minix/kernel/system/do_nice.c
Ben Gras 6f77685609 Split of architecture-dependent and -independent functions for i386,
mainly in the kernel and headers. This split based on work by
Ingmar Alting <iaalting@cs.vu.nl> done for his Minix PowerPC architecture
port.

 . kernel does not program the interrupt controller directly, do any
   other architecture-dependent operations, or contain assembly any more,
   but uses architecture-dependent functions in arch/$(ARCH)/.
 . architecture-dependent constants and types defined in arch/$(ARCH)/include.
 . <ibm/portio.h> moved to <minix/portio.h>, as they have become, for now,
   architecture-independent functions.
 . int86, sdevio, readbios, and iopenable are now i386-specific kernel calls
   and live in arch/i386/do_* now.
 . i386 arch now supports even less 86 code; e.g. mpx86.s and klib86.s have
   gone, and 'machine.protected' is gone (and always taken to be 1 in i386).
   If 86 support is to return, it should be a new architecture.
 . prototypes for the architecture-dependent functions defined in
   kernel/arch/$(ARCH)/*.c but used in kernel/ are in kernel/proto.h
 . /etc/make.conf included in makefiles and shell scripts that need to
   know the building architecture; it defines ARCH=<arch>, currently only
   i386.
 . some basic per-architecture build support outside of the kernel (lib)
 . in clock.c, only dequeue a process if it was ready
 . fixes for new include files

files deleted:
 . mpx/klib.s - only for choosing between mpx/klib86 and -386
 . klib86.s - only for 86

i386-specific files files moved (or arch-dependent stuff moved) to arch/i386/:
 . mpx386.s (entry point)
 . klib386.s
 . sconst.h
 . exception.c
 . protect.c
 . protect.h
 . i8269.c
2006-12-22 15:22:27 +00:00

62 lines
1.9 KiB
C

/* The kernel call implemented in this file:
* m_type: SYS_NICE
*
* The parameters for this kernel call are:
* m1_i1: PR_ENDPT process number to change priority
* m1_i2: PR_PRIORITY the new priority
*/
#include "../system.h"
#include <minix/type.h>
#include <sys/resource.h>
#if USE_NICE
/*===========================================================================*
* do_nice *
*===========================================================================*/
PUBLIC int do_nice(message *m_ptr)
{
/* Change process priority or stop the process. */
int proc_nr, pri, new_q ;
register struct proc *rp;
/* Extract the message parameters and do sanity checking. */
if(!isokendpt(m_ptr->PR_ENDPT, &proc_nr)) return EINVAL;
if (iskerneln(proc_nr)) return(EPERM);
pri = m_ptr->PR_PRIORITY;
rp = proc_addr(proc_nr);
if (pri == PRIO_STOP) {
/* Take process off the scheduling queues. */
if(rp->p_rts_flags == 0) lock_dequeue(rp);
rp->p_rts_flags |= NO_PRIORITY;
return(OK);
}
else if (pri >= PRIO_MIN && pri <= PRIO_MAX) {
/* The value passed in is currently between PRIO_MIN and PRIO_MAX.
* We have to scale this between MIN_USER_Q and MAX_USER_Q to match
* the kernel's scheduling queues.
*/
new_q = MAX_USER_Q + (pri-PRIO_MIN) * (MIN_USER_Q-MAX_USER_Q+1) /
(PRIO_MAX-PRIO_MIN+1);
if (new_q < MAX_USER_Q) new_q = MAX_USER_Q; /* shouldn't happen */
if (new_q > MIN_USER_Q) new_q = MIN_USER_Q; /* shouldn't happen */
/* Make sure the process is not running while changing its priority.
* Put the process back in its new queue if it is runnable.
*/
if(rp->p_rts_flags == 0) lock_dequeue(rp);
rp->p_rts_flags &= ~NO_PRIORITY;
rp->p_max_priority = rp->p_priority = new_q;
if (! rp->p_rts_flags) lock_enqueue(rp);
return(OK);
}
return(EINVAL);
}
#endif /* USE_NICE */