提交 3171a030 编写于 作者: A Atsushi Nemoto 提交者: Linus Torvalds

[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
5aee405c 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: NAtsushi 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: NRussell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Hirokazu Takata <takata.hirokazu@renesas.com>
Acked-by: NRalf 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: N"Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
上级 27d91e07
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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);
/*
......
......@@ -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 */
......
......@@ -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
......
......@@ -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);
......
......@@ -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
......
......@@ -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
......
......@@ -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));
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -111,7 +111,7 @@ void ip27_rt_timer_interrupt(struct pt_regs *regs)
kstat_this_cpu.irqs[irq]++; /* kstat only for bootcpu? */
if (cpu == 0)
do_timer(regs);
do_timer(1);
update_process_times(user_mode(regs));
......
......@@ -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);
}
}
......
......@@ -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();
}
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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();
......
......@@ -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;
......
......@@ -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
......
......@@ -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
......
......@@ -175,7 +175,7 @@ irqreturn_t timer_interrupt (int irq, void *dev_id, struct pt_regs *regs)
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 &&
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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));
......
......@@ -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();
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
......
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