Create Workqueue
================

.. panels::
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        Topics in this section,

                * :ref:`Version Info <create_workqueue_0>`

                * :ref:`Learnings in this program <create_workqueue_1>`
                
                * :ref:`Explanation of Workqueue APIs <create_workqueue_2>`

                        * :ref:`create_workqueue <create_workqueue_3>`

                        * :ref:`INIT_WORK <create_workqueue_4>`

                        * :ref:`queue_work <create_workqueue_5>`
                        
                        * :ref:`destroy_workqueue <create_workqueue_6>`       

                        * :ref:`create_singlethread_workqueue <create_workqueue_46>`

                        * :ref:`create_freezable_workqueue <create_workqueue_47>`

                * :ref:`Example 1 : Creating a workqueue <create_workqueue_7>`

                        * :ref:`List of headers <create_workqueue_8>`
                
                        * :ref:`Module macros <create_workqueue_9>`

                        * :ref:`Initializing work <create_workqueue_10>`

                        * :ref:`Workqueue Handler Function <create_workqueue_11>`

                        * :ref:`Queue Start Function <create_workqueue_12>`

                        * :ref:`Queue Init Function <create_workqueue_13>`

                        * :ref:`Queue Stop Function <create_workqueue_14>`

                        * :ref:`Queue Exit Function <create_workqueue_15>`

                        * :ref:`Driver entry points <create_workqueue_16>`

                        * :ref:`See the full program below <create_workqueue_17>`

                        * :ref:`Makefile <create_workqueue_18>`

                        * :ref:`Compile and Load <create_workqueue_19>`

                * :ref:`Example 2 : Creating a single thread workqueue <create_workqueue_20>`

                        * :ref:`List of headers <create_workqueue_21>`
                
                        * :ref:`Module macros <create_workqueue_22>`

                        * :ref:`Initializing work <create_workqueue_23>`

                        * :ref:`Workqueue Handler Function <create_workqueue_24>`

                        * :ref:`Queue Start Function <create_workqueue_25>`

                        * :ref:`Queue Init Function <create_workqueue_26>`

                        * :ref:`Queue Stop Function <create_workqueue_27>`

                        * :ref:`Queue Exit Function <create_workqueue_28>`

                        * :ref:`Driver entry points <create_workqueue_29>`

                        * :ref:`See the full program below <create_workqueue_30>`

                        * :ref:`Makefile <create_workqueue_31>`

                        * :ref:`Compile and Load <create_workqueue_32>`

                * :ref:`Example 3 : Creating a freezable workqueue <create_workqueue_33>`

                        * :ref:`List of headers <create_workqueue_34>`
                
                        * :ref:`Module macros <create_workqueue_35>`

                        * :ref:`Initializing work <create_workqueue_36>`

                        * :ref:`Workqueue Handler Function <create_workqueue_37>`

                        * :ref:`Queue Start Function <create_workqueue_38>`

                        * :ref:`Queue Init Function <create_workqueue_39>`

                        * :ref:`Queue Stop Function <create_workqueue_40>`

                        * :ref:`Queue Exit Function <create_workqueue_41>`

                        * :ref:`Driver entry points <create_workqueue_42>`

                        * :ref:`See the full program below <create_workqueue_43>`

                        * :ref:`Makefile <create_workqueue_44>`

                        * :ref:`Compile and Load <create_workqueue_45>`

                        
.. _create_workqueue_0:
 
.. tab-set::
 
    .. tab-item:: Version Info

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

.. _create_workqueue_1:

.. tab-set::

    .. tab-item:: Learnings in this section

        * In this program, you are going to learn

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                :card: shadow

                * How to create workqueue ?

        .. panels::
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                :card: shadow

                * 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>`_

                        * `create_singlethread_workqueue <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L427>`_

                        * `create_freezable_workqueue <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L424>`_

        .. panels::
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                :card: shadow

                * 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>`_

.. _create_workqueue_2:

.. tab-set::

    .. tab-item:: Explanation of workqueue APIs

        .. _create_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);

        .. _create_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);     

        .. _create_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);

        .. _create_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);

        .. _create_workqueue_46:

        .. tab-set::

            .. tab-item:: create_singlethread_workqueue

                * Here is the function prototype of the API: `create_singlethread_workqueue <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L427>`_ 

                .. code-block:: c

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

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

                .. code-block:: c
        
                        my_workqueue = create_singlethread_workqueue(WQ_NAME);

        .. _create_workqueue_47:

        .. tab-set::

            .. tab-item:: create_freezable_workqueue

                * Here is the function prototype of the API: `create_freezable_workqueue <https://elixir.bootlin.com/linux/v6.2/source/include/linux/workqueue.h#L424>`_

                .. code-block:: c

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

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

                .. code-block:: c
                        
                        my_workqueue = create_freezable_workqueue(WQ_NAME);

.. _create_workqueue_7:

.. tab-set::

    .. tab-item:: Example 1 : Creating a workqueue

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

        .. _create_workqueue_8:

        .. 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>

        .. _create_workqueue_9:

        .. 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 create_workqueue");

        .. _create_workqueue_10:

        .. 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);

        .. _create_workqueue_11:

        .. tab-set::

            .. tab-item:: Workqueue Handler Function

                * This 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(500);
                                }
                        }

        .. _create_workqueue_12:

        .. 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);
                                queue_work(my_workqueue,&my_work_1);
                        }
 
        .. _create_workqueue_13:

        .. 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;
                        }

        .. _create_workqueue_14:

        .. 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");
                                destroy_workqueue(my_workqueue);
                        }

        .. _create_workqueue_15:

        .. 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;
                        }

        .. _create_workqueue_16:

        .. 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);

.. _create_workqueue_17:

.. tab-set::

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

        .. tab-set::

            .. tab-item:: tc1.c
                
                .. literalinclude:: create_workqueue/create_workqueue/tc1.c
	            :language: c
        	    :linenos:

.. _create_workqueue_18:

.. tab-set::

    .. tab-item:: Makefile

	.. literalinclude:: create_workqueue/create_workqueue/Makefile
		:language: c
		:linenos:

.. _create_workqueue_19:

.. 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 11:42 Makefile
		-rw-rw-r-- 1 test test     80 Aug  2 12:21 modules.order
		-rw-rw-r-- 1 test test      0 Aug  2 12:21 Module.symvers
		-rw-rw-r-- 1 test test   1736 Aug  2 11:42 tc1.c
		-rw-rw-r-- 1 test test 180760 Aug  2 12:21 tc1.ko
		-rw-rw-r-- 1 test test     80 Aug  2 12:21 tc1.mod
		-rw-rw-r-- 1 test test   1103 Aug  2 12:21 tc1.mod.c
		-rw-rw-r-- 1 test test 149288 Aug  2 12:21 tc1.mod.o
		-rw-rw-r-- 1 test test  32936 Aug  2 12:21 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
                [  237.521464] Inside queue_init function
		[  237.522188] Inside workqueue_func_1
		[  238.042620] Inside workqueue_func_1
		[  238.554641] Inside workqueue_func_1
		[  239.066622] Inside workqueue_func_1
		[  239.578636] Inside workqueue_func_1
		[  240.090615] Inside workqueue_func_1
		[  240.602564] Inside workqueue_func_1
		[  241.114599] Inside workqueue_func_1
		[  241.626673] Inside workqueue_func_1
		[  242.138618] 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
                [  251.832722] Inside queue_exit function
                [  251.832729] Destroying workqueue

.. _create_workqueue_20:

.. tab-set::

    .. tab-item:: Example 2 : Creating a single thread workqueue

        * In this example let's see how to create single thread workqueue and execute it.

        .. _create_workqueue_21:

        .. 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>

        .. _create_workqueue_22:

        .. 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 create_singlethread_workqueue");

        .. _create_workqueue_23:

        .. 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);

        .. _create_workqueue_24:

        .. tab-set::

            .. tab-item:: Workqueue Handler Function

                * This 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(500);
                                }
                        }

        .. _create_workqueue_25:

        .. 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_singlethread_workqueue(WQ_NAME);
                                INIT_WORK(&my_work_1,workqueue_func_1);
                                queue_work(my_workqueue,&my_work_1);
                        }
 
        .. _create_workqueue_26:

        .. 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;
                        }

        .. _create_workqueue_27:

        .. 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");
                                destroy_workqueue(my_workqueue);
                        }

        .. _create_workqueue_28:

        .. 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;
                        }

        .. _create_workqueue_29:

        .. 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);

.. _create_workqueue_30:

.. tab-set::

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

        .. tab-set::

            .. tab-item:: tc2.c
                
                .. literalinclude:: create_workqueue/create_singlethread_workqueue/tc2.c
	            :language: c
        	    :linenos:

.. _create_workqueue_31:

.. tab-set::

    .. tab-item:: Makefile

	.. literalinclude:: create_workqueue/create_singlethread_workqueue/Makefile
		:language: c
		:linenos:

.. _create_workqueue_32:

.. 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 12:28 Makefile
		-rw-rw-r-- 1 test test     93 Aug  2 12:28 modules.order
		-rw-rw-r-- 1 test test      0 Aug  2 12:28 Module.symvers
		-rw-rw-r-- 1 test test   1762 Aug  2 11:42 tc2.c
		-rw-rw-r-- 1 test test 180816 Aug  2 12:28 tc2.ko
		-rw-rw-r-- 1 test test     93 Aug  2 12:28 tc2.mod
		-rw-rw-r-- 1 test test   1103 Aug  2 12:28 tc2.mod.c
		-rw-rw-r-- 1 test test 149312 Aug  2 12:28 tc2.mod.o
		-rw-rw-r-- 1 test test  32968 Aug  2 12:28 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
                [  636.552146] Inside queue_init function
		[  636.552516] Inside workqueue_func_1
		[  637.082615] Inside workqueue_func_1
		[  637.594573] Inside workqueue_func_1
		[  638.106515] Inside workqueue_func_1
		[  638.618599] Inside workqueue_func_1
		[  639.134537] Inside workqueue_func_1
		[  639.642665] Inside workqueue_func_1
		[  640.154697] Inside workqueue_func_1
		[  640.666640] Inside workqueue_func_1
		[  641.178613] 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
                [  653.077727] Inside queue_exit function
                [  653.077730] Destroying workqueue

.. _create_workqueue_33:

.. tab-set::

    .. tab-item:: Example 3 : Creating a freezable workqueue

        * In this example let's see how to create freezable workqueue and execute it.

        .. _create_workqueue_34:

        .. 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>

        .. _create_workqueue_35:

        .. 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 create_freezable_workqueue");

        .. _create_workqueue_36:

        .. 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);

        .. _create_workqueue_37:

        .. tab-set::

            .. tab-item:: Workqueue Handler Function

                * This 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(500);
                                }
                        }

        .. _create_workqueue_38:

        .. 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_freezable_workqueue(WQ_NAME);
                                INIT_WORK(&my_work_1,workqueue_func_1);
                                queue_work(my_workqueue,&my_work_1);
                        }
 
        .. _create_workqueue_39:

        .. 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;
                        }

        .. _create_workqueue_40:

        .. 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");
                                destroy_workqueue(my_workqueue);
                        }

        .. _create_workqueue_41:

        .. 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;
                        }

        .. _create_workqueue_42:

        .. 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);

.. _create_workqueue_43:

.. tab-set::

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

        .. tab-set::

            .. tab-item:: tc3.c
                
                .. literalinclude:: create_workqueue/create_freezable_workqueue/tc3.c
	            :language: c
        	    :linenos:

.. _create_workqueue_44:

.. tab-set::

    .. tab-item:: Makefile

	.. literalinclude:: create_workqueue/create_freezable_workqueue/Makefile
		:language: c
		:linenos:

.. _create_workqueue_45:

.. 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 11:42 Makefile
		-rw-rw-r-- 1 test test     90 Aug  2 12:32 modules.order
		-rw-rw-r-- 1 test test      0 Aug  2 12:32 Module.symvers
		-rw-rw-r-- 1 test test   1756 Aug  2 11:42 tc3.c
		-rw-rw-r-- 1 test test 180800 Aug  2 12:32 tc3.ko
		-rw-rw-r-- 1 test test     90 Aug  2 12:32 tc3.mod
		-rw-rw-r-- 1 test test   1103 Aug  2 12:32 tc3.mod.c
		-rw-rw-r-- 1 test test 149304 Aug  2 12:32 tc3.mod.o
		-rw-rw-r-- 1 test test  32960 Aug  2 12:32 tc3.o

        * Load the module to kernel using insmod command.

        .. code-block:: shell

                $ sudo insmod ./tc3.ko
           
        * Check kernel messages to verify if the module is loaded or not.

        .. code-block:: shell
                
                $ dmesg
                [  866.843964] Inside queue_init function
		[  866.844248] Inside workqueue_func_1
		[  867.354660] Inside workqueue_func_1
		[  867.866729] Inside workqueue_func_1
		[  868.378724] Inside workqueue_func_1
		[  868.890716] Inside workqueue_func_1
		[  869.402722] Inside workqueue_func_1
		[  869.914731] Inside workqueue_func_1
		[  870.426712] Inside workqueue_func_1
		[  870.938724] Inside workqueue_func_1
		[  871.450719] Inside workqueue_func_1
           
        * Unload the module using rmmod command.

        .. code-block:: shell
                
                $ sudo rmmod tc3

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

        .. code-block:: shell

                $ dmesg
                [  885.279641] Inside queue_exit function
                [  885.279650] Destroying workqueue