Hi, I'm implementing a new real time scheduling algorithm in the linux kernel. For that I need to change the default fork() sytem call, so that the new system call takes extra arguments like deadline and execution time while creating the process. In the context of the user process fork() doesn't take any parameters. But in /usr/src/linux-2.4/arch/i386/kernel/process.c , the declaration for the fork() sytem call is like this asmlinkage int sys_fork(struct pt_regs regs). Which library function passes "struct pt_regs" parameter to "sys_fork" after the fork() sytem call is invoked in the user process. Is there any other way I can implement a new system call which behaves as the fork() system call, but can take arguments. It's very urgent for me. Pls help me out regarding this. Seshu. Hi, If your goal is to implement another scheduling algorithm. I think there is no reason for changing the fork system call. The better way is to change few things in sched.c. It is recommended to add a new scheduling policy NOT change the existing ones. If i had to do that, i would add another policy like SCHED_xxxx. And on sched() function check if task's policy is SCHED_xxxx. If it is SCHED_xxxx i would call my function which implements my scheduling algorithm. I would also change sched_setschedular to accept SCHED_xxx value as policy. Which my test application calls to switch another scheduling policy. In this way you need to change least thing. regards manish -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
