Stopping a Kernel thread using a timer in linux -

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i trying stop kernel thread calling kthread_stop() inside function called timer.when load module kernel, kthread starting , stopping after specified time mentioned in timer giving error message in log.

can me solve problem new kernel thread programming.this code

#include <linux/kernel.h> #include <linux/module.h> #include <linux/timer.h> #include <linux/kthread.h> #include <linux/sched.h> module_license("gpl"); struct task_struct *task; static struct timer_list my_timer; int thread_function(void *data) {     printk(kern_alert"in thread function");     while(!kthread_should_stop()){     schedule();     } printk(kern_alert"after schedule\n"); return 1; }  void my_timer_callback( unsigned long data ){ printk( "my_timer_callback called (%ld).\n", jiffies ); printk(kern_alert"thread stopped\n"); kthread_stop(task); }  int init_module( void ){     int ret;     printk("timer module installing\n");      //my_timer.function, my_timer.data     setup_timer( &my_timer, my_timer_callback, 0 );      printk( "starting timer fire in 2000ms (%ld)\n", jiffies );     ret = mod_timer( &my_timer, jiffies + msecs_to_jiffies(2000) );     if (ret) printk("error in mod_timer\n");     printk(kern_info"-------------------- thread start------------------------");      task = kthread_run(thread_function,null,"kerneltthread");     printk(kern_alert"kernel thread name: %s\n",task->comm);      return 0; }  void cleanup_module( void ){     int ret;      ret = del_timer( &my_timer );     if (ret) printk("the timer still in use...\n");      printk("timer module uninstalling\n");      return; }   module_license("gpl");

this output message in log

aug  5 16:35:31 brao kernel: timer module installing aug  5 16:35:31 brao kernel: starting timer fire in 2000ms (4299209850) aug  5 16:35:31 brao kernel: -------------------- thread             start------------------------ aug  5 16:35:31 brao kernel: kernel thread name: kerneltthread aug  5 16:35:31 brao kernel: in thread function aug  5 16:35:33 brao kernel: my_timer_callback called (4299211856). aug  5 16:35:33 brao kernel: thread stopped aug  5 16:35:33 brao kernel: bug: scheduling while atomic: swapper/3/0/0x10000100 aug  5 16:35:33 brao kernel: after schedule

timer's function executed in softirq context, because of shouldn't sleep. my_timer_callback calls kthread_stop function, waits until kthread finished, sleep.

so, scheduling while atomic bug arised: function sleeps while shouldn't because of atomic context.


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