_work 

                * Here is the function prototype of the API: `cancel_work <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L456>`_                
                
                .. code-block:: c

                        #include <linux/workqueue.h>

                        extern bool cancel_work(struct work_struct *work);

                * Here is an example of how to use the API,

                .. code-block:: c

                        cancel_work(&my_work_1);
                        cancel_work(&my_work_2); 

        .. _check_workqueue_13:

        .. tab-set::

            .. tab-item:: schedule_delayed_work

                * Here is the function prototype of the API: `schedule_delayed_work <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L667>`_

                .. code-block:: c

                        #include <linux/workqueue.h>

                        static inline bool schedule_delayed_work(struct delayed_work *dwork, unsigned long delay);

                * Here is an example of how to use the API,

                .. code-block:: c
                        
                        schedule_delayed_work(&my_work,msecs_to_jiffies(100));

        .. _check_workqueue_14:

        .. tab-set::

            .. tab-item:: cancel_delayed_work

                * Here is the function prototype of the API: `cancel_delayed_work <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L460>`_

                .. code-block:: c

                        #include <linux/workqueue.h>

                        extern bool cancel_delayed_work(struct delayed_work *dwork);

                * Here is an example of how to use the API,

                .. code-block:: c
                        
                        cancel_delayed_work(&my_work);

.. _check_workqueue_18:

.. tab-set::

    .. tab-item:: Example 1 : Checking the workqueue

        * In this example let's see how to check the workqueue and execute it.

        .. _check_workqueue_19:

        .. tab-set::

            .. tab-item:: List of headers

                * Include the follow header files(.h) to refer the API being used for the execution.

                .. code-block:: c

                        #include <linux/init.h>
                        #include <linux/kernel.h>
                        #include <linux/module.h>
                        #include <linux/workqueue.h>
                        #include <linux/delay.h>
                        #include <linux/jiffies.h>

        .. _check_workqueue_20:

        .. tab-set::

            .. tab-item:: Module macros

                * Add the following module macros to display information about the license, author and description about the module.

                .. code-block:: c

                        MODULE_LICENSE("GPL");
                        MODULE_AUTHOR("Linux_usr");
                        MODULE_DESCRIPTION("Example of work_pending");

        .. _check_workqueue_21:

        .. tab-set::

            .. tab-item:: Initializing work

                * Initialize the work which we are going to use in this example

                .. code-block:: c

                        INIT_WORK(&my_work_1,workqueue_func_1);
                        INIT_WORK(&my_work_2,workqueue_func_2);

        .. _check_workqueue_22:

        .. tab-set::

            .. tab-item:: Workqueue Handler Function

                * This workqueue_func_1 function executes when work is queued to workqueue.

                .. code-block:: c

                        void workqueue_func_1(struct work_struct *work)
                        {
                                int i = 0;
                                while (i < 10) {
                                        pr_info("Inside workqueue_func_1\n");
                                        i++;
                                        msleep(1000);
                                }
                        }

                * This workqueue_func_2 function executes when work is queued to workqueue.

                .. code-block:: c

                        void workqueue_func_2(struct work_struct *work)
                        {
                                int i = 0;
                                while (i < 10) {
                                        pr_info("Inside workqueue_func_1\n");
                                        i++;
                                        msleep(1000);
                                }
                        }
             
        .. _check_workqueue_23:

        .. tab-set::

            .. tab-item:: Queue Start Function

                * This function creates workqueue, intiializes work and queues to the workqueue.

                .. code-block:: c

                        void queue_start(void)
			{
			    my_workqueue = create_workqueue(WQ_NAME);
			    INIT_WORK(&my_work_1,workqueue_func_1);
			    INIT_WORK(&my_work_2,workqueue_func_2);
			    if (!work_pending(&my_work_1)) {
				schedule_work(&my_work_1);
				queue_work(my_workqueue,&my_work_1);
			    }
			    if (!work_pending(&my_work_2)) {
				schedule_work(&my_work_2);
				queue_work(my_workqueue,&my_work_2);
			    }
			}
 
        .. _check_workqueue_24:

        .. tab-set::

            .. tab-item:: Queue Init Function

                * This function executes when module is loaded.

                .. code-block:: c

                        static int __init queue_init(void)
                        {
                                pr_info("Inside queue_init function\n");
                                queue_start();
                                return 0;
                        }

        .. _check_workqueue_25:

        .. tab-set::

            .. tab-item:: Queue Stop Function

                * This function executes during execution of queue_exit, waits until the completion and destroys workqueue.

                .. code-block:: c

                        void queue_stop(void)
                        {
                                pr_info("Destroying workqueue\n");
                                cancel_work(&my_work_1);
                                cancel_work(&my_work_2);
                        }

        .. _check_workqueue_26:

        .. tab-set::

            .. tab-item:: Queue Exit Function

                * This function executes when module is unloaded.

                .. code-block:: c

                        static void __exit queue_exit(void)
                        {
                                pr_info("Inside queue_exit function\n");
                                queue_stop();
                                return;
                        }

        .. _check_workqueue_27:

        .. tab-set::

            .. tab-item:: Driver entry points

                * Add the driver entry points which will be executed once the module is inserted or removed from the kernel.

                .. code-block:: c

                        module_init(queue_init);
                        module_exit(queue_exit);

.. _check_workqueue_28:

.. tab-set::

    .. tab-item:: See the full program below

        .. tab-set::

            .. tab-item:: tc1.c
                
                .. literalinclude:: check_workqueue/work_pending/tc1.c
	            :language: c
        	    :linenos:

.. _check_workqueue_29:

.. tab-set::

    .. tab-item:: Makefile

	.. literalinclude:: check_workqueue/work_pending/Makefile
		:language: c
		:linenos:

.. _check_workqueue_30:

.. tab-set::

    .. tab-item:: Compile and Load
        
        * Run make to load the kernel module.

        .. code-block:: shell

                $ make

        * Check if work_queue.ko is generated or not using ls command.

        .. code-block:: shell

                $ ls -l
                total 384
		-rw-rw-r-- 1 test test    151 Aug  2 11:47 Makefile
		-rw-rw-r-- 1 test test     76 Aug  2 12:48 modules.order
		-rw-rw-r-- 1 test test      0 Aug  2 12:48 Module.symvers
		-rw-rw-r-- 1 test test   2040 Aug  2 11:47 tc1.c
		-rw-rw-r-- 1 test test 180944 Aug  2 12:48 tc1.ko
		-rw-rw-r-- 1 test test     76 Aug  2 12:48 tc1.mod
		-rw-rw-r-- 1 test test   1103 Aug  2 12:48 tc1.mod.c
		-rw-rw-r-- 1 test test 149280 Aug  2 12:48 tc1.mod.o
		-rw-rw-r-- 1 test test  33112 Aug  2 12:48 tc1.o

        * Load the module to kernel using insmod command.

        .. code-block:: shell

                $ sudo insmod ./tc1.ko
           
        * Check kernel messages to verify if the module is loaded or not.

        .. code-block:: shell
                
                $ dmesg
                [ 1812.726131] Inside queue_init function
                [ 1812.726612] Inside workqueue_func_2
                [ 1812.726979] Inside workqueue_func_1
                [ 1813.754717] Inside workqueue_func_1
                [ 1814.778711] Inside workqueue_func_1
                [ 1815.802723] Inside workqueue_func_1
                [ 1816.826704] Inside workqueue_func_1
                [ 1817.850705] Inside workqueue_func_1
                [ 1818.874707] Inside workqueue_func_1
                [ 1819.898722] Inside workqueue_func_1
                [ 1820.922729] Inside workqueue_func_1
                [ 1821.946714] Inside workqueue_func_1
           
        * Unload the module using rmmod command.

        .. code-block:: shell
                
                $ sudo rmmod tc1 

        * Check kernel messages to see if the module is unloaded or not.

        .. code-block:: shell

                $ dmesg
                [ 1835.094347] Inside queue_exit function

.. _check_workqueue_31:

.. tab-set::

    .. tab-item:: Example 2 : Checking the workqueue

        * In this example let's see how to check the workqueue and execute it.

        .. _check_workqueue_32:

        .. tab-set::

            .. tab-item:: List of headers

                * Include the follow header files(.h) to refer the API being used for the execution.

                .. code-block:: c

                        #include <linux/init.h>
                        #include <linux/kernel.h>
                        #include <linux/module.h>
                        #include <linux/workqueue.h>
                        #include <linux/delay.h>
                        #include <linux/jiffies.h>

        .. _check_workqueue_33:

        .. tab-set::

            .. tab-item:: Module macros

                * Add the following module macros to display information about the license, author and description about the module.

                .. code-block:: c

                        MODULE_LICENSE("GPL");
                        MODULE_AUTHOR("Linux_usr");
                        MODULE_DESCRIPTION("Example of delayed_work_pending");

        .. _check_workqueue_34:

        .. tab-set::

            .. tab-item:: Initializing work

                * Initialize the work which we are going to use in this example

                .. code-block:: c

                        INIT_WORK_ONSTACK(&my_work_1,workqueue_func_1);
                        INIT_WORK_ONSTACK(&my_work_2,workqueue_func_2);

        .. _check_workqueue_35:

        .. tab-set::

            .. tab-item:: Workqueue Handler Function

                * This workqueue_func_1 function executes when work is queued to workqueue.

                .. code-block:: c

                        void workqueue_func_1(struct work_struct *work)
                        {
                                int i = 0;
                                while (i < 10) {
                                        pr_info("Inside workqueue_func_1\n");
                                        i++;
                                        msleep(1000);
                                }
                        }

                * This workqueue_func_2 function executes when work is queued to workqueue.

                .. code-block:: c

                        void workqueue_func_2(struct work_struct *work)
                        {
                                int i = 0;
                                while (i < 10) {
                                        pr_info("Inside workqueue_func_2\n");
                                        i++;
                                        msleep(1000);
                                }           
                        }

        .. _check_workqueue_36:

        .. tab-set::

            .. tab-item:: Queue Start Function

                * This function creates workqueue, intiializes work and queues to the workqueue.

                .. code-block:: c

                        void queue_start(void)
			{
			    INIT_DELAYED_WORK(&my_work_1,workqueue_func_1);
			    INIT_DELAYED_WORK(&my_work_2,workqueue_func_2);
			    if (!delayed_work_pending(&my_work_1)) {
				pr_info("Delayed work is not scheduled yet\n");
				schedule_delayed_work(&my_work_1,msecs_to_jiffies(500));
			    }
			    schedule_delayed_work(&my_work_2,msecs_to_jiffies(500));
			}
 
        .. _check_workqueue_37:

        .. tab-set::

            .. tab-item:: Queue Init Function

                * This function executes when module is loaded.

                .. code-block:: c

                        static int __init queue_init(void)
                        {
                                pr_info("Inside queue_init function\n");
                                queue_start();
                                return 0;
                        }

        .. _check_workqueue_38:

        .. tab-set::

            .. tab-item:: Queue Stop Function

                * This function executes during execution of queue_exit, waits until the completion and destroys workqueue.

                .. code-block:: c

                        void queue_stop(void)
			{
			    pr_info("Destroying workqueue\n");
			    cancel_delayed_work_sync(&my_work_1);
			    cancel_delayed_work(&my_work_2);
			}

        .. _check_workqueue_39:

        .. tab-set::

            .. tab-item:: Queue Exit Function

                * This function executes when module is unloaded.

                .. code-block:: c

                        static void __exit queue_exit(void)
                        {
                                pr_info("Inside queue_exit function\n");
                                queue_stop();
                                return;
                        }

        .. _check_workqueue_40:

        .. tab-set::

            .. tab-item:: Driver entry points

                * Add the driver entry points which will be executed once the module is inserted or removed from the kernel.

                .. code-block:: c

                        module_init(queue_init);
                        module_exit(queue_exit);

.. _check_workqueue_41:

.. tab-set::

    .. tab-item:: See the full program below

        .. tab-set::

            .. tab-item:: tc2.c
                
                .. literalinclude:: check_workqueue/delayed_work_pending/tc2.c
	            :language: c
        	    :linenos:

.. _check_workqueue_42:

.. tab-set::

    .. tab-item:: Makefile

	.. literalinclude:: check_workqueue/delayed_work_pending/Makefile
		:language: c
		:linenos:

.. _check_workqueue_43:

.. tab-set::

    .. tab-item:: Compile and Load
        
        * Run make to load the kernel module.

        .. code-block:: shell

                $ make

        * Check if work_queue.ko is generated or not using ls command.

        .. code-block:: shell

                $ ls -l
                total 384
		-rw-rw-r-- 1 test test    151 Aug  2 11:47 Makefile
		-rw-rw-r-- 1 test test     84 Aug  2 12:51 modules.order
		-rw-rw-r-- 1 test test      0 Aug  2 12:51 Module.symvers
		-rw-rw-r-- 1 test test   2356 Aug  2 11:47 tc2.c
		-rw-rw-r-- 1 test test 181992 Aug  2 12:51 tc2.ko
		-rw-rw-r-- 1 test test     84 Aug  2 12:51 tc2.mod
		-rw-rw-r-- 1 test test   1103 Aug  2 12:51 tc2.mod.c
		-rw-rw-r-- 1 test test 149296 Aug  2 12:51 tc2.mod.o
		-rw-rw-r-- 1 test test  34160 Aug  2 12:51 tc2.o

        * Load the module to kernel using insmod command.

        .. code-block:: shell

                $ sudo insmod ./tc2.ko
           
        * Check kernel messages to verify if the module is loaded or not.

        .. code-block:: shell
                
                $ dmesg
                [ 1927.976881] Inside queue_init function
		[ 1927.977802] Inside workqueue_func_1
		[ 1927.977886] Inside workqueue_func_2
		[ 1928.986617] Inside workqueue_func_2
		[ 1928.986634] Inside workqueue_func_1
		[ 1930.010693] Inside workqueue_func_2
		[ 1930.010731] Inside workqueue_func_1
		[ 1931.034722] Inside workqueue_func_2
		[ 1931.034739] Inside workqueue_func_1
		[ 1932.058735] Inside workqueue_func_2
		[ 1932.058751] Inside workqueue_func_1
		[ 1933.082732] Inside workqueue_func_2
		[ 1933.082760] Inside workqueue_func_1
		[ 1934.106692] Inside workqueue_func_1
		[ 1934.106709] Inside workqueue_func_2
		[ 1935.130737] Inside workqueue_func_2
		[ 1935.130753] Inside workqueue_func_1
		[ 1936.154741] Inside workqueue_func_1
		[ 1936.154758] Inside workqueue_func_2
		[ 1937.178738] Inside workqueue_func_2
		[ 1937.178755] Inside workqueue_func_1
           
        * Unload the module using rmmod command.

        .. code-block:: shell
                
                $ sudo rmmod tc2

        * Check kernel messages to see if the module is unloaded or not.

        .. code-block:: shell

                $ dmesg
                [ 1955.215382] Inside queue_exit function