patch-2.3.32 linux/kernel/sched.c

• Lines: 839
• Date: Fri Dec 10 14:57:11 1999
• Orig file: v2.3.31/linux/kernel/sched.c
• Orig date: Tue Dec 7 09:32:52 1999

diff -u --recursive --new-file v2.3.31/linux/kernel/sched.c linux/kernel/sched.c
@@ -1,20 +1,15 @@
 /*
  *  linux/kernel/sched.c
  *
+ *  Kernel scheduler and related syscalls
+ *
  *  Copyright (C) 1991, 1992  Linus Torvalds
  *
  *  1996-12-23  Modified by Dave Grothe to fix bugs in semaphores and
  *              make semaphores SMP safe
- *  1997-01-28  Modified by Finn Arne Gangstad to make timers scale better.
- *  1997-09-10	Updated NTP code according to technical memorandum Jan '96
- *		"A Kernel Model for Precision Timekeeping" by Dave Mills
  *  1998-11-19	Implemented schedule_timeout() and related stuff
  *		by Andrea Arcangeli
- *  1998-12-24	Fixed a xtime SMP race (we need the xtime_lock rw spinlock to
- *		serialize accesses to xtime/lost_ticks).
- *				Copyright (C) 1998  Andrea Arcangeli
  *  1998-12-28  Implemented better SMP scheduling by Ingo Molnar
- *  1999-03-10	Improved NTP compatibility by Ulrich Windl
  */
 
 /*
@@ -25,69 +20,27 @@
  */
 
 #include <linux/mm.h>
-#include <linux/kernel_stat.h>
-#include <linux/fdreg.h>
-#include <linux/delay.h>
-#include <linux/interrupt.h>
-#include <linux/smp_lock.h>
 #include <linux/init.h>
+#include <linux/smp_lock.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
 
-#include <asm/io.h>
 #include <asm/uaccess.h>
-#include <asm/pgtable.h>
 #include <asm/mmu_context.h>
 
-#include <linux/timex.h>
+
+extern void timer_bh(void);
+extern void tqueue_bh(void);
+extern void immediate_bh(void);
 
 /*
- * kernel variables
+ * scheduler variables
  */
 
 unsigned securebits = SECUREBITS_DEFAULT; /* systemwide security settings */
 
-long tick = (1000000 + HZ/2) / HZ;	/* timer interrupt period */
-
-/* The current time */
-volatile struct timeval xtime __attribute__ ((aligned (16)));
-
-/* Don't completely fail for HZ > 500.  */
-int tickadj = 500/HZ ? : 1;		/* microsecs */
-
-DECLARE_TASK_QUEUE(tq_timer);
-DECLARE_TASK_QUEUE(tq_immediate);
-DECLARE_TASK_QUEUE(tq_scheduler);
-
-/*
- * phase-lock loop variables
- */
-/* TIME_ERROR prevents overwriting the CMOS clock */
-int time_state = TIME_OK;	/* clock synchronization status */
-int time_status = STA_UNSYNC;	/* clock status bits */
-long time_offset = 0;		/* time adjustment (us) */
-long time_constant = 2;		/* pll time constant */
-long time_tolerance = MAXFREQ;	/* frequency tolerance (ppm) */
-long time_precision = 1;	/* clock precision (us) */
-long time_maxerror = NTP_PHASE_LIMIT;	/* maximum error (us) */
-long time_esterror = NTP_PHASE_LIMIT;	/* estimated error (us) */
-long time_phase = 0;		/* phase offset (scaled us) */
-long time_freq = ((1000000 + HZ/2) % HZ - HZ/2) << SHIFT_USEC;	/* frequency offset (scaled ppm) */
-long time_adj = 0;		/* tick adjust (scaled 1 / HZ) */
-long time_reftime = 0;		/* time at last adjustment (s) */
-
-long time_adjust = 0;
-long time_adjust_step = 0;
-
-unsigned long event = 0;
-
-extern int do_setitimer(int, struct itimerval *, struct itimerval *);
-unsigned int * prof_buffer = NULL;
-unsigned long prof_len = 0;
-unsigned long prof_shift = 0;
-
 extern void mem_use(void);
 
-unsigned long volatile jiffies=0;
-
 /*
  *	Init task must be ok at boot for the ix86 as we will check its signals
  *	via the SMP irq return path.
@@ -398,139 +351,6 @@
 	wake_up_process(p);
 }
 
-/*
- * Event timer code
- */
-#define TVN_BITS 6
-#define TVR_BITS 8
-#define TVN_SIZE (1 << TVN_BITS)
-#define TVR_SIZE (1 << TVR_BITS)
-#define TVN_MASK (TVN_SIZE - 1)
-#define TVR_MASK (TVR_SIZE - 1)
-
-struct timer_vec {
-        int index;
-        struct timer_list *vec[TVN_SIZE];
-};
-
-struct timer_vec_root {
-        int index;
-        struct timer_list *vec[TVR_SIZE];
-};
-
-static struct timer_vec tv5 = { 0 };
-static struct timer_vec tv4 = { 0 };
-static struct timer_vec tv3 = { 0 };
-static struct timer_vec tv2 = { 0 };
-static struct timer_vec_root tv1 = { 0 };
-
-static struct timer_vec * const tvecs[] = {
-	(struct timer_vec *)&tv1, &tv2, &tv3, &tv4, &tv5
-};
-
-#define NOOF_TVECS (sizeof(tvecs) / sizeof(tvecs[0]))
-
-static unsigned long timer_jiffies = 0;
-
-static inline void insert_timer(struct timer_list *timer,
-				struct timer_list **vec, int idx)
-{
-	if ((timer->next = vec[idx]))
-		vec[idx]->prev = timer;
-	vec[idx] = timer;
-	timer->prev = (struct timer_list *)&vec[idx];
-}
-
-static inline void internal_add_timer(struct timer_list *timer)
-{
-	/*
-	 * must be cli-ed when calling this
-	 */
-	unsigned long expires = timer->expires;
-	unsigned long idx = expires - timer_jiffies;
-
-	if (idx < TVR_SIZE) {
-		int i = expires & TVR_MASK;
-		insert_timer(timer, tv1.vec, i);
-	} else if (idx < 1 << (TVR_BITS + TVN_BITS)) {
-		int i = (expires >> TVR_BITS) & TVN_MASK;
-		insert_timer(timer, tv2.vec, i);
-	} else if (idx < 1 << (TVR_BITS + 2 * TVN_BITS)) {
-		int i = (expires >> (TVR_BITS + TVN_BITS)) & TVN_MASK;
-		insert_timer(timer, tv3.vec, i);
-	} else if (idx < 1 << (TVR_BITS + 3 * TVN_BITS)) {
-		int i = (expires >> (TVR_BITS + 2 * TVN_BITS)) & TVN_MASK;
-		insert_timer(timer, tv4.vec, i);
-	} else if ((signed long) idx < 0) {
-		/* can happen if you add a timer with expires == jiffies,
-		 * or you set a timer to go off in the past
-		 */
-		insert_timer(timer, tv1.vec, tv1.index);
-	} else if (idx <= 0xffffffffUL) {
-		int i = (expires >> (TVR_BITS + 3 * TVN_BITS)) & TVN_MASK;
-		insert_timer(timer, tv5.vec, i);
-	} else {
-		/* Can only get here on architectures with 64-bit jiffies */
-		timer->next = timer->prev = timer;
-	}
-}
-
-spinlock_t timerlist_lock = SPIN_LOCK_UNLOCKED;
-
-void add_timer(struct timer_list *timer)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&timerlist_lock, flags);
-	if (timer->prev)
-		goto bug;
-	internal_add_timer(timer);
-out:
-	spin_unlock_irqrestore(&timerlist_lock, flags);
-	return;
-
-bug:
-	printk("bug: kernel timer added twice at %p.\n",
-			__builtin_return_address(0));
-	goto out;
-}
-
-static inline int detach_timer(struct timer_list *timer)
-{
-	struct timer_list *prev = timer->prev;
-	if (prev) {
-		struct timer_list *next = timer->next;
-		prev->next = next;
-		if (next)
-			next->prev = prev;
-		return 1;
-	}
-	return 0;
-}
-
-void mod_timer(struct timer_list *timer, unsigned long expires)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&timerlist_lock, flags);
-	timer->expires = expires;
-	detach_timer(timer);
-	internal_add_timer(timer);
-	spin_unlock_irqrestore(&timerlist_lock, flags);
-}
-
-int del_timer(struct timer_list * timer)
-{
-	int ret;
-	unsigned long flags;
-
-	spin_lock_irqsave(&timerlist_lock, flags);
-	ret = detach_timer(timer);
-	timer->next = timer->prev = 0;
-	spin_unlock_irqrestore(&timerlist_lock, flags);
-	return ret;
-}
-
 signed long schedule_timeout(signed long timeout)
 {
 	struct timer_list timer;
@@ -944,549 +764,9 @@
 
 void scheduling_functions_end_here(void) { }
 
-static inline void cascade_timers(struct timer_vec *tv)
-{
-        /* cascade all the timers from tv up one level */
-        struct timer_list *timer;
-        timer = tv->vec[tv->index];
-        /*
-         * We are removing _all_ timers from the list, so we don't  have to
-         * detach them individually, just clear the list afterwards.
-         */
-        while (timer) {
-                struct timer_list *tmp = timer;
-                timer = timer->next;
-                internal_add_timer(tmp);
-        }
-        tv->vec[tv->index] = NULL;
-        tv->index = (tv->index + 1) & TVN_MASK;
-}
-
-static inline void run_timer_list(void)
-{
-	spin_lock_irq(&timerlist_lock);
-	while ((long)(jiffies - timer_jiffies) >= 0) {
-		struct timer_list *timer;
-		if (!tv1.index) {
-			int n = 1;
-			do {
-				cascade_timers(tvecs[n]);
-			} while (tvecs[n]->index == 1 && ++n < NOOF_TVECS);
-		}
-		while ((timer = tv1.vec[tv1.index])) {
-			void (*fn)(unsigned long) = timer->function;
-			unsigned long data = timer->data;
-			detach_timer(timer);
-			timer->next = timer->prev = NULL;
-			spin_unlock_irq(&timerlist_lock);
-			fn(data);
-			spin_lock_irq(&timerlist_lock);
-		}
-		++timer_jiffies; 
-		tv1.index = (tv1.index + 1) & TVR_MASK;
-	}
-	spin_unlock_irq(&timerlist_lock);
-}
-
-
-static inline void run_old_timers(void)
-{
-	struct timer_struct *tp;
-	unsigned long mask;
-
-	for (mask = 1, tp = timer_table+0 ; mask ; tp++,mask += mask) {
-		if (mask > timer_active)
-			break;
-		if (!(mask & timer_active))
-			continue;
-		if (time_after(tp->expires, jiffies))
-			continue;
-		timer_active &= ~mask;
-		tp->fn();
-		sti();
-	}
-}
-
-spinlock_t tqueue_lock = SPIN_LOCK_UNLOCKED;
-
-void tqueue_bh(void)
-{
-	run_task_queue(&tq_timer);
-}
-
-void immediate_bh(void)
-{
-	run_task_queue(&tq_immediate);
-}
-
-unsigned long timer_active = 0;
-struct timer_struct timer_table[32];
-
-/*
- * Hmm.. Changed this, as the GNU make sources (load.c) seems to
- * imply that avenrun[] is the standard name for this kind of thing.
- * Nothing else seems to be standardized: the fractional size etc
- * all seem to differ on different machines.
- */
-unsigned long avenrun[3] = { 0,0,0 };
-
-/*
- * Nr of active tasks - counted in fixed-point numbers
- */
-static unsigned long count_active_tasks(void)
-{
-	struct task_struct *p;
-	unsigned long nr = 0;
-
-	read_lock(&tasklist_lock);
-	for_each_task(p) {
-		if ((p->state == TASK_RUNNING ||
-		     (p->state & TASK_UNINTERRUPTIBLE) ||
-		     (p->state & TASK_SWAPPING)))
-			nr += FIXED_1;
-	}
-	read_unlock(&tasklist_lock);
-	return nr;
-}
-
-static inline void calc_load(unsigned long ticks)
-{
-	unsigned long active_tasks; /* fixed-point */
-	static int count = LOAD_FREQ;
-
-	count -= ticks;
-	if (count < 0) {
-		count += LOAD_FREQ;
-		active_tasks = count_active_tasks();
-		CALC_LOAD(avenrun[0], EXP_1, active_tasks);
-		CALC_LOAD(avenrun[1], EXP_5, active_tasks);
-		CALC_LOAD(avenrun[2], EXP_15, active_tasks);
-	}
-}
-
-/*
- * this routine handles the overflow of the microsecond field
- *
- * The tricky bits of code to handle the accurate clock support
- * were provided by Dave Mills (Mills@UDEL.EDU) of NTP fame.
- * They were originally developed for SUN and DEC kernels.
- * All the kudos should go to Dave for this stuff.
- *
- */
-static void second_overflow(void)
-{
-    long ltemp;
-
-    /* Bump the maxerror field */
-    time_maxerror += time_tolerance >> SHIFT_USEC;
-    if ( time_maxerror > NTP_PHASE_LIMIT ) {
-        time_maxerror = NTP_PHASE_LIMIT;
-	time_status |= STA_UNSYNC;
-    }
-
-    /*
-     * Leap second processing. If in leap-insert state at
-     * the end of the day, the system clock is set back one
-     * second; if in leap-delete state, the system clock is
-     * set ahead one second. The microtime() routine or
-     * external clock driver will insure that reported time
-     * is always monotonic. The ugly divides should be
-     * replaced.
-     */
-    switch (time_state) {
-
-    case TIME_OK:
-	if (time_status & STA_INS)
-	    time_state = TIME_INS;
-	else if (time_status & STA_DEL)
-	    time_state = TIME_DEL;
-	break;
-
-    case TIME_INS:
-	if (xtime.tv_sec % 86400 == 0) {
-	    xtime.tv_sec--;
-	    time_state = TIME_OOP;
-	    printk(KERN_NOTICE "Clock: inserting leap second 23:59:60 UTC\n");
-	}
-	break;
-
-    case TIME_DEL:
-	if ((xtime.tv_sec + 1) % 86400 == 0) {
-	    xtime.tv_sec++;
-	    time_state = TIME_WAIT;
-	    printk(KERN_NOTICE "Clock: deleting leap second 23:59:59 UTC\n");
-	}
-	break;
-
-    case TIME_OOP:
-	time_state = TIME_WAIT;
-	break;
-
-    case TIME_WAIT:
-	if (!(time_status & (STA_INS | STA_DEL)))
-	    time_state = TIME_OK;
-    }
-
-    /*
-     * Compute the phase adjustment for the next second. In
-     * PLL mode, the offset is reduced by a fixed factor
-     * times the time constant. In FLL mode the offset is
-     * used directly. In either mode, the maximum phase
-     * adjustment for each second is clamped so as to spread
-     * the adjustment over not more than the number of
-     * seconds between updates.
-     */
-    if (time_offset < 0) {
-	ltemp = -time_offset;
-	if (!(time_status & STA_FLL))
-	    ltemp >>= SHIFT_KG + time_constant;
-	if (ltemp > (MAXPHASE / MINSEC) << SHIFT_UPDATE)
-	    ltemp = (MAXPHASE / MINSEC) << SHIFT_UPDATE;
-	time_offset += ltemp;
-	time_adj = -ltemp << (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE);
-    } else {
-	ltemp = time_offset;
-	if (!(time_status & STA_FLL))
-	    ltemp >>= SHIFT_KG + time_constant;
-	if (ltemp > (MAXPHASE / MINSEC) << SHIFT_UPDATE)
-	    ltemp = (MAXPHASE / MINSEC) << SHIFT_UPDATE;
-	time_offset -= ltemp;
-	time_adj = ltemp << (SHIFT_SCALE - SHIFT_HZ - SHIFT_UPDATE);
-    }
-
-    /*
-     * Compute the frequency estimate and additional phase
-     * adjustment due to frequency error for the next
-     * second. When the PPS signal is engaged, gnaw on the
-     * watchdog counter and update the frequency computed by
-     * the pll and the PPS signal.
-     */
-    pps_valid++;
-    if (pps_valid == PPS_VALID) {	/* PPS signal lost */
-	pps_jitter = MAXTIME;
-	pps_stabil = MAXFREQ;
-	time_status &= ~(STA_PPSSIGNAL | STA_PPSJITTER |
-			 STA_PPSWANDER | STA_PPSERROR);
-    }
-    ltemp = time_freq + pps_freq;
-    if (ltemp < 0)
-	time_adj -= -ltemp >>
-	    (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE);
-    else
-	time_adj += ltemp >>
-	    (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE);
-
-#if HZ == 100
-    /* Compensate for (HZ==100) != (1 << SHIFT_HZ).
-     * Add 25% and 3.125% to get 128.125; => only 0.125% error (p. 14)
-     */
-    if (time_adj < 0)
-	time_adj -= (-time_adj >> 2) + (-time_adj >> 5);
-    else
-	time_adj += (time_adj >> 2) + (time_adj >> 5);
-#endif
-}
-
-/* in the NTP reference this is called "hardclock()" */
-static void update_wall_time_one_tick(void)
-{
-	if ( (time_adjust_step = time_adjust) != 0 ) {
-	    /* We are doing an adjtime thing. 
-	     *
-	     * Prepare time_adjust_step to be within bounds.
-	     * Note that a positive time_adjust means we want the clock
-	     * to run faster.
-	     *
-	     * Limit the amount of the step to be in the range
-	     * -tickadj .. +tickadj
-	     */
-	     if (time_adjust > tickadj)
-		time_adjust_step = tickadj;
-	     else if (time_adjust < -tickadj)
-		time_adjust_step = -tickadj;
-	     
-	    /* Reduce by this step the amount of time left  */
-	    time_adjust -= time_adjust_step;
-	}
-	xtime.tv_usec += tick + time_adjust_step;
-	/*
-	 * Advance the phase, once it gets to one microsecond, then
-	 * advance the tick more.
-	 */
-	time_phase += time_adj;
-	if (time_phase <= -FINEUSEC) {
-		long ltemp = -time_phase >> SHIFT_SCALE;
-		time_phase += ltemp << SHIFT_SCALE;
-		xtime.tv_usec -= ltemp;
-	}
-	else if (time_phase >= FINEUSEC) {
-		long ltemp = time_phase >> SHIFT_SCALE;
-		time_phase -= ltemp << SHIFT_SCALE;
-		xtime.tv_usec += ltemp;
-	}
-}
-
-/*
- * Using a loop looks inefficient, but "ticks" is
- * usually just one (we shouldn't be losing ticks,
- * we're doing this this way mainly for interrupt
- * latency reasons, not because we think we'll
- * have lots of lost timer ticks
- */
-static void update_wall_time(unsigned long ticks)
-{
-	do {
-		ticks--;
-		update_wall_time_one_tick();
-	} while (ticks);
-
-	if (xtime.tv_usec >= 1000000) {
-	    xtime.tv_usec -= 1000000;
-	    xtime.tv_sec++;
-	    second_overflow();
-	}
-}
-
-static inline void do_process_times(struct task_struct *p,
-	unsigned long user, unsigned long system)
-{
-	unsigned long psecs;
-
-	psecs = (p->times.tms_utime += user);
-	psecs += (p->times.tms_stime += system);
-	if (psecs / HZ > p->rlim[RLIMIT_CPU].rlim_cur) {
-		/* Send SIGXCPU every second.. */
-		if (!(psecs % HZ))
-			send_sig(SIGXCPU, p, 1);
-		/* and SIGKILL when we go over max.. */
-		if (psecs / HZ > p->rlim[RLIMIT_CPU].rlim_max)
-			send_sig(SIGKILL, p, 1);
-	}
-}
-
-static inline void do_it_virt(struct task_struct * p, unsigned long ticks)
-{
-	unsigned long it_virt = p->it_virt_value;
-
-	if (it_virt) {
-		if (it_virt <= ticks) {
-			it_virt = ticks + p->it_virt_incr;
-			send_sig(SIGVTALRM, p, 1);
-		}
-		p->it_virt_value = it_virt - ticks;
-	}
-}
-
-static inline void do_it_prof(struct task_struct * p, unsigned long ticks)
-{
-	unsigned long it_prof = p->it_prof_value;
-
-	if (it_prof) {
-		if (it_prof <= ticks) {
-			it_prof = ticks + p->it_prof_incr;
-			send_sig(SIGPROF, p, 1);
-		}
-		p->it_prof_value = it_prof - ticks;
-	}
-}
-
-void update_one_process(struct task_struct *p,
-	unsigned long ticks, unsigned long user, unsigned long system, int cpu)
-{
-	p->per_cpu_utime[cpu] += user;
-	p->per_cpu_stime[cpu] += system;
-	do_process_times(p, user, system);
-	do_it_virt(p, user);
-	do_it_prof(p, ticks);
-}	
-
-static void update_process_times(unsigned long ticks, unsigned long system)
-{
-/*
- * SMP does this on a per-CPU basis elsewhere
- */
-#ifndef  __SMP__
-	struct task_struct * p = current;
-	unsigned long user = ticks - system;
-	if (p->pid) {
-		p->counter -= ticks;
-		if (p->counter <= 0) {
-			p->counter = 0;
-			p->need_resched = 1;
-		}
-		if (p->priority < DEF_PRIORITY)
-			kstat.cpu_nice += user;
-		else
-			kstat.cpu_user += user;
-		kstat.cpu_system += system;
-	}
-	update_one_process(p, ticks, user, system, 0);
-#endif
-}
-
-volatile unsigned long lost_ticks = 0;
-static unsigned long lost_ticks_system = 0;
-
-/*
- * This spinlock protect us from races in SMP while playing with xtime. -arca
- */
-rwlock_t xtime_lock = RW_LOCK_UNLOCKED;
-
-static inline void update_times(void)
-{
-	unsigned long ticks;
-
-	/*
-	 * update_times() is run from the raw timer_bh handler so we
-	 * just know that the irqs are locally enabled and so we don't
-	 * need to save/restore the flags of the local CPU here. -arca
-	 */
-	write_lock_irq(&xtime_lock);
-
-	ticks = lost_ticks;
-	lost_ticks = 0;
-
-	if (ticks) {
-		unsigned long system;
-		system = xchg(&lost_ticks_system, 0);
-
-		calc_load(ticks);
-		update_wall_time(ticks);
-		write_unlock_irq(&xtime_lock);
-		
-		update_process_times(ticks, system);
-
-	} else
-		write_unlock_irq(&xtime_lock);
-}
-
-static void timer_bh(void)
-{
-	update_times();
-	run_old_timers();
-	run_timer_list();
-}
-
-void do_timer(struct pt_regs * regs)
-{
-	(*(unsigned long *)&jiffies)++;
-	lost_ticks++;
-	mark_bh(TIMER_BH);
-	if (!user_mode(regs))
-		lost_ticks_system++;
-	if (tq_timer)
-		mark_bh(TQUEUE_BH);
-}
-
-#if !defined(__alpha__) && !defined(__ia64__)
-
-/*
- * For backwards compatibility?  This can be done in libc so Alpha
- * and all newer ports shouldn't need it.
- */
-asmlinkage unsigned long sys_alarm(unsigned int seconds)
-{
-	struct itimerval it_new, it_old;
-	unsigned int oldalarm;
-
-	it_new.it_interval.tv_sec = it_new.it_interval.tv_usec = 0;
-	it_new.it_value.tv_sec = seconds;
-	it_new.it_value.tv_usec = 0;
-	do_setitimer(ITIMER_REAL, &it_new, &it_old);
-	oldalarm = it_old.it_value.tv_sec;
-	/* ehhh.. We can't return 0 if we have an alarm pending.. */
-	/* And we'd better return too much than too little anyway */
-	if (it_old.it_value.tv_usec)
-		oldalarm++;
-	return oldalarm;
-}
-
-#endif
-
 #ifndef __alpha__
 
 /*
- * The Alpha uses getxpid, getxuid, and getxgid instead.  Maybe this
- * should be moved into arch/i386 instead?
- */
- 
-asmlinkage long sys_getpid(void)
-{
-	/* This is SMP safe - current->pid doesn't change */
-	return current->pid;
-}
-
-/*
- * This is not strictly SMP safe: p_opptr could change
- * from under us. However, rather than getting any lock
- * we can use an optimistic algorithm: get the parent
- * pid, and go back and check that the parent is still
- * the same. If it has changed (which is extremely unlikely
- * indeed), we just try again..
- *
- * NOTE! This depends on the fact that even if we _do_
- * get an old value of "parent", we can happily dereference
- * the pointer: we just can't necessarily trust the result
- * until we know that the parent pointer is valid.
- *
- * The "mb()" macro is a memory barrier - a synchronizing
- * event. It also makes sure that gcc doesn't optimize
- * away the necessary memory references.. The barrier doesn't
- * have to have all that strong semantics: on x86 we don't
- * really require a synchronizing instruction, for example.
- * The barrier is more important for code generation than
- * for any real memory ordering semantics (even if there is
- * a small window for a race, using the old pointer is
- * harmless for a while).
- */
-asmlinkage long sys_getppid(void)
-{
-	int pid;
-	struct task_struct * me = current;
-	struct task_struct * parent;
-
-	parent = me->p_opptr;
-	for (;;) {
-		pid = parent->pid;
-#if __SMP__
-{
-		struct task_struct *old = parent;
-		mb();
-		parent = me->p_opptr;
-		if (old != parent)
-			continue;
-}
-#endif
-		break;
-	}
-	return pid;
-}
-
-asmlinkage long sys_getuid(void)
-{
-	/* Only we change this so SMP safe */
-	return current->uid;
-}
-
-asmlinkage long sys_geteuid(void)
-{
-	/* Only we change this so SMP safe */
-	return current->euid;
-}
-
-asmlinkage long sys_getgid(void)
-{
-	/* Only we change this so SMP safe */
-	return current->gid;
-}
-
-asmlinkage long sys_getegid(void)
-{
-	/* Only we change this so SMP safe */
-	return  current->egid;
-}
-
-/*
  * This has been replaced by sys_setpriority.  Maybe it should be
  * moved into the arch dependent tree for those ports that require
  * it for backward compatibility?
@@ -1739,47 +1019,6 @@
 	t.tv_nsec = 150000;
 	if (copy_to_user(interval, &t, sizeof(struct timespec)))
 		return -EFAULT;
-	return 0;
-}
-
-asmlinkage long sys_nanosleep(struct timespec *rqtp, struct timespec *rmtp)
-{
-	struct timespec t;
-	unsigned long expire;
-
-	if(copy_from_user(&t, rqtp, sizeof(struct timespec)))
-		return -EFAULT;
-
-	if (t.tv_nsec >= 1000000000L || t.tv_nsec < 0 || t.tv_sec < 0)
-		return -EINVAL;
-
-
-	if (t.tv_sec == 0 && t.tv_nsec <= 2000000L &&
-	    current->policy != SCHED_OTHER)
-	{
-		/*
-		 * Short delay requests up to 2 ms will be handled with
-		 * high precision by a busy wait for all real-time processes.
-		 *
-		 * Its important on SMP not to do this holding locks.
-		 */
-		udelay((t.tv_nsec + 999) / 1000);
-		return 0;
-	}
-
-	expire = timespec_to_jiffies(&t) + (t.tv_sec || t.tv_nsec);
-
-	current->state = TASK_INTERRUPTIBLE;
-	expire = schedule_timeout(expire);
-
-	if (expire) {
-		if (rmtp) {
-			jiffies_to_timespec(expire, &t);
-			if (copy_to_user(rmtp, &t, sizeof(struct timespec)))
-				return -EFAULT;
-		}
-		return -EINTR;
-	}
 	return 0;
 }