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[PATCH] simplify update_times (avoid jiffies/jiffies_64 aliasing problem) 

Pass ticks to do_timer() and update_times(), and adjust x86_64 and s390
timer interrupt handler with this change.

Currently update_times() calculates ticks by "jiffies - wall_jiffies", but
callers of do_timer() should know how many ticks to update.  Passing ticks
get rid of this redundant calculation.  Also there are another redundancy
pointed out by Martin Schwidefsky.

This cleanup make a barrier added by
5aee405c66 needless.  So this patch removes
it.

As a bonus, this cleanup make wall_jiffies can be removed easily, since now
wall_jiffies is always synced with jiffies.  (This patch does not really
remove wall_jiffies.  It would be another cleanup patch)

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
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>
Acked-by: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Hirokazu Takata <takata.hirokazu@renesas.com>
Acked-by: 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>
Acked-by: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Atsushi Nemoto 2006-09-29 02:00:32 -07:00 committed by Linus Torvalds
parent 27d91e07f9
commit 3171a0305d
38 changed files with 52 additions and 60 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/alpha/kernel/time.c
View File

@ -132,7 +132,7 @@ irqreturn_t timer_interrupt(int irq, void *dev, struct pt_regs * regs)
nticks = delta >> FIX_SHIFT;
while (nticks > 0) {
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif

2
arch/arm/kernel/time.c
View File

@ -337,7 +337,7 @@ void timer_tick(struct pt_regs *regs)
profile_tick(CPU_PROFILING, regs);
do_leds();
do_set_rtc();
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif

2
arch/arm26/kernel/time.c
View File

@ -194,7 +194,7 @@ EXPORT_SYMBOL(do_settimeofday);
static irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif

2
arch/avr32/kernel/time.c
View File

@ -148,7 +148,7 @@ timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
* Call the generic timer interrupt handler
*/
write_seqlock(&xtime_lock);
do_timer(regs);
do_timer(1);
write_sequnlock(&xtime_lock);
/*

2
arch/cris/arch-v10/kernel/time.c
View File

@ -227,7 +227,7 @@ timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
/* call the real timer interrupt handler */
do_timer(regs);
do_timer(1);
cris_do_profile(regs); /* Save profiling information */

2
arch/cris/arch-v32/kernel/time.c
View File

@ -219,7 +219,7 @@ timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
return IRQ_HANDLED;
/* call the real timer interrupt handler */
do_timer(regs);
do_timer(1);
/*
* If we have an externally synchronized Linux clock, then update

2
arch/frv/kernel/time.c
View File

@ -70,7 +70,7 @@ static irqreturn_t timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
*/
write_seqlock(&xtime_lock);
do_timer(regs);
do_timer(1);
update_process_times(user_mode(regs));
profile_tick(CPU_PROFILING, regs);

2
arch/h8300/kernel/time.c
View File

@ -41,7 +41,7 @@ static void timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
/* may need to kick the hardware timer */
platform_timer_eoi();
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif

2
arch/ia64/kernel/time.c
View File

@ -78,7 +78,7 @@ timer_interrupt (int irq, void *dev_id, struct pt_regs *regs)
* xtime_lock.
*/
write_seqlock(&xtime_lock);
do_timer(regs);
do_timer(1);
local_cpu_data->itm_next = new_itm;
write_sequnlock(&xtime_lock);
} else

2
arch/m32r/kernel/time.c
View File

@ -202,7 +202,7 @@ irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
#ifndef CONFIG_SMP
profile_tick(CPU_PROFILING, regs);
#endif
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));

2
arch/m68k/kernel/time.c
View File

@ -40,7 +40,7 @@ static inline int set_rtc_mmss(unsigned long nowtime)
*/
static irqreturn_t timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
{
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif

2
arch/m68k/sun3/sun3ints.c
View File

@ -65,7 +65,7 @@ static irqreturn_t sun3_int5(int irq, void *dev_id, struct pt_regs *fp)
#ifdef CONFIG_SUN3
intersil_clear();
#endif
do_timer(fp);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(fp));
#endif

2
arch/m68knommu/kernel/time.c
View File

@ -51,7 +51,7 @@ static irqreturn_t timer_interrupt(int irq, void *dummy, struct pt_regs * regs)
write_seqlock(&xtime_lock);
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif

6
arch/mips/au1000/common/time.c
View File

@ -96,7 +96,7 @@ void mips_timer_interrupt(struct pt_regs *regs)
timerlo = count;
kstat_this_cpu.irqs[irq]++;
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif
@ -137,7 +137,7 @@ irqreturn_t counter0_irq(int irq, void *dev_id, struct pt_regs *regs)
}
while (time_elapsed > 0) {
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif
@ -156,7 +156,7 @@ irqreturn_t counter0_irq(int irq, void *dev_id, struct pt_regs *regs)
if (jiffie_drift >= 999) {
jiffie_drift -= 999;
do_timer(regs); /* increment jiffies by one */
do_timer(1); /* increment jiffies by one */
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif

2
arch/mips/gt64120/common/time.c
View File

@ -34,7 +34,7 @@ static void gt64120_irq(int irq, void *dev_id, struct pt_regs *regs)
if (irq_src & 0x00000800) { /* Check for timer interrupt */
handled = 1;
irq_src &= ~0x00000800;
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif

2
arch/mips/kernel/time.c
View File

@ -434,7 +434,7 @@ irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
/*
* call the generic timer interrupt handling
*/
do_timer(regs);
do_timer(1);
/*
* If we have an externally synchronized Linux clock, then update

2
arch/mips/momentum/ocelot_g/gt-irq.c
View File

@ -133,7 +133,7 @@ static irqreturn_t gt64240_p0int_irq(int irq, void *dev, struct pt_regs *regs)
MV_WRITE(TIMER_COUNTER_0_3_INTERRUPT_CAUSE, 0x0);
/* handle the timer call */
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif

2
arch/mips/sgi-ip27/ip27-timer.c
View File

@ -111,7 +111,7 @@ again:
kstat_this_cpu.irqs[irq]++; /* kstat only for bootcpu? */
if (cpu == 0)
do_timer(regs);
do_timer(1);
update_process_times(user_mode(regs));

2
arch/parisc/kernel/time.c
View File

@ -79,7 +79,7 @@ irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
#endif
if (cpu == 0) {
write_seqlock(&xtime_lock);
do_timer(regs);
do_timer(1);
write_sequnlock(&xtime_lock);
}
}

2
arch/powerpc/kernel/time.c
View File

@ -693,7 +693,7 @@ void timer_interrupt(struct pt_regs * regs)
tb_next_jiffy = tb_last_jiffy + tb_ticks_per_jiffy;
if (per_cpu(last_jiffy, cpu) >= tb_next_jiffy) {
tb_last_jiffy = tb_next_jiffy;
do_timer(regs);
do_timer(1);
timer_recalc_offset(tb_last_jiffy);
timer_check_rtc();
}

2
arch/ppc/kernel/time.c
View File

@ -153,7 +153,7 @@ void timer_interrupt(struct pt_regs * regs)
/* We are in an interrupt, no need to save/restore flags */
write_seqlock(&xtime_lock);
tb_last_stamp = jiffy_stamp;
do_timer(regs);
do_timer(1);
/*
* update the rtc when needed, this should be performed on the

9
arch/s390/kernel/time.c
View File

@ -166,7 +166,7 @@ EXPORT_SYMBOL(do_settimeofday);
void account_ticks(struct pt_regs *regs)
{
__u64 tmp;
__u32 ticks, xticks;
__u32 ticks;
/* Calculate how many ticks have passed. */
if (S390_lowcore.int_clock < S390_lowcore.jiffy_timer) {
@ -204,6 +204,7 @@ void account_ticks(struct pt_regs *regs)
*/
write_seqlock(&xtime_lock);
if (S390_lowcore.jiffy_timer > xtime_cc) {
__u32 xticks;
tmp = S390_lowcore.jiffy_timer - xtime_cc;
if (tmp >= 2*CLK_TICKS_PER_JIFFY) {
xticks = __div(tmp, CLK_TICKS_PER_JIFFY);
@ -212,13 +213,11 @@ void account_ticks(struct pt_regs *regs)
xticks = 1;
xtime_cc += CLK_TICKS_PER_JIFFY;
}
while (xticks--)
do_timer(regs);
do_timer(xticks);
}
write_sequnlock(&xtime_lock);
#else
for (xticks = ticks; xticks > 0; xticks--)
do_timer(regs);
do_timer(ticks);
#endif
#ifdef CONFIG_VIRT_CPU_ACCOUNTING

2
arch/sh/kernel/time.c
View File

@ -117,7 +117,7 @@ static long last_rtc_update;
*/
void handle_timer_tick(struct pt_regs *regs)
{
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif

2
arch/sh64/kernel/time.c
View File

@ -298,7 +298,7 @@ static inline void do_timer_interrupt(int irq, struct pt_regs *regs)
asm ("getcon cr62, %0" : "=r" (current_ctc));
ctc_last_interrupt = (unsigned long) current_ctc;
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif

2
arch/sparc/kernel/pcic.c
View File

@ -712,7 +712,7 @@ static irqreturn_t pcic_timer_handler (int irq, void *h, struct pt_regs *regs)
{
write_seqlock(&xtime_lock); /* Dummy, to show that we remember */
pcic_clear_clock_irq();
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif

2
arch/sparc/kernel/time.c
View File

@ -128,7 +128,7 @@ irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs * regs)
#endif
clear_clock_irq();
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif

4
arch/sparc64/kernel/time.c
View File

@ -465,7 +465,7 @@ irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs * regs)
profile_tick(CPU_PROFILING, regs);
update_process_times(user_mode(regs));
#endif
do_timer(regs);
do_timer(1);
/* Guarantee that the following sequences execute
* uninterrupted.
@ -496,7 +496,7 @@ void timer_tick_interrupt(struct pt_regs *regs)
{
write_seqlock(&xtime_lock);
do_timer(regs);
do_timer(1);
timer_check_rtc();

2
arch/um/kernel/time.c
View File

@ -93,7 +93,7 @@ irqreturn_t um_timer(int irq, void *dev, struct pt_regs *regs)
write_seqlock_irqsave(&xtime_lock, flags);
do_timer(regs);
do_timer(1);
nsecs = get_time();
xtime.tv_sec = nsecs / NSEC_PER_SEC;

2
arch/v850/kernel/time.c
View File

@ -51,7 +51,7 @@ static irqreturn_t timer_interrupt (int irq, void *dummy, struct pt_regs *regs)
if (mach_tick)
mach_tick ();
do_timer (regs);
do_timer (1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif

8
arch/x86_64/kernel/time.c
View File

@ -415,16 +415,16 @@ void main_timer_handler(struct pt_regs *regs)
(((long) offset << US_SCALE) / vxtime.tsc_quot) - 1;
}
if (lost > 0) {
if (lost > 0)
handle_lost_ticks(lost, regs);
jiffies += lost;
}
else
lost = 0;
/*
* Do the timer stuff.
*/
do_timer(regs);
do_timer(lost + 1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif

2
arch/xtensa/kernel/time.c
View File

@ -175,7 +175,7 @@ again:
last_ccount_stamp = next;
next += CCOUNT_PER_JIFFY;
do_timer (regs); /* Linux handler in kernel/timer.c */
do_timer (1); /* Linux handler in kernel/timer.c */
if (ntp_synced() &&
xtime.tv_sec - last_rtc_update >= 659 &&

2
include/asm-arm/arch-clps711x/time.h
View File

@ -29,7 +29,7 @@ static irqreturn_t
p720t_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
do_leds();
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif

2
include/asm-arm/arch-l7200/time.h
View File

@ -45,7 +45,7 @@
static irqreturn_t
timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif

2
include/asm-i386/mach-default/do_timer.h
View File

@ -16,7 +16,7 @@
static inline void do_timer_interrupt_hook(struct pt_regs *regs)
{
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode_vm(regs));
#endif

2
include/asm-i386/mach-visws/do_timer.h
View File

@ -9,7 +9,7 @@ static inline void do_timer_interrupt_hook(struct pt_regs *regs)
/* Clear the interrupt */
co_cpu_write(CO_CPU_STAT,co_cpu_read(CO_CPU_STAT) & ~CO_STAT_TIMEINTR);
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode_vm(regs));
#endif

2
include/asm-i386/mach-voyager/do_timer.h
View File

@ -3,7 +3,7 @@
static inline void do_timer_interrupt_hook(struct pt_regs *regs)
{
do_timer(regs);
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode_vm(regs));
#endif

2
include/linux/sched.h
View File

@ -1206,7 +1206,7 @@ extern void switch_uid(struct user_struct *);
#include <asm/current.h>
extern void do_timer(struct pt_regs *);
extern void do_timer(unsigned long ticks);
extern int FASTCALL(wake_up_state(struct task_struct * tsk, unsigned int state));
extern int FASTCALL(wake_up_process(struct task_struct * tsk));

19
kernel/timer.c
View File

@ -1222,10 +1222,8 @@ 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();
active_tasks = count_active_tasks();
for (count -= ticks; count < 0; count += LOAD_FREQ) {
CALC_LOAD(avenrun[0], EXP_1, active_tasks);
CALC_LOAD(avenrun[1], EXP_5, active_tasks);
CALC_LOAD(avenrun[2], EXP_15, active_tasks);
@ -1270,11 +1268,8 @@ void run_local_timers(void)
* Called by the timer interrupt. xtime_lock must already be taken
* by the timer IRQ!
*/
static inline void update_times(void)
static inline void update_times(unsigned long ticks)
{
unsigned long ticks;
ticks = jiffies - wall_jiffies;
wall_jiffies += ticks;
update_wall_time();
calc_load(ticks);
@ -1286,12 +1281,10 @@ static inline void update_times(void)
* jiffies is defined in the linker script...
*/
void do_timer(struct pt_regs *regs)
void do_timer(unsigned long ticks)
{
jiffies_64++;
/* prevent loading jiffies before storing new jiffies_64 value. */
barrier();
update_times();
jiffies_64 += ticks;
update_times(ticks);
}
#ifdef __ARCH_WANT_SYS_ALARM