[PATCH] kill wall_jiffies

With 2.6.18-rc4-mm2, now wall_jiffies will always be the same as jiffies.
So we can kill wall_jiffies completely.

This is just a cleanup and logically should not change any real behavior
except for one thing: RTC updating code in (old) ppc and xtensa use a
condition "jiffies - wall_jiffies == 1".  This condition is never met so I
suppose it is just a bug.  I just remove that condition only instead of
kill the whole "if" block.

[heiko.carstens@de.ibm.com: s390 build fix and cleanup]
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Andi Kleen <ak@muc.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Hirokazu Takata <takata.hirokazu@renesas.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/alpha/kernel/time.c

@@ -54,8 +54,6 @@
 #include "proto.h"
 #include "irq_impl.h"
 
-extern unsigned long wall_jiffies;	/* kernel/timer.c */
-
 static int set_rtc_mmss(unsigned long);
 
 DEFINE_SPINLOCK(rtc_lock);
@@ -413,7 +411,7 @@ void
 do_gettimeofday(struct timeval *tv)
 {
 	unsigned long flags;
-	unsigned long sec, usec, lost, seq;
+	unsigned long sec, usec, seq;
 	unsigned long delta_cycles, delta_usec, partial_tick;
 
 	do {
@@ -423,14 +421,13 @@ do_gettimeofday(struct timeval *tv)
 		sec = xtime.tv_sec;
 		usec = (xtime.tv_nsec / 1000);
 		partial_tick = state.partial_tick;
-		lost = jiffies - wall_jiffies;
 
 	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
 
 #ifdef CONFIG_SMP
 	/* Until and unless we figure out how to get cpu cycle counters
 	   in sync and keep them there, we can't use the rpcc tricks.  */
-	delta_usec = lost * (1000000 / HZ);
+	delta_usec = 0;
 #else
 	/*
 	 * usec = cycles * ticks_per_cycle * 2**48 * 1e6 / (2**48 * ticks)
@@ -446,8 +443,7 @@ do_gettimeofday(struct timeval *tv)
 	 */
 
 	delta_usec = (delta_cycles * state.scaled_ticks_per_cycle 
-		      + partial_tick
-		      + (lost << FIX_SHIFT)) * 15625;
+		      + partial_tick) * 15625;
 	delta_usec = ((delta_usec / ((1UL << (FIX_SHIFT-6-1)) * HZ)) + 1) / 2;
 #endif
 
@@ -480,12 +476,11 @@ do_settimeofday(struct timespec *tv)
 	   time.  Without this, a full-tick error is possible.  */
 
 #ifdef CONFIG_SMP
-	delta_nsec = (jiffies - wall_jiffies) * (NSEC_PER_SEC / HZ);
+	delta_nsec = 0;
 #else
 	delta_nsec = rpcc() - state.last_time;
 	delta_nsec = (delta_nsec * state.scaled_ticks_per_cycle 
-		      + state.partial_tick
-		      + ((jiffies - wall_jiffies) << FIX_SHIFT)) * 15625;
+		      + state.partial_tick) * 15625;
 	delta_nsec = ((delta_nsec / ((1UL << (FIX_SHIFT-6-1)) * HZ)) + 1) / 2;
 	delta_nsec *= 1000;
 #endif

arch/arm/kernel/time.c

@@ -37,8 +37,6 @@
  */
 struct sys_timer *system_timer;
 
-extern unsigned long wall_jiffies;
-
 /* this needs a better home */
 DEFINE_SPINLOCK(rtc_lock);
 
@@ -237,16 +235,11 @@ void do_gettimeofday(struct timeval *tv)
 {
 	unsigned long flags;
 	unsigned long seq;
-	unsigned long usec, sec, lost;
+	unsigned long usec, sec;
 
 	do {
 		seq = read_seqbegin_irqsave(&xtime_lock, flags);
 		usec = system_timer->offset();
-
-		lost = jiffies - wall_jiffies;
-		if (lost)
-			usec += lost * USECS_PER_JIFFY;
-
 		sec = xtime.tv_sec;
 		usec += xtime.tv_nsec / 1000;
 	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
@@ -279,7 +272,6 @@ int do_settimeofday(struct timespec *tv)
 	 * done, and then undo it!
 	 */
 	nsec -= system_timer->offset() * NSEC_PER_USEC;
-	nsec -= (jiffies - wall_jiffies) * TICK_NSEC;
 
 	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
 	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);

arch/arm26/kernel/time.c

@@ -33,8 +33,6 @@
 #include <asm/irq.h>
 #include <asm/ioc.h>
 
-extern unsigned long wall_jiffies;
-
 /* this needs a better home */
 DEFINE_SPINLOCK(rtc_lock);
 
@@ -136,16 +134,11 @@ void do_gettimeofday(struct timeval *tv)
 {
 	unsigned long flags;
 	unsigned long seq;
-	unsigned long usec, sec, lost;
+	unsigned long usec, sec;
 
 	do {
 		seq = read_seqbegin_irqsave(&xtime_lock, flags);
 		usec = gettimeoffset();
-
-		lost = jiffies - wall_jiffies;
-		if (lost)
-			usec += lost * USECS_PER_JIFFY;
-
 		sec = xtime.tv_sec;
 		usec += xtime.tv_nsec / 1000;
 	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
@@ -174,8 +167,7 @@ int do_settimeofday(struct timespec *tv)
 	 * wall time.  Discover what correction gettimeofday() would have
 	 * done, and then undo it!
 	 */
-	tv->tv_nsec -= 1000 * (gettimeoffset() +
-			(jiffies - wall_jiffies) * USECS_PER_JIFFY);
+	tv->tv_nsec -= 1000 * gettimeoffset();
 
 	while (tv->tv_nsec < 0) {
 		tv->tv_nsec += NSEC_PER_SEC;

arch/cris/kernel/time.c

@@ -37,7 +37,6 @@ int have_rtc;  /* used to remember if we have an RTC or not */;
 
 #define TICK_SIZE tick
 
-extern unsigned long wall_jiffies;
 extern unsigned long loops_per_jiffy; /* init/main.c */
 unsigned long loops_per_usec;
 
@@ -58,11 +57,6 @@ void do_gettimeofday(struct timeval *tv)
 	local_irq_save(flags);
 	local_irq_disable();
 	usec = do_gettimeoffset();
-	{
-		unsigned long lost = jiffies - wall_jiffies;
-		if (lost)
-			usec += lost * (1000000 / HZ);
-	}
 
         /*
 	 * If time_adjust is negative then NTP is slowing the clock
@@ -103,7 +97,6 @@ int do_settimeofday(struct timespec *tv)
 	 * made, and then undo it!
 	 */
 	nsec -= do_gettimeoffset() * NSEC_PER_USEC;
-	nsec -= (jiffies - wall_jiffies) * TICK_NSEC;
 
 	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
 	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);

arch/i386/kernel/time.c

@@ -76,8 +76,6 @@ int pit_latch_buggy;              /* extern */
 unsigned int cpu_khz;	/* Detected as we calibrate the TSC */
 EXPORT_SYMBOL(cpu_khz);
 
-extern unsigned long wall_jiffies;
-
 DEFINE_SPINLOCK(rtc_lock);
 EXPORT_SYMBOL(rtc_lock);
 
@@ -329,7 +327,6 @@ static int timer_resume(struct sys_device *dev)
 	do_settimeofday(&ts);
 	write_seqlock_irqsave(&xtime_lock, flags);
 	jiffies_64 += sleep_length;
-	wall_jiffies += sleep_length;
 	write_sequnlock_irqrestore(&xtime_lock, flags);
 	touch_softlockup_watchdog();
 	return 0;

arch/ia64/kernel/time.c

@@ -29,8 +29,6 @@
 #include <asm/sections.h>
 #include <asm/system.h>
 
-extern unsigned long wall_jiffies;
-
 volatile int time_keeper_id = 0; /* smp_processor_id() of time-keeper */
 
 #ifdef CONFIG_IA64_DEBUG_IRQ

arch/m32r/kernel/time.c

@@ -38,7 +38,6 @@ extern void send_IPI_allbutself(int, int);
 extern void smp_local_timer_interrupt(struct pt_regs *);
 #endif
 
-extern unsigned long wall_jiffies;
 #define TICK_SIZE	(tick_nsec / 1000)
 
 /*
@@ -108,24 +107,17 @@ void do_gettimeofday(struct timeval *tv)
 	unsigned long max_ntp_tick = tick_usec - tickadj;
 
 	do {
-		unsigned long lost;
-
 		seq = read_seqbegin(&xtime_lock);
 
 		usec = do_gettimeoffset();
-		lost = jiffies - wall_jiffies;
 
 		/*
 		 * If time_adjust is negative then NTP is slowing the clock
 		 * so make sure not to go into next possible interval.
 		 * Better to lose some accuracy than have time go backwards..
 		 */
-		if (unlikely(time_adjust < 0)) {
+		if (unlikely(time_adjust < 0))
 			usec = min(usec, max_ntp_tick);
-			if (lost)
-				usec += lost * max_ntp_tick;
-		} else if (unlikely(lost))
-			usec += lost * tick_usec;
 
 		sec = xtime.tv_sec;
 		usec += (xtime.tv_nsec / 1000);
@@ -158,7 +150,6 @@ int do_settimeofday(struct timespec *tv)
 	 * made, and then undo it!
 	 */
 	nsec -= do_gettimeoffset() * NSEC_PER_USEC;
-	nsec -= (jiffies - wall_jiffies) * TICK_NSEC;
 
 	wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
 	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);

arch/m68k/kernel/time.c

@@ -96,31 +96,23 @@ void time_init(void)
 void do_gettimeofday(struct timeval *tv)
 {
 	unsigned long flags;
-	extern unsigned long wall_jiffies;
 	unsigned long seq;
-	unsigned long usec, sec, lost;
+	unsigned long usec, sec;
 	unsigned long max_ntp_tick = tick_usec - tickadj;
 
 	do {
 		seq = read_seqbegin_irqsave(&xtime_lock, flags);
 
 		usec = mach_gettimeoffset();
-		lost = jiffies - wall_jiffies;
 
 		/*
 		 * If time_adjust is negative then NTP is slowing the clock
 		 * so make sure not to go into next possible interval.
 		 * Better to lose some accuracy than have time go backwards..
 		 */
-		if (unlikely(time_adjust < 0)) {
+		if (unlikely(time_adjust < 0))
 			usec = min(usec, max_ntp_tick);
 
-			if (lost)
-				usec += lost * max_ntp_tick;
-		}
-		else if (unlikely(lost))
-			usec += lost * tick_usec;
-
 		sec = xtime.tv_sec;
 		usec += xtime.tv_nsec/1000;
 	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
@@ -141,7 +133,6 @@ int do_settimeofday(struct timespec *tv)
 {
 	time_t wtm_sec, sec = tv->tv_sec;
 	long wtm_nsec, nsec = tv->tv_nsec;
-	extern unsigned long wall_jiffies;
 
 	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 		return -EINVAL;
@@ -153,8 +144,7 @@ int do_settimeofday(struct timespec *tv)
 	 * Discover what correction gettimeofday
 	 * would have done, and then undo it!
 	 */
-	nsec -= 1000 * (mach_gettimeoffset() +
-			(jiffies - wall_jiffies) * (1000000 / HZ));
+	nsec -= 1000 * mach_gettimeoffset();
 
 	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
 	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);

arch/m68knommu/kernel/time.c

@@ -26,8 +26,6 @@
 
 #define	TICK_SIZE (tick_nsec / 1000)
 
-extern unsigned long wall_jiffies;
-
 
 static inline int set_rtc_mmss(unsigned long nowtime)
 {
@@ -124,15 +122,12 @@ void time_init(void)
 void do_gettimeofday(struct timeval *tv)
 {
 	unsigned long flags;
-	unsigned long lost, seq;
+	unsigned long seq;
 	unsigned long usec, sec;
 
 	do {
 		seq = read_seqbegin_irqsave(&xtime_lock, flags);
 		usec = mach_gettimeoffset ? mach_gettimeoffset() : 0;
-		lost = jiffies - wall_jiffies;
-		if (lost)
-			usec += lost * (1000000 / HZ);
 		sec = xtime.tv_sec;
 		usec += (xtime.tv_nsec / 1000);
 	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));

arch/mips/kernel/time.c

@@ -47,8 +47,6 @@
 /*
  * forward reference
  */
-extern volatile unsigned long wall_jiffies;
-
 DEFINE_SPINLOCK(rtc_lock);
 
 /*
@@ -159,7 +157,6 @@ void (*mips_hpt_init)(unsigned int);
 void do_gettimeofday(struct timeval *tv)
 {
 	unsigned long seq;
-	unsigned long lost;
 	unsigned long usec, sec;
 	unsigned long max_ntp_tick;
 
@@ -168,8 +165,6 @@ void do_gettimeofday(struct timeval *tv)
 
 		usec = do_gettimeoffset();
 
-		lost = jiffies - wall_jiffies;
-
 		/*
 		 * If time_adjust is negative then NTP is slowing the clock
 		 * so make sure not to go into next possible interval.
@@ -178,11 +173,7 @@ void do_gettimeofday(struct timeval *tv)
 		if (unlikely(time_adjust < 0)) {
 			max_ntp_tick = (USEC_PER_SEC / HZ) - tickadj;
 			usec = min(usec, max_ntp_tick);
-
-			if (lost)
-				usec += lost * max_ntp_tick;
-		} else if (unlikely(lost))
-			usec += lost * (USEC_PER_SEC / HZ);
+		}
 
 		sec = xtime.tv_sec;
 		usec += (xtime.tv_nsec / 1000);
@@ -217,7 +208,6 @@ int do_settimeofday(struct timespec *tv)
 	 * made, and then undo it!
 	 */
 	nsec -= do_gettimeoffset() * NSEC_PER_USEC;
-	nsec -= (jiffies - wall_jiffies) * tick_nsec;
 
 	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
 	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);

arch/mips/sgi-ip27/ip27-timer.c

@@ -42,8 +42,6 @@
 static unsigned long ct_cur[NR_CPUS];	/* What counter should be at next timer irq */
 static long last_rtc_update;		/* Last time the rtc clock got updated */
 
-extern volatile unsigned long wall_jiffies;
-
 #if 0
 static int set_rtc_mmss(unsigned long nowtime)
 {

arch/parisc/kernel/time.c

@@ -32,9 +32,6 @@
 
 #include <linux/timex.h>
 
-/* xtime and wall_jiffies keep wall-clock time */
-extern unsigned long wall_jiffies;
-
 static long clocktick __read_mostly;	/* timer cycles per tick */
 static long halftick __read_mostly;
 
@@ -112,7 +109,7 @@ EXPORT_SYMBOL(profile_pc);
 /*** converted from ia64 ***/
 /*
  * Return the number of micro-seconds that elapsed since the last
- * update to wall time (aka xtime aka wall_jiffies).  The xtime_lock
+ * update to wall time (aka xtime).  The xtime_lock
  * must be at least read-locked when calling this routine.
  */
 static inline unsigned long