RE: SMP kernel

["B Srinivas " <b.srinivas@xxxxxxxxxxxx>]

-----Original Message-----




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From: Gaurav Dhiman [mailto:gaurav4lkg@xxxxxxxxx] 
Sent: Wednesday, April 27, 2005 6:42 PM
To: B Srinivas 
Cc: kernelnewbies@xxxxxxxxxxxx
Subject: Re: SMP kernel

can you post your code on this list (if possible), so that we can see
what exactly is being done.

-gd


On 4/27/05, B Srinivas <b.srinivas@xxxxxxxxxxxx> wrote:
>  
>  
> 
> Hello there, 
> 
>                  I have written a module which registers a character
device
> . and in the open function I put it into a wait queue
> (interruptible_sleep_on). 
> 
> I load one more module which also registers the character device and
in its
> open fuction I wake the first process in sleep. (wake_up). 
> 
> Here am successfully able to wake up only on a UP kernel and not on a
SMP
> kernel !!!  whats are the fundaments am missing ? 
> 
>   
> 
> Thanks with regards 
> 
> Srinivas Bakki 
> 
>   
> 


Mod.h :

int mod_open(struct inode * , struct file *);
int mod_release(struct inode * , struct file *);

wait_queue_head_t wait;

struct file_operations file_ops={
       open:mod_open,
       release:mod_release,
};







Mod.c :

#define __KERNEL__
#define MODULE


#include<linux/kernel.h>
#include<linux/module.h>

#include<linux/init.h>

#include<linux/fs.h>
#include<asm/current.h>


#include "mod.h"


int mod_open(struct inode * in, struct file * fi)
{
  
  init_waitqueue_head(&wait);
  printk("The process is goin to a sleep state \n");
  interruptible_sleep_on(&wait);
 
return 0;

}

int mod_release(struct inode * in, struct file * fi)
{
 printk("This is the close thing \n");
 
return 0;
}

int load_module(void)
{
  int res;

 
  res = register_chrdev(0,"mod",&file_ops);
  
   
  printk("char dev. registered %d \n",res);
  printk("The module is loaded \n");
  return 0;
}


void unload_module(void)
{
  printk("The module is unloaded \n");
  
}


module_init(load_module);
module_exit(unload_module);




Mod1.c :

#define __KERNEL__
#define MODULE


#include<linux/kernel.h>
#include<linux/module.h>

#include<linux/init.h>

#include<linux/fs.h>

#include "mod.h"




int mod_open(struct inode * in, struct file * fi)
{
 
  
  printk("This is the open thing \n");
  wake_up(&wait);

return 0;

}

int mod_release(struct inode * in, struct file * fi)
{
 printk("This is the close thing \n");
 return 0;
}


int load_module(void)
{
  int res;
  res = register_chrdev(0,"mod1",&file_ops);
  printk("char dev. registered %d \n",res);
  printk("The module is loaded \n");
  return 0;
}


void unload_module(void)
{
  printk("The module is unloaded \n");
  
}


module_init(load_module);
module_exit(unload_module);


Thanks with regards
Srinivas Bakki


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