Hello Thomas,
Could you please send any example or link for the code you mentioned below.
Thanks & Regards
Jhoney
On Fri, 05 Aug 2005 Thomas Petazzoni wrote :
>Hi,
>
>jhoney jhoney a écrit :
>
> > My requirement is like this. I am calling some blocking calls. if I create one
> > thread for one blocking call, another blocking call comes with is not adding to
> > the task list when I used tasklet. So I am going to threads now.
> >
> > If I call threads from interrupt service routine, the arguments are not getting
> > passed correctly to the thread. How to make interrupt service routine small and
> > spaw new thread for each call.
>
>You don't want to spawn a thread for each call. You want to add stuff in
>to a global list, and then wake up the thread so that it will process
>the stuff. Depending on what you need to do, you can either use a thread
>or a tasklet. I think you should prefer tasklets whenever possible, but
>kernel experts of the list will confirm or infirm this.
>
>Here some sort of pseudo-code (no error checks, never compiled, may be
>completely wrong):
>
>struct job_description {
> /* Here you have the values you need to process your job */
>};
>
>semaphore_t thread_sem;
>struct job_description *job_list;
>spinlock_t job_list_lock;
>
>void my_thread (void *) {
>
> while (1) {
> struct job_description *job;
> struct job_description *local_job_list;
>
> /* Wait to be woken up by interrupt handler */
> sem_down_interruptible (& thread_sem);
>
> /* Get a local pointer to the list, and release the
> spinlock as sooas possible, so that the interrupt
> handler can add more jobs to the global list. */
> spinlock_lock (& job_list_lock);
> local_job_list = job_list;
> job_list = NULL;
> spinlock_unlock (& job_list_lock);
>
> /* Do the job, and free the structures */
> list_for_each_safe (local_job_list, job) {
> /* Do what you need with the job, with the data in
> the 'job' structure */
> list_remove (job);
> kfree (job);
> }
> }
>}
>
>int interrupt_handler (int num) {
> struct job_description *job;
>
> /* Fetch your info */
>
> /* Allocate job description structure */
> job = kmalloc (sizeof(struct job_description), GFP_ATOMIC);
>
> job->... = ...
> job->... = ...
>
> /* Add job to the global list */
> spinlock_lock (& job_list_lock);
> list_add_tail (job_list, job);
> spinlock_unlock (& job_list_lock);
>
> /* Wake up the thread */
> sem_up (& thread_sem);
>}
>
>int module_init (void) {
> sem_init (& thread_sem);
> spinlock_init (& job_list_lock);
> kernel_thread (my_thread);
> return 0;
>}
>
>Here we go.
>
>Thomas
>--
>PETAZZONI Thomas - thomas.petazzoni@xxxxxxxx
>http://thomas.enix.org - Jabber: thomas.petazzoni@xxxxxxxxx
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