kernel tasklets, and work queues

Simple example of a tasklet in the context of a kernel module:

#include <linux/kernel.h>#include <linux/module.h>#include <linux/interrupt.h>MODULE_LICENSE("GPL");char my_tasklet_data[]="my_tasklet_function was called";/* Bottom Half Function */void my_tasklet_function( unsigned long data ){  printk( "%s\n", (char *)data );  return;}DECLARE_TASKLET( my_tasklet, my_tasklet_function,  (unsigned long) &my_tasklet_data );int init_module( void ){  /* Schedule the Bottom Half */  tasklet_schedule( &my_tasklet );  return 0;}void cleanup_module( void ){  /* Stop the tasklet before we exit */  tasklet_kill( &my_tasklet );  return;}

Simple work queue example

#include <linux/kernel.h>#include <linux/module.h>#include <linux/workqueue.h>MODULE_LICENSE("GPL");static struct workqueue_struct *my_wq;typedef struct {  struct work_struct my_work;  int    x;} my_work_t;my_work_t *work, *work2;static void my_wq_function( struct work_struct *work){  my_work_t *my_work = (my_work_t *)work;  printk( "my_work.x %d\n", my_work->x );  kfree( (void *)work );  return;}

int init_module( void ){  int ret;  my_wq = create_workqueue("my_queue");  if (my_wq) {    /* Queue some work (item 1) */    work = (my_work_t *)kmalloc(sizeof(my_work_t), GFP_KERNEL);    if (work) {      INIT_WORK( (struct work_struct *)work, my_wq_function );      work->x = 1;      ret = queue_work( my_wq, (struct work_struct *)work );    }    /* Queue some additional work (item 2) */    work2 = (my_work_t *)kmalloc(sizeof(my_work_t), GFP_KERNEL);    if (work2) {      INIT_WORK( (struct work_struct *)work2, my_wq_function );      work2->x = 2;      ret = queue_work( my_wq, (struct work_struct *)work2 );    }  }  return 0;}

void cleanup_module( void ){  flush_workqueue( my_wq );  destroy_workqueue( my_wq );  return;}