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Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

Browse source 
* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (26 commits)
  posix timers: fix RLIMIT_CPU && fork()
  time: ntp: fix bug in ntp_update_offset() & do_adjtimex(), fix
  time: ntp: clean up second_overflow()
  time: ntp: simplify ntp_tick_adj calculations
  time: ntp: make 64-bit constants more robust
  time: ntp: refactor do_adjtimex() some more
  time: ntp: refactor do_adjtimex()
  time: ntp: fix bug in ntp_update_offset() & do_adjtimex()
  time: ntp: micro-optimize ntp_update_offset()
  time: ntp: simplify ntp_update_offset_fll()
  time: ntp: refactor and clean up ntp_update_offset()
  time: ntp: refactor up ntp_update_frequency()
  time: ntp: clean up ntp_update_frequency()
  time: ntp: simplify the MAX_TICKADJ_SCALED definition
  time: ntp: simplify the second_overflow() code flow
  time: ntp: clean up kernel/time/ntp.c
  x86: hpet: stop HPET_COUNTER when programming periodic mode
  x86: hpet: provide separate functions to stop and start the counter
  x86: hpet: print HPET registers during setup (if hpet=verbose is used)
  time: apply NTP frequency/tick changes immediately
  ...
This commit is contained in:
Linus Torvalds 2009-03-26 16:05:42 -07:00
commit 6671de344c
12 changed files with 444 additions and 268 deletions
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4
Documentation/kernel-parameters.txt
View file

@ -493,10 +493,12 @@ and is between 256 and 4096 characters. It is defined in the file
Default: 64
hpet= [X86-32,HPET] option to control HPET usage
Format: { enable (default) | disable | force }
Format: { enable (default) | disable | force |
verbose }
disable: disable HPET and use PIT instead
force: allow force enabled of undocumented chips (ICH4,
VIA, nVidia)
verbose: show contents of HPET registers during setup
com20020= [HW,NET] ARCnet - COM20020 chipset
Format:

2
arch/powerpc/platforms/cell/spufs/sched.c
View file

@ -508,7 +508,7 @@ static void __spu_add_to_rq(struct spu_context *ctx)
list_add_tail(&ctx->rq, &spu_prio->runq[ctx->prio]);
set_bit(ctx->prio, spu_prio->bitmap);
if (!spu_prio->nr_waiting++)
__mod_timer(&spusched_timer, jiffies + SPUSCHED_TICK);
mod_timer(&spusched_timer, jiffies + SPUSCHED_TICK);
}
}

80
arch/x86/kernel/hpet.c
View file

@ -80,6 +80,7 @@ static inline void hpet_clear_mapping(void)
*/
static int boot_hpet_disable;
int hpet_force_user;
static int hpet_verbose;
static int __init hpet_setup(char *str)
{
@ -88,6 +89,8 @@ static int __init hpet_setup(char *str)
boot_hpet_disable = 1;
if (!strncmp("force", str, 5))
hpet_force_user = 1;
if (!strncmp("verbose", str, 7))
hpet_verbose = 1;
}
return 1;
}
@ -119,6 +122,43 @@ int is_hpet_enabled(void)
}
EXPORT_SYMBOL_GPL(is_hpet_enabled);
static void _hpet_print_config(const char *function, int line)
{
u32 i, timers, l, h;
printk(KERN_INFO "hpet: %s(%d):\n", function, line);
l = hpet_readl(HPET_ID);
h = hpet_readl(HPET_PERIOD);
timers = ((l & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;
printk(KERN_INFO "hpet: ID: 0x%x, PERIOD: 0x%x\n", l, h);
l = hpet_readl(HPET_CFG);
h = hpet_readl(HPET_STATUS);
printk(KERN_INFO "hpet: CFG: 0x%x, STATUS: 0x%x\n", l, h);
l = hpet_readl(HPET_COUNTER);
h = hpet_readl(HPET_COUNTER+4);
printk(KERN_INFO "hpet: COUNTER_l: 0x%x, COUNTER_h: 0x%x\n", l, h);
for (i = 0; i < timers; i++) {
l = hpet_readl(HPET_Tn_CFG(i));
h = hpet_readl(HPET_Tn_CFG(i)+4);
printk(KERN_INFO "hpet: T%d: CFG_l: 0x%x, CFG_h: 0x%x\n",
i, l, h);
l = hpet_readl(HPET_Tn_CMP(i));
h = hpet_readl(HPET_Tn_CMP(i)+4);
printk(KERN_INFO "hpet: T%d: CMP_l: 0x%x, CMP_h: 0x%x\n",
i, l, h);
l = hpet_readl(HPET_Tn_ROUTE(i));
h = hpet_readl(HPET_Tn_ROUTE(i)+4);
printk(KERN_INFO "hpet: T%d ROUTE_l: 0x%x, ROUTE_h: 0x%x\n",
i, l, h);
}
}
#define hpet_print_config() \
do { \
if (hpet_verbose) \
_hpet_print_config(__FUNCTION__, __LINE__); \
} while (0)
/*
* When the hpet driver (/dev/hpet) is enabled, we need to reserve
* timer 0 and timer 1 in case of RTC emulation.
@ -191,27 +231,37 @@ static struct clock_event_device hpet_clockevent = {
.rating = 50,
};
static void hpet_start_counter(void)
static void hpet_stop_counter(void)
{
unsigned long cfg = hpet_readl(HPET_CFG);
cfg &= ~HPET_CFG_ENABLE;
hpet_writel(cfg, HPET_CFG);
hpet_writel(0, HPET_COUNTER);
hpet_writel(0, HPET_COUNTER + 4);
}
static void hpet_start_counter(void)
{
unsigned long cfg = hpet_readl(HPET_CFG);
cfg |= HPET_CFG_ENABLE;
hpet_writel(cfg, HPET_CFG);
}
static void hpet_restart_counter(void)
{
hpet_stop_counter();
hpet_start_counter();
}
static void hpet_resume_device(void)
{
force_hpet_resume();
}
static void hpet_restart_counter(void)
static void hpet_resume_counter(void)
{
hpet_resume_device();
hpet_start_counter();
hpet_restart_counter();
}
static void hpet_enable_legacy_int(void)
@ -259,29 +309,23 @@ static int hpet_setup_msi_irq(unsigned int irq);
static void hpet_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt, int timer)
{
unsigned long cfg, cmp, now;
unsigned long cfg;
uint64_t delta;
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
hpet_stop_counter();
delta = ((uint64_t)(NSEC_PER_SEC/HZ)) * evt->mult;
delta >>= evt->shift;
now = hpet_readl(HPET_COUNTER);
cmp = now + (unsigned long) delta;
cfg = hpet_readl(HPET_Tn_CFG(timer));
/* Make sure we use edge triggered interrupts */
cfg &= ~HPET_TN_LEVEL;
cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC |
HPET_TN_SETVAL | HPET_TN_32BIT;
hpet_writel(cfg, HPET_Tn_CFG(timer));
/*
* The first write after writing TN_SETVAL to the
* config register sets the counter value, the second
* write sets the period.
*/
hpet_writel(cmp, HPET_Tn_CMP(timer));
udelay(1);
hpet_writel((unsigned long) delta, HPET_Tn_CMP(timer));
hpet_start_counter();
hpet_print_config();
break;
case CLOCK_EVT_MODE_ONESHOT:
@ -308,6 +352,7 @@ static void hpet_set_mode(enum clock_event_mode mode,
irq_set_affinity(hdev->irq, cpumask_of(hdev->cpu));
enable_irq(hdev->irq);
}
hpet_print_config();
break;
}
}
@ -526,6 +571,7 @@ static void hpet_msi_capability_lookup(unsigned int start_timer)
num_timers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT);
num_timers++; /* Value read out starts from 0 */
hpet_print_config();
hpet_devs = kzalloc(sizeof(struct hpet_dev) * num_timers, GFP_KERNEL);
if (!hpet_devs)
@ -695,7 +741,7 @@ static struct clocksource clocksource_hpet = {
.mask = HPET_MASK,
.shift = HPET_SHIFT,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
.resume = hpet_restart_counter,
.resume = hpet_resume_counter,
#ifdef CONFIG_X86_64
.vread = vread_hpet,
#endif
@ -707,7 +753,7 @@ static int hpet_clocksource_register(void)
cycle_t t1;
/* Start the counter */
hpet_start_counter();
hpet_restart_counter();
/* Verify whether hpet counter works */
t1 = read_hpet();
@ -793,6 +839,7 @@ int __init hpet_enable(void)
* information and the number of channels
*/
id = hpet_readl(HPET_ID);
hpet_print_config();
#ifdef CONFIG_HPET_EMULATE_RTC
/*
@ -845,6 +892,7 @@ static __init int hpet_late_init(void)
return -ENODEV;
hpet_reserve_platform_timers(hpet_readl(HPET_ID));
hpet_print_config();
for_each_online_cpu(cpu) {
hpet_cpuhp_notify(NULL, CPU_ONLINE, (void *)(long)cpu);

3
arch/x86/kernel/quirks.c
View file

@ -172,7 +172,8 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH8_4,
ich_force_enable_hpet);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH9_7,
ich_force_enable_hpet);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x3a16, /* ICH10 */
ich_force_enable_hpet);
static struct pci_dev *cached_dev;

6
drivers/infiniband/hw/ipath/ipath_driver.c
View file

@ -2715,7 +2715,7 @@ static void ipath_hol_signal_up(struct ipath_devdata *dd)
* to prevent HoL blocking, then start the HoL timer that
* periodically continues, then stop procs, so they can detect
* link down if they want, and do something about it.
* Timer may already be running, so use __mod_timer, not add_timer.
* Timer may already be running, so use mod_timer, not add_timer.
*/
void ipath_hol_down(struct ipath_devdata *dd)
{
@ -2724,7 +2724,7 @@ void ipath_hol_down(struct ipath_devdata *dd)
dd->ipath_hol_next = IPATH_HOL_DOWNCONT;
dd->ipath_hol_timer.expires = jiffies +
msecs_to_jiffies(ipath_hol_timeout_ms);
__mod_timer(&dd->ipath_hol_timer, dd->ipath_hol_timer.expires);
mod_timer(&dd->ipath_hol_timer, dd->ipath_hol_timer.expires);
}
/*
@ -2763,7 +2763,7 @@ void ipath_hol_event(unsigned long opaque)
else {
dd->ipath_hol_timer.expires = jiffies +
msecs_to_jiffies(ipath_hol_timeout_ms);
__mod_timer(&dd->ipath_hol_timer,
mod_timer(&dd->ipath_hol_timer,
dd->ipath_hol_timer.expires);
}
}

22
include/linux/timer.h
View file

@ -86,8 +86,8 @@ static inline int timer_pending(const struct timer_list * timer)
extern void add_timer_on(struct timer_list *timer, int cpu);
extern int del_timer(struct timer_list * timer);
extern int __mod_timer(struct timer_list *timer, unsigned long expires);
extern int mod_timer(struct timer_list *timer, unsigned long expires);
extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
/*
* The jiffies value which is added to now, when there is no timer
@ -146,25 +146,7 @@ static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
}
#endif
/**
* add_timer - start a timer
* @timer: the timer to be added
*
* The kernel will do a ->function(->data) callback from the
* timer interrupt at the ->expires point in the future. The
* current time is 'jiffies'.
*
* The timer's ->expires, ->function (and if the handler uses it, ->data)
* fields must be set prior calling this function.
*
* Timers with an ->expires field in the past will be executed in the next
* timer tick.
*/
static inline void add_timer(struct timer_list *timer)
{
BUG_ON(timer_pending(timer));
__mod_timer(timer, timer->expires);
}
extern void add_timer(struct timer_list *timer);
#ifdef CONFIG_SMP
extern int try_to_del_timer_sync(struct timer_list *timer);

2
include/linux/timex.h
View file

@ -190,7 +190,7 @@ struct timex {
* offset and maximum frequency tolerance.
*/
#define SHIFT_USEC 16 /* frequency offset scale (shift) */
#define PPM_SCALE (NSEC_PER_USEC << (NTP_SCALE_SHIFT - SHIFT_USEC))
#define PPM_SCALE ((s64)NSEC_PER_USEC << (NTP_SCALE_SHIFT - SHIFT_USEC))
#define PPM_SCALE_INV_SHIFT 19
#define PPM_SCALE_INV ((1ll << (PPM_SCALE_INV_SHIFT + NTP_SCALE_SHIFT)) / \
PPM_SCALE + 1)

3
kernel/posix-cpu-timers.c
View file

@ -1370,7 +1370,8 @@ static inline int fastpath_timer_check(struct task_struct *tsk)
if (task_cputime_expired(&group_sample, &sig->cputime_expires))
return 1;
}
return 0;
return sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY;
}
/*

2
kernel/relay.c
View file

@ -750,7 +750,7 @@ size_t relay_switch_subbuf(struct rchan_buf *buf, size_t length)
* from the scheduler (trying to re-grab
* rq->lock), so defer it.
*/
__mod_timer(&buf->timer, jiffies + 1);
mod_timer(&buf->timer, jiffies + 1);
}
old = buf->data;

20
kernel/time/clockevents.c
View file

@ -68,6 +68,17 @@ void clockevents_set_mode(struct clock_event_device *dev,
if (dev->mode != mode) {
dev->set_mode(mode, dev);
dev->mode = mode;
/*
* A nsec2cyc multiplicator of 0 is invalid and we'd crash
* on it, so fix it up and emit a warning:
*/
if (mode == CLOCK_EVT_MODE_ONESHOT) {
if (unlikely(!dev->mult)) {
dev->mult = 1;
WARN_ON(1);
}
}
}
}
@ -168,15 +179,6 @@ void clockevents_register_device(struct clock_event_device *dev)
BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
BUG_ON(!dev->cpumask);
/*
* A nsec2cyc multiplicator of 0 is invalid and we'd crash
* on it, so fix it up and emit a warning:
*/
if (unlikely(!dev->mult)) {
dev->mult = 1;
WARN_ON(1);
}
spin_lock(&clockevents_lock);
list_add(&dev->list, &clockevent_devices);

442
kernel/time/ntp.c
View file

@ -1,71 +1,129 @@
/*
* linux/kernel/time/ntp.c
*
* NTP state machine interfaces and logic.
*
* This code was mainly moved from kernel/timer.c and kernel/time.c
* Please see those files for relevant copyright info and historical
* changelogs.
*/
#include <linux/mm.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/jiffies.h>
#include <linux/hrtimer.h>
#include <linux/capability.h>
#include <linux/math64.h>
#include <linux/clocksource.h>
#include <linux/workqueue.h>
#include <asm/timex.h>
#include <linux/hrtimer.h>
#include <linux/jiffies.h>
#include <linux/math64.h>
#include <linux/timex.h>
#include <linux/time.h>
#include <linux/mm.h>
/*
* Timekeeping variables
* NTP timekeeping variables:
*/
unsigned long tick_usec = TICK_USEC; /* USER_HZ period (usec) */
unsigned long tick_nsec; /* ACTHZ period (nsec) */
u64 tick_length;
static u64 tick_length_base;
static struct hrtimer leap_timer;
/* USER_HZ period (usecs): */
unsigned long tick_usec = TICK_USEC;
#define MAX_TICKADJ 500 /* microsecs */
#define MAX_TICKADJ_SCALED (((u64)(MAX_TICKADJ * NSEC_PER_USEC) << \
NTP_SCALE_SHIFT) / NTP_INTERVAL_FREQ)
/* ACTHZ period (nsecs): */
unsigned long tick_nsec;
u64 tick_length;
static u64 tick_length_base;
static struct hrtimer leap_timer;
#define MAX_TICKADJ 500LL /* usecs */
#define MAX_TICKADJ_SCALED \
(((MAX_TICKADJ * NSEC_PER_USEC) << NTP_SCALE_SHIFT) / NTP_INTERVAL_FREQ)
/*
* phase-lock loop variables
*/
/* TIME_ERROR prevents overwriting the CMOS clock */
static int time_state = TIME_OK; /* clock synchronization status */
int time_status = STA_UNSYNC; /* clock status bits */
static long time_tai; /* TAI offset (s) */
static s64 time_offset; /* time adjustment (ns) */
static long time_constant = 2; /* pll time constant */
long time_maxerror = NTP_PHASE_LIMIT; /* maximum error (us) */
long time_esterror = NTP_PHASE_LIMIT; /* estimated error (us) */
static s64 time_freq; /* frequency offset (scaled ns/s)*/
static long time_reftime; /* time at last adjustment (s) */
long time_adjust;
static long ntp_tick_adj;
/*
* clock synchronization status
*
* (TIME_ERROR prevents overwriting the CMOS clock)
*/
static int time_state = TIME_OK;
/* clock status bits: */
int time_status = STA_UNSYNC;
/* TAI offset (secs): */
static long time_tai;
/* time adjustment (nsecs): */
static s64 time_offset;
/* pll time constant: */
static long time_constant = 2;
/* maximum error (usecs): */
long time_maxerror = NTP_PHASE_LIMIT;
/* estimated error (usecs): */
long time_esterror = NTP_PHASE_LIMIT;
/* frequency offset (scaled nsecs/secs): */
static s64 time_freq;
/* time at last adjustment (secs): */
static long time_reftime;
long time_adjust;
/* constant (boot-param configurable) NTP tick adjustment (upscaled) */
static s64 ntp_tick_adj;
/*
* NTP methods:
*/
/*
* Update (tick_length, tick_length_base, tick_nsec), based
* on (tick_usec, ntp_tick_adj, time_freq):
*/
static void ntp_update_frequency(void)
{
u64 second_length = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)
<< NTP_SCALE_SHIFT;
second_length += (s64)ntp_tick_adj << NTP_SCALE_SHIFT;
second_length += time_freq;
u64 second_length;
u64 new_base;
tick_length_base = second_length;
second_length = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)
<< NTP_SCALE_SHIFT;
tick_nsec = div_u64(second_length, HZ) >> NTP_SCALE_SHIFT;
tick_length_base = div_u64(tick_length_base, NTP_INTERVAL_FREQ);
second_length += ntp_tick_adj;
second_length += time_freq;
tick_nsec = div_u64(second_length, HZ) >> NTP_SCALE_SHIFT;
new_base = div_u64(second_length, NTP_INTERVAL_FREQ);
/*
* Don't wait for the next second_overflow, apply
* the change to the tick length immediately:
*/
tick_length += new_base - tick_length_base;
tick_length_base = new_base;
}
static inline s64 ntp_update_offset_fll(s64 offset64, long secs)
{
time_status &= ~STA_MODE;
if (secs < MINSEC)
return 0;
if (!(time_status & STA_FLL) && (secs <= MAXSEC))
return 0;
time_status |= STA_MODE;
return div_s64(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs);
}
static void ntp_update_offset(long offset)
{
long mtemp;
s64 freq_adj;
s64 offset64;
long secs;
if (!(time_status & STA_PLL))
return;
@ -84,24 +142,23 @@ static void ntp_update_offset(long offset)
* Select how the frequency is to be controlled
* and in which mode (PLL or FLL).
*/
if (time_status & STA_FREQHOLD || time_reftime == 0)
time_reftime = xtime.tv_sec;
mtemp = xtime.tv_sec - time_reftime;
secs = xtime.tv_sec - time_reftime;
if (unlikely(time_status & STA_FREQHOLD))
secs = 0;
time_reftime = xtime.tv_sec;
freq_adj = (s64)offset * mtemp;
freq_adj <<= NTP_SCALE_SHIFT - 2 * (SHIFT_PLL + 2 + time_constant);
time_status &= ~STA_MODE;
if (mtemp >= MINSEC && (time_status & STA_FLL || mtemp > MAXSEC)) {
freq_adj += div_s64((s64)offset << (NTP_SCALE_SHIFT - SHIFT_FLL),
mtemp);
time_status |= STA_MODE;
}
freq_adj += time_freq;
freq_adj = min(freq_adj, MAXFREQ_SCALED);
time_freq = max(freq_adj, -MAXFREQ_SCALED);
offset64 = offset;
freq_adj = (offset64 * secs) <<
(NTP_SCALE_SHIFT - 2 * (SHIFT_PLL + 2 + time_constant));
time_offset = div_s64((s64)offset << NTP_SCALE_SHIFT, NTP_INTERVAL_FREQ);
freq_adj += ntp_update_offset_fll(offset64, secs);
freq_adj = min(freq_adj + time_freq, MAXFREQ_SCALED);
time_freq = max(freq_adj, -MAXFREQ_SCALED);
time_offset = div_s64(offset64 << NTP_SCALE_SHIFT, NTP_INTERVAL_FREQ);
}
/**
@ -111,15 +168,15 @@ static void ntp_update_offset(long offset)
*/
void ntp_clear(void)
{
time_adjust = 0; /* stop active adjtime() */
time_status |= STA_UNSYNC;
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
time_adjust = 0; /* stop active adjtime() */
time_status |= STA_UNSYNC;
time_maxerror = NTP_PHASE_LIMIT;
time_esterror = NTP_PHASE_LIMIT;
ntp_update_frequency();
tick_length = tick_length_base;
time_offset = 0;
tick_length = tick_length_base;
time_offset = 0;
}
/*
@ -140,8 +197,8 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
xtime.tv_sec--;
wall_to_monotonic.tv_sec++;
time_state = TIME_OOP;
printk(KERN_NOTICE "Clock: "
"inserting leap second 23:59:60 UTC\n");
printk(KERN_NOTICE
"Clock: inserting leap second 23:59:60 UTC\n");
hrtimer_add_expires_ns(&leap_timer, NSEC_PER_SEC);
res = HRTIMER_RESTART;
break;
@ -150,8 +207,8 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
time_tai--;
wall_to_monotonic.tv_sec--;
time_state = TIME_WAIT;
printk(KERN_NOTICE "Clock: "
"deleting leap second 23:59:59 UTC\n");
printk(KERN_NOTICE
"Clock: deleting leap second 23:59:59 UTC\n");
break;
case TIME_OOP:
time_tai++;
@ -179,7 +236,7 @@ static enum hrtimer_restart ntp_leap_second(struct hrtimer *timer)
*/
void second_overflow(void)
{
s64 time_adj;
s64 delta;
/* Bump the maxerror field */
time_maxerror += MAXFREQ / NSEC_PER_USEC;
@ -192,24 +249,30 @@ void second_overflow(void)
* Compute the phase adjustment for the next second. The offset is
* reduced by a fixed factor times the time constant.
*/
tick_length = tick_length_base;
time_adj = shift_right(time_offset, SHIFT_PLL + time_constant);
time_offset -= time_adj;
tick_length += time_adj;
tick_length = tick_length_base;
if (unlikely(time_adjust)) {
if (time_adjust > MAX_TICKADJ) {
time_adjust -= MAX_TICKADJ;
tick_length += MAX_TICKADJ_SCALED;
} else if (time_adjust < -MAX_TICKADJ) {
time_adjust += MAX_TICKADJ;
tick_length -= MAX_TICKADJ_SCALED;
} else {
tick_length += (s64)(time_adjust * NSEC_PER_USEC /
NTP_INTERVAL_FREQ) << NTP_SCALE_SHIFT;
time_adjust = 0;
}
delta = shift_right(time_offset, SHIFT_PLL + time_constant);
time_offset -= delta;
tick_length += delta;
if (!time_adjust)
return;
if (time_adjust > MAX_TICKADJ) {
time_adjust -= MAX_TICKADJ;
tick_length += MAX_TICKADJ_SCALED;
return;
}
if (time_adjust < -MAX_TICKADJ) {
time_adjust += MAX_TICKADJ;
tick_length -= MAX_TICKADJ_SCALED;
return;
}
tick_length += (s64)(time_adjust * NSEC_PER_USEC / NTP_INTERVAL_FREQ)
<< NTP_SCALE_SHIFT;
time_adjust = 0;
}
#ifdef CONFIG_GENERIC_CMOS_UPDATE
@ -233,12 +296,13 @@ static void sync_cmos_clock(struct work_struct *work)
* This code is run on a timer. If the clock is set, that timer
* may not expire at the correct time. Thus, we adjust...
*/
if (!ntp_synced())
if (!ntp_synced()) {
/*
* Not synced, exit, do not restart a timer (if one is
* running, let it run out).
*/
return;
}
getnstimeofday(&now);
if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec / 2)
@ -270,7 +334,116 @@ static void notify_cmos_timer(void)
static inline void notify_cmos_timer(void) { }
#endif
/* adjtimex mainly allows reading (and writing, if superuser) of
/*
* Start the leap seconds timer:
*/
static inline void ntp_start_leap_timer(struct timespec *ts)
{
long now = ts->tv_sec;
if (time_status & STA_INS) {
time_state = TIME_INS;
now += 86400 - now % 86400;
hrtimer_start(&leap_timer, ktime_set(now, 0), HRTIMER_MODE_ABS);
return;
}
if (time_status & STA_DEL) {
time_state = TIME_DEL;
now += 86400 - (now + 1) % 86400;
hrtimer_start(&leap_timer, ktime_set(now, 0), HRTIMER_MODE_ABS);
}
}
/*
* Propagate a new txc->status value into the NTP state:
*/
static inline void process_adj_status(struct timex *txc, struct timespec *ts)
{
if ((time_status & STA_PLL) && !(txc->status & STA_PLL)) {
time_state = TIME_OK;
time_status = STA_UNSYNC;
}
/*
* If we turn on PLL adjustments then reset the
* reference time to current time.
*/
if (!(time_status & STA_PLL) && (txc->status & STA_PLL))
time_reftime = xtime.tv_sec;
/* only set allowed bits */
time_status &= STA_RONLY;
time_status |= txc->status & ~STA_RONLY;
switch (time_state) {
case TIME_OK:
ntp_start_leap_timer(ts);
break;
case TIME_INS:
case TIME_DEL:
time_state = TIME_OK;
ntp_start_leap_timer(ts);
case TIME_WAIT:
if (!(time_status & (STA_INS | STA_DEL)))
time_state = TIME_OK;
break;
case TIME_OOP:
hrtimer_restart(&leap_timer);
break;
}
}
/*
* Called with the xtime lock held, so we can access and modify
* all the global NTP state:
*/
static inline void process_adjtimex_modes(struct timex *txc, struct timespec *ts)
{
if (txc->modes & ADJ_STATUS)
process_adj_status(txc, ts);
if (txc->modes & ADJ_NANO)
time_status |= STA_NANO;
if (txc->modes & ADJ_MICRO)
time_status &= ~STA_NANO;
if (txc->modes & ADJ_FREQUENCY) {
time_freq = txc->freq * PPM_SCALE;
time_freq = min(time_freq, MAXFREQ_SCALED);
time_freq = max(time_freq, -MAXFREQ_SCALED);
}
if (txc->modes & ADJ_MAXERROR)
time_maxerror = txc->maxerror;
if (txc->modes & ADJ_ESTERROR)
time_esterror = txc->esterror;
if (txc->modes & ADJ_TIMECONST) {
time_constant = txc->constant;
if (!(time_status & STA_NANO))
time_constant += 4;
time_constant = min(time_constant, (long)MAXTC);
time_constant = max(time_constant, 0l);
}
if (txc->modes & ADJ_TAI && txc->constant > 0)
time_tai = txc->constant;
if (txc->modes & ADJ_OFFSET)
ntp_update_offset(txc->offset);
if (txc->modes & ADJ_TICK)
tick_usec = txc->tick;
if (txc->modes & (ADJ_TICK|ADJ_FREQUENCY|ADJ_OFFSET))
ntp_update_frequency();
}
/*
* adjtimex mainly allows reading (and writing, if superuser) of
* kernel time-keeping variables. used by xntpd.
*/
int do_adjtimex(struct timex *txc)
@ -291,11 +464,14 @@ int do_adjtimex(struct timex *txc)
if (txc->modes && !capable(CAP_SYS_TIME))
return -EPERM;
/* if the quartz is off by more than 10% something is VERY wrong! */
/*
* if the quartz is off by more than 10% then
* something is VERY wrong!
*/
if (txc->modes & ADJ_TICK &&
(txc->tick < 900000/USER_HZ ||
txc->tick > 1100000/USER_HZ))
return -EINVAL;
return -EINVAL;
if (txc->modes & ADJ_STATUS && time_state != TIME_OK)
hrtimer_cancel(&leap_timer);
@ -305,7 +481,6 @@ int do_adjtimex(struct timex *txc)
write_seqlock_irq(&xtime_lock);
/* If there are input parameters, then process them */
if (txc->modes & ADJ_ADJTIME) {
long save_adjust = time_adjust;
@ -315,98 +490,24 @@ int do_adjtimex(struct timex *txc)
ntp_update_frequency();
}
txc->offset = save_adjust;
goto adj_done;
}
if (txc->modes) {
long sec;
} else {
if (txc->modes & ADJ_STATUS) {
if ((time_status & STA_PLL) &&
!(txc->status & STA_PLL)) {
time_state = TIME_OK;
time_status = STA_UNSYNC;
}
/* only set allowed bits */
time_status &= STA_RONLY;
time_status |= txc->status & ~STA_RONLY;
/* If there are input parameters, then process them: */
if (txc->modes)
process_adjtimex_modes(txc, &ts);
switch (time_state) {
case TIME_OK:
start_timer:
sec = ts.tv_sec;
if (time_status & STA_INS) {
time_state = TIME_INS;
sec += 86400 - sec % 86400;
hrtimer_start(&leap_timer, ktime_set(sec, 0), HRTIMER_MODE_ABS);
} else if (time_status & STA_DEL) {
time_state = TIME_DEL;
sec += 86400 - (sec + 1) % 86400;
hrtimer_start(&leap_timer, ktime_set(sec, 0), HRTIMER_MODE_ABS);
}
break;
case TIME_INS:
case TIME_DEL:
time_state = TIME_OK;
goto start_timer;
break;
case TIME_WAIT:
if (!(time_status & (STA_INS | STA_DEL)))
time_state = TIME_OK;
break;
case TIME_OOP:
hrtimer_restart(&leap_timer);
break;
}
}
if (txc->modes & ADJ_NANO)
time_status |= STA_NANO;
if (txc->modes & ADJ_MICRO)
time_status &= ~STA_NANO;
if (txc->modes & ADJ_FREQUENCY) {
time_freq = (s64)txc->freq * PPM_SCALE;
time_freq = min(time_freq, MAXFREQ_SCALED);
time_freq = max(time_freq, -MAXFREQ_SCALED);
}
if (txc->modes & ADJ_MAXERROR)
time_maxerror = txc->maxerror;
if (txc->modes & ADJ_ESTERROR)
time_esterror = txc->esterror;
if (txc->modes & ADJ_TIMECONST) {
time_constant = txc->constant;
if (!(time_status & STA_NANO))
time_constant += 4;
time_constant = min(time_constant, (long)MAXTC);
time_constant = max(time_constant, 0l);
}
if (txc->modes & ADJ_TAI && txc->constant > 0)
time_tai = txc->constant;
if (txc->modes & ADJ_OFFSET)
ntp_update_offset(txc->offset);
if (txc->modes & ADJ_TICK)
tick_usec = txc->tick;
if (txc->modes & (ADJ_TICK|ADJ_FREQUENCY|ADJ_OFFSET))
ntp_update_frequency();
}
txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ,
txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ,
NTP_SCALE_SHIFT);
if (!(time_status & STA_NANO))
txc->offset /= NSEC_PER_USEC;
if (!(time_status & STA_NANO))
txc->offset /= NSEC_PER_USEC;
}
adj_done:
result = time_state; /* mostly `TIME_OK' */
if (time_status & (STA_UNSYNC|STA_CLOCKERR))
result = TIME_ERROR;
txc->freq = shift_right((time_freq >> PPM_SCALE_INV_SHIFT) *
(s64)PPM_SCALE_INV, NTP_SCALE_SHIFT);
PPM_SCALE_INV, NTP_SCALE_SHIFT);
txc->maxerror = time_maxerror;
txc->esterror = time_esterror;
txc->status = time_status;
@ -425,6 +526,7 @@ adj_done:
txc->calcnt = 0;
txc->errcnt = 0;
txc->stbcnt = 0;
write_sequnlock_irq(&xtime_lock);
txc->time.tv_sec = ts.tv_sec;
@ -440,6 +542,8 @@ adj_done:
static int __init ntp_tick_adj_setup(char *str)
{
ntp_tick_adj = simple_strtol(str, NULL, 0);
ntp_tick_adj <<= NTP_SCALE_SHIFT;
return 1;
}

126
kernel/timer.c
View file

@ -589,11 +589,14 @@ static struct tvec_base *lock_timer_base(struct timer_list *timer,
}
}
int __mod_timer(struct timer_list *timer, unsigned long expires)
static inline int
__mod_timer(struct timer_list *timer, unsigned long expires, bool pending_only)
{
struct tvec_base *base, *new_base;
unsigned long flags;
int ret = 0;
int ret;
ret = 0;
timer_stats_timer_set_start_info(timer);
BUG_ON(!timer->function);
@ -603,6 +606,9 @@ int __mod_timer(struct timer_list *timer, unsigned long expires)
if (timer_pending(timer)) {
detach_timer(timer, 0);
ret = 1;
} else {
if (pending_only)
goto out_unlock;
}
debug_timer_activate(timer);
@ -629,12 +635,83 @@ int __mod_timer(struct timer_list *timer, unsigned long expires)
timer->expires = expires;
internal_add_timer(base, timer);
out_unlock:
spin_unlock_irqrestore(&base->lock, flags);
return ret;
}
EXPORT_SYMBOL(__mod_timer);
/**
* mod_timer_pending - modify a pending timer's timeout
* @timer: the pending timer to be modified
* @expires: new timeout in jiffies
*
* mod_timer_pending() is the same for pending timers as mod_timer(),
* but will not re-activate and modify already deleted timers.
*
* It is useful for unserialized use of timers.
*/
int mod_timer_pending(struct timer_list *timer, unsigned long expires)
{
return __mod_timer(timer, expires, true);
}
EXPORT_SYMBOL(mod_timer_pending);
/**
* mod_timer - modify a timer's timeout
* @timer: the timer to be modified
* @expires: new timeout in jiffies
*
* mod_timer() is a more efficient way to update the expire field of an
* active timer (if the timer is inactive it will be activated)
*
* mod_timer(timer, expires) is equivalent to:
*
* del_timer(timer); timer->expires = expires; add_timer(timer);
*
* Note that if there are multiple unserialized concurrent users of the
* same timer, then mod_timer() is the only safe way to modify the timeout,
* since add_timer() cannot modify an already running timer.
*
* The function returns whether it has modified a pending timer or not.
* (ie. mod_timer() of an inactive timer returns 0, mod_timer() of an
* active timer returns 1.)
*/
int mod_timer(struct timer_list *timer, unsigned long expires)
{
/*
* This is a common optimization triggered by the
* networking code - if the timer is re-modified
* to be the same thing then just return:
*/
if (timer->expires == expires && timer_pending(timer))
return 1;
return __mod_timer(timer, expires, false);
}
EXPORT_SYMBOL(mod_timer);
/**
* add_timer - start a timer
* @timer: the timer to be added
*
* The kernel will do a ->function(->data) callback from the
* timer interrupt at the ->expires point in the future. The
* current time is 'jiffies'.
*
* The timer's ->expires, ->function (and if the handler uses it, ->data)
* fields must be set prior calling this function.
*
* Timers with an ->expires field in the past will be executed in the next
* timer tick.
*/
void add_timer(struct timer_list *timer)
{
BUG_ON(timer_pending(timer));
mod_timer(timer, timer->expires);
}
EXPORT_SYMBOL(add_timer);
/**
* add_timer_on - start a timer on a particular CPU
@ -666,44 +743,6 @@ void add_timer_on(struct timer_list *timer, int cpu)
spin_unlock_irqrestore(&base->lock, flags);
}
/**
* mod_timer - modify a timer's timeout
* @timer: the timer to be modified
* @expires: new timeout in jiffies
*
* mod_timer() is a more efficient way to update the expire field of an
* active timer (if the timer is inactive it will be activated)
*
* mod_timer(timer, expires) is equivalent to:
*
* del_timer(timer); timer->expires = expires; add_timer(timer);
*
* Note that if there are multiple unserialized concurrent users of the
* same timer, then mod_timer() is the only safe way to modify the timeout,
* since add_timer() cannot modify an already running timer.
*
* The function returns whether it has modified a pending timer or not.
* (ie. mod_timer() of an inactive timer returns 0, mod_timer() of an
* active timer returns 1.)
*/
int mod_timer(struct timer_list *timer, unsigned long expires)
{
BUG_ON(!timer->function);
timer_stats_timer_set_start_info(timer);
/*
* This is a common optimization triggered by the
* networking code - if the timer is re-modified
* to be the same thing then just return:
*/
if (timer->expires == expires && timer_pending(timer))
return 1;
return __mod_timer(timer, expires);
}
EXPORT_SYMBOL(mod_timer);
/**
* del_timer - deactive a timer.
* @timer: the timer to be deactivated
@ -733,7 +772,6 @@ int del_timer(struct timer_list *timer)
return ret;
}
EXPORT_SYMBOL(del_timer);
#ifdef CONFIG_SMP
@ -767,7 +805,6 @@ out:
return ret;
}
EXPORT_SYMBOL(try_to_del_timer_sync);
/**
@ -796,7 +833,6 @@ int del_timer_sync(struct timer_list *timer)
cpu_relax();
}
}
EXPORT_SYMBOL(del_timer_sync);
#endif
@ -1268,7 +1304,7 @@ signed long __sched schedule_timeout(signed long timeout)
expire = timeout + jiffies;
setup_timer_on_stack(&timer, process_timeout, (unsigned long)current);
__mod_timer(&timer, expire);
__mod_timer(&timer, expire, false);
schedule();
del_singleshot_timer_sync(&timer);