patch-2.3.32 linux/kernel/timer.c

• Lines: 792
• Date: Mon Dec 13 16:13:36 1999
• Orig file: v2.3.31/linux/kernel/timer.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.31/linux/kernel/timer.c linux/kernel/timer.c
@@ -0,0 +1,791 @@
+/*
+ *  linux/kernel/timer.c
+ *
+ *  Kernel internal timers, kernel timekeeping, basic process system calls
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  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
+ *  1998-12-24  Fixed a xtime SMP race (we need the xtime_lock rw spinlock to
+ *              serialize accesses to xtime/lost_ticks).
+ *                              Copyright (C) 1998  Andrea Arcangeli
+ *  1999-03-10  Improved NTP compatibility by Ulrich Windl
+ */
+
+#include <linux/mm.h>
+#include <linux/timex.h>
+#include <linux/delay.h>
+#include <linux/smp_lock.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+
+#include <asm/uaccess.h>
+
+/*
+ * Timekeeping variables
+ */
+
+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 long volatile jiffies = 0;
+
+unsigned int * prof_buffer = NULL;
+unsigned long prof_len = 0;
+unsigned long prof_shift = 0;
+
+/*
+ * 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;
+}
+
+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];
+
+/*
+ * 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
+}
+
+/*
+ * 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;
+}
+
+/*
+ * 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 };
+
+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);
+	}
+}
+
+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);
+}
+
+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;
+}
+
+#endif
+
+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;
+}
+