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-rw-r--r--kernel/time/clockevents.c45
-rw-r--r--kernel/time/clocksource.c105
-rw-r--r--kernel/time/tick-broadcast.c42
-rw-r--r--kernel/time/tick-common.c20
-rw-r--r--kernel/time/tick-internal.h1
-rw-r--r--kernel/time/tick-oneshot.c4
-rw-r--r--kernel/time/tick-sched.c141
-rw-r--r--kernel/time/timecompare.c8
-rw-r--r--kernel/time/timekeeping.c102
-rw-r--r--kernel/time/timer_list.c25
-rw-r--r--kernel/time/timer_stats.c18
11 files changed, 354 insertions, 157 deletions
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 620b58abdc32..6f740d9f0948 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -20,6 +20,8 @@
20#include <linux/sysdev.h> 20#include <linux/sysdev.h>
21#include <linux/tick.h> 21#include <linux/tick.h>
22 22
23#include "tick-internal.h"
24
23/* The registered clock event devices */ 25/* The registered clock event devices */
24static LIST_HEAD(clockevent_devices); 26static LIST_HEAD(clockevent_devices);
25static LIST_HEAD(clockevents_released); 27static LIST_HEAD(clockevents_released);
@@ -28,7 +30,7 @@ static LIST_HEAD(clockevents_released);
28static RAW_NOTIFIER_HEAD(clockevents_chain); 30static RAW_NOTIFIER_HEAD(clockevents_chain);
29 31
30/* Protection for the above */ 32/* Protection for the above */
31static DEFINE_SPINLOCK(clockevents_lock); 33static DEFINE_RAW_SPINLOCK(clockevents_lock);
32 34
33/** 35/**
34 * clockevents_delta2ns - Convert a latch value (device ticks) to nanoseconds 36 * clockevents_delta2ns - Convert a latch value (device ticks) to nanoseconds
@@ -37,10 +39,9 @@ static DEFINE_SPINLOCK(clockevents_lock);
37 * 39 *
38 * Math helper, returns latch value converted to nanoseconds (bound checked) 40 * Math helper, returns latch value converted to nanoseconds (bound checked)
39 */ 41 */
40unsigned long clockevent_delta2ns(unsigned long latch, 42u64 clockevent_delta2ns(unsigned long latch, struct clock_event_device *evt)
41 struct clock_event_device *evt)
42{ 43{
43 u64 clc = ((u64) latch << evt->shift); 44 u64 clc = (u64) latch << evt->shift;
44 45
45 if (unlikely(!evt->mult)) { 46 if (unlikely(!evt->mult)) {
46 evt->mult = 1; 47 evt->mult = 1;
@@ -50,10 +51,10 @@ unsigned long clockevent_delta2ns(unsigned long latch,
50 do_div(clc, evt->mult); 51 do_div(clc, evt->mult);
51 if (clc < 1000) 52 if (clc < 1000)
52 clc = 1000; 53 clc = 1000;
53 if (clc > LONG_MAX) 54 if (clc > KTIME_MAX)
54 clc = LONG_MAX; 55 clc = KTIME_MAX;
55 56
56 return (unsigned long) clc; 57 return clc;
57} 58}
58EXPORT_SYMBOL_GPL(clockevent_delta2ns); 59EXPORT_SYMBOL_GPL(clockevent_delta2ns);
59 60
@@ -140,9 +141,9 @@ int clockevents_register_notifier(struct notifier_block *nb)
140 unsigned long flags; 141 unsigned long flags;
141 int ret; 142 int ret;
142 143
143 spin_lock_irqsave(&clockevents_lock, flags); 144 raw_spin_lock_irqsave(&clockevents_lock, flags);
144 ret = raw_notifier_chain_register(&clockevents_chain, nb); 145 ret = raw_notifier_chain_register(&clockevents_chain, nb);
145 spin_unlock_irqrestore(&clockevents_lock, flags); 146 raw_spin_unlock_irqrestore(&clockevents_lock, flags);
146 147
147 return ret; 148 return ret;
148} 149}
@@ -184,13 +185,13 @@ void clockevents_register_device(struct clock_event_device *dev)
184 BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED); 185 BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
185 BUG_ON(!dev->cpumask); 186 BUG_ON(!dev->cpumask);
186 187
187 spin_lock_irqsave(&clockevents_lock, flags); 188 raw_spin_lock_irqsave(&clockevents_lock, flags);
188 189
189 list_add(&dev->list, &clockevent_devices); 190 list_add(&dev->list, &clockevent_devices);
190 clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev); 191 clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev);
191 clockevents_notify_released(); 192 clockevents_notify_released();
192 193
193 spin_unlock_irqrestore(&clockevents_lock, flags); 194 raw_spin_unlock_irqrestore(&clockevents_lock, flags);
194} 195}
195EXPORT_SYMBOL_GPL(clockevents_register_device); 196EXPORT_SYMBOL_GPL(clockevents_register_device);
196 197
@@ -237,10 +238,11 @@ void clockevents_exchange_device(struct clock_event_device *old,
237 */ 238 */
238void clockevents_notify(unsigned long reason, void *arg) 239void clockevents_notify(unsigned long reason, void *arg)
239{ 240{
240 struct list_head *node, *tmp; 241 struct clock_event_device *dev, *tmp;
241 unsigned long flags; 242 unsigned long flags;
243 int cpu;
242 244
243 spin_lock_irqsave(&clockevents_lock, flags); 245 raw_spin_lock_irqsave(&clockevents_lock, flags);
244 clockevents_do_notify(reason, arg); 246 clockevents_do_notify(reason, arg);
245 247
246 switch (reason) { 248 switch (reason) {
@@ -249,13 +251,24 @@ void clockevents_notify(unsigned long reason, void *arg)
249 * Unregister the clock event devices which were 251 * Unregister the clock event devices which were
250 * released from the users in the notify chain. 252 * released from the users in the notify chain.
251 */ 253 */
252 list_for_each_safe(node, tmp, &clockevents_released) 254 list_for_each_entry_safe(dev, tmp, &clockevents_released, list)
253 list_del(node); 255 list_del(&dev->list);
256 /*
257 * Now check whether the CPU has left unused per cpu devices
258 */
259 cpu = *((int *)arg);
260 list_for_each_entry_safe(dev, tmp, &clockevent_devices, list) {
261 if (cpumask_test_cpu(cpu, dev->cpumask) &&
262 cpumask_weight(dev->cpumask) == 1) {
263 BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
264 list_del(&dev->list);
265 }
266 }
254 break; 267 break;
255 default: 268 default:
256 break; 269 break;
257 } 270 }
258 spin_unlock_irqrestore(&clockevents_lock, flags); 271 raw_spin_unlock_irqrestore(&clockevents_lock, flags);
259} 272}
260EXPORT_SYMBOL_GPL(clockevents_notify); 273EXPORT_SYMBOL_GPL(clockevents_notify);
261#endif 274#endif
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 5e18c6ab2c6a..e85c23404d34 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -39,7 +39,7 @@ void timecounter_init(struct timecounter *tc,
39 tc->cycle_last = cc->read(cc); 39 tc->cycle_last = cc->read(cc);
40 tc->nsec = start_tstamp; 40 tc->nsec = start_tstamp;
41} 41}
42EXPORT_SYMBOL(timecounter_init); 42EXPORT_SYMBOL_GPL(timecounter_init);
43 43
44/** 44/**
45 * timecounter_read_delta - get nanoseconds since last call of this function 45 * timecounter_read_delta - get nanoseconds since last call of this function
@@ -83,7 +83,7 @@ u64 timecounter_read(struct timecounter *tc)
83 83
84 return nsec; 84 return nsec;
85} 85}
86EXPORT_SYMBOL(timecounter_read); 86EXPORT_SYMBOL_GPL(timecounter_read);
87 87
88u64 timecounter_cyc2time(struct timecounter *tc, 88u64 timecounter_cyc2time(struct timecounter *tc,
89 cycle_t cycle_tstamp) 89 cycle_t cycle_tstamp)
@@ -105,7 +105,60 @@ u64 timecounter_cyc2time(struct timecounter *tc,
105 105
106 return nsec; 106 return nsec;
107} 107}
108EXPORT_SYMBOL(timecounter_cyc2time); 108EXPORT_SYMBOL_GPL(timecounter_cyc2time);
109
110/**
111 * clocks_calc_mult_shift - calculate mult/shift factors for scaled math of clocks
112 * @mult: pointer to mult variable
113 * @shift: pointer to shift variable
114 * @from: frequency to convert from
115 * @to: frequency to convert to
116 * @minsec: guaranteed runtime conversion range in seconds
117 *
118 * The function evaluates the shift/mult pair for the scaled math
119 * operations of clocksources and clockevents.
120 *
121 * @to and @from are frequency values in HZ. For clock sources @to is
122 * NSEC_PER_SEC == 1GHz and @from is the counter frequency. For clock
123 * event @to is the counter frequency and @from is NSEC_PER_SEC.
124 *
125 * The @minsec conversion range argument controls the time frame in
126 * seconds which must be covered by the runtime conversion with the
127 * calculated mult and shift factors. This guarantees that no 64bit
128 * overflow happens when the input value of the conversion is
129 * multiplied with the calculated mult factor. Larger ranges may
130 * reduce the conversion accuracy by chosing smaller mult and shift
131 * factors.
132 */
133void
134clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 minsec)
135{
136 u64 tmp;
137 u32 sft, sftacc= 32;
138
139 /*
140 * Calculate the shift factor which is limiting the conversion
141 * range:
142 */
143 tmp = ((u64)minsec * from) >> 32;
144 while (tmp) {
145 tmp >>=1;
146 sftacc--;
147 }
148
149 /*
150 * Find the conversion shift/mult pair which has the best
151 * accuracy and fits the maxsec conversion range:
152 */
153 for (sft = 32; sft > 0; sft--) {
154 tmp = (u64) to << sft;
155 do_div(tmp, from);
156 if ((tmp >> sftacc) == 0)
157 break;
158 }
159 *mult = tmp;
160 *shift = sft;
161}
109 162
110/*[Clocksource internal variables]--------- 163/*[Clocksource internal variables]---------
111 * curr_clocksource: 164 * curr_clocksource:
@@ -413,6 +466,47 @@ void clocksource_touch_watchdog(void)
413 clocksource_resume_watchdog(); 466 clocksource_resume_watchdog();
414} 467}
415 468
469/**
470 * clocksource_max_deferment - Returns max time the clocksource can be deferred
471 * @cs: Pointer to clocksource
472 *
473 */
474static u64 clocksource_max_deferment(struct clocksource *cs)
475{
476 u64 max_nsecs, max_cycles;
477
478 /*
479 * Calculate the maximum number of cycles that we can pass to the
480 * cyc2ns function without overflowing a 64-bit signed result. The
481 * maximum number of cycles is equal to ULLONG_MAX/cs->mult which
482 * is equivalent to the below.
483 * max_cycles < (2^63)/cs->mult
484 * max_cycles < 2^(log2((2^63)/cs->mult))
485 * max_cycles < 2^(log2(2^63) - log2(cs->mult))
486 * max_cycles < 2^(63 - log2(cs->mult))
487 * max_cycles < 1 << (63 - log2(cs->mult))
488 * Please note that we add 1 to the result of the log2 to account for
489 * any rounding errors, ensure the above inequality is satisfied and
490 * no overflow will occur.
491 */
492 max_cycles = 1ULL << (63 - (ilog2(cs->mult) + 1));
493
494 /*
495 * The actual maximum number of cycles we can defer the clocksource is
496 * determined by the minimum of max_cycles and cs->mask.
497 */
498 max_cycles = min_t(u64, max_cycles, (u64) cs->mask);
499 max_nsecs = clocksource_cyc2ns(max_cycles, cs->mult, cs->shift);
500
501 /*
502 * To ensure that the clocksource does not wrap whilst we are idle,
503 * limit the time the clocksource can be deferred by 12.5%. Please
504 * note a margin of 12.5% is used because this can be computed with
505 * a shift, versus say 10% which would require division.
506 */
507 return max_nsecs - (max_nsecs >> 5);
508}
509
416#ifdef CONFIG_GENERIC_TIME 510#ifdef CONFIG_GENERIC_TIME
417 511
418/** 512/**
@@ -511,6 +605,9 @@ static void clocksource_enqueue(struct clocksource *cs)
511 */ 605 */
512int clocksource_register(struct clocksource *cs) 606int clocksource_register(struct clocksource *cs)
513{ 607{
608 /* calculate max idle time permitted for this clocksource */
609 cs->max_idle_ns = clocksource_max_deferment(cs);
610
514 mutex_lock(&clocksource_mutex); 611 mutex_lock(&clocksource_mutex);
515 clocksource_enqueue(cs); 612 clocksource_enqueue(cs);
516 clocksource_select(); 613 clocksource_select();
@@ -580,7 +677,7 @@ sysfs_show_current_clocksources(struct sys_device *dev,
580 * @count: length of buffer 677 * @count: length of buffer
581 * 678 *
582 * Takes input from sysfs interface for manually overriding the default 679 * Takes input from sysfs interface for manually overriding the default
583 * clocksource selction. 680 * clocksource selection.
584 */ 681 */
585static ssize_t sysfs_override_clocksource(struct sys_device *dev, 682static ssize_t sysfs_override_clocksource(struct sys_device *dev,
586 struct sysdev_attribute *attr, 683 struct sysdev_attribute *attr,
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index c2ec25087a35..b3bafd5fc66d 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -31,7 +31,7 @@ static struct tick_device tick_broadcast_device;
31/* FIXME: Use cpumask_var_t. */ 31/* FIXME: Use cpumask_var_t. */
32static DECLARE_BITMAP(tick_broadcast_mask, NR_CPUS); 32static DECLARE_BITMAP(tick_broadcast_mask, NR_CPUS);
33static DECLARE_BITMAP(tmpmask, NR_CPUS); 33static DECLARE_BITMAP(tmpmask, NR_CPUS);
34static DEFINE_SPINLOCK(tick_broadcast_lock); 34static DEFINE_RAW_SPINLOCK(tick_broadcast_lock);
35static int tick_broadcast_force; 35static int tick_broadcast_force;
36 36
37#ifdef CONFIG_TICK_ONESHOT 37#ifdef CONFIG_TICK_ONESHOT
@@ -96,7 +96,7 @@ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu)
96 unsigned long flags; 96 unsigned long flags;
97 int ret = 0; 97 int ret = 0;
98 98
99 spin_lock_irqsave(&tick_broadcast_lock, flags); 99 raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
100 100
101 /* 101 /*
102 * Devices might be registered with both periodic and oneshot 102 * Devices might be registered with both periodic and oneshot
@@ -122,7 +122,7 @@ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu)
122 tick_broadcast_clear_oneshot(cpu); 122 tick_broadcast_clear_oneshot(cpu);
123 } 123 }
124 } 124 }
125 spin_unlock_irqrestore(&tick_broadcast_lock, flags); 125 raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
126 return ret; 126 return ret;
127} 127}
128 128
@@ -161,13 +161,13 @@ static void tick_do_broadcast(struct cpumask *mask)
161 */ 161 */
162static void tick_do_periodic_broadcast(void) 162static void tick_do_periodic_broadcast(void)
163{ 163{
164 spin_lock(&tick_broadcast_lock); 164 raw_spin_lock(&tick_broadcast_lock);
165 165
166 cpumask_and(to_cpumask(tmpmask), 166 cpumask_and(to_cpumask(tmpmask),
167 cpu_online_mask, tick_get_broadcast_mask()); 167 cpu_online_mask, tick_get_broadcast_mask());
168 tick_do_broadcast(to_cpumask(tmpmask)); 168 tick_do_broadcast(to_cpumask(tmpmask));
169 169
170 spin_unlock(&tick_broadcast_lock); 170 raw_spin_unlock(&tick_broadcast_lock);
171} 171}
172 172
173/* 173/*
@@ -212,7 +212,7 @@ static void tick_do_broadcast_on_off(unsigned long *reason)
212 unsigned long flags; 212 unsigned long flags;
213 int cpu, bc_stopped; 213 int cpu, bc_stopped;
214 214
215 spin_lock_irqsave(&tick_broadcast_lock, flags); 215 raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
216 216
217 cpu = smp_processor_id(); 217 cpu = smp_processor_id();
218 td = &per_cpu(tick_cpu_device, cpu); 218 td = &per_cpu(tick_cpu_device, cpu);
@@ -263,7 +263,7 @@ static void tick_do_broadcast_on_off(unsigned long *reason)
263 tick_broadcast_setup_oneshot(bc); 263 tick_broadcast_setup_oneshot(bc);
264 } 264 }
265out: 265out:
266 spin_unlock_irqrestore(&tick_broadcast_lock, flags); 266 raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
267} 267}
268 268
269/* 269/*
@@ -299,7 +299,7 @@ void tick_shutdown_broadcast(unsigned int *cpup)
299 unsigned long flags; 299 unsigned long flags;
300 unsigned int cpu = *cpup; 300 unsigned int cpu = *cpup;
301 301
302 spin_lock_irqsave(&tick_broadcast_lock, flags); 302 raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
303 303
304 bc = tick_broadcast_device.evtdev; 304 bc = tick_broadcast_device.evtdev;
305 cpumask_clear_cpu(cpu, tick_get_broadcast_mask()); 305 cpumask_clear_cpu(cpu, tick_get_broadcast_mask());
@@ -309,7 +309,7 @@ void tick_shutdown_broadcast(unsigned int *cpup)
309 clockevents_shutdown(bc); 309 clockevents_shutdown(bc);
310 } 310 }
311 311
312 spin_unlock_irqrestore(&tick_broadcast_lock, flags); 312 raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
313} 313}
314 314
315void tick_suspend_broadcast(void) 315void tick_suspend_broadcast(void)
@@ -317,13 +317,13 @@ void tick_suspend_broadcast(void)
317 struct clock_event_device *bc; 317 struct clock_event_device *bc;
318 unsigned long flags; 318 unsigned long flags;
319 319
320 spin_lock_irqsave(&tick_broadcast_lock, flags); 320 raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
321 321
322 bc = tick_broadcast_device.evtdev; 322 bc = tick_broadcast_device.evtdev;
323 if (bc) 323 if (bc)
324 clockevents_shutdown(bc); 324 clockevents_shutdown(bc);
325 325
326 spin_unlock_irqrestore(&tick_broadcast_lock, flags); 326 raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
327} 327}
328 328
329int tick_resume_broadcast(void) 329int tick_resume_broadcast(void)
@@ -332,7 +332,7 @@ int tick_resume_broadcast(void)
332 unsigned long flags; 332 unsigned long flags;
333 int broadcast = 0; 333 int broadcast = 0;
334 334
335 spin_lock_irqsave(&tick_broadcast_lock, flags); 335 raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
336 336
337 bc = tick_broadcast_device.evtdev; 337 bc = tick_broadcast_device.evtdev;
338 338
@@ -351,7 +351,7 @@ int tick_resume_broadcast(void)
351 break; 351 break;
352 } 352 }
353 } 353 }
354 spin_unlock_irqrestore(&tick_broadcast_lock, flags); 354 raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
355 355
356 return broadcast; 356 return broadcast;
357} 357}
@@ -405,7 +405,7 @@ static void tick_handle_oneshot_broadcast(struct clock_event_device *dev)
405 ktime_t now, next_event; 405 ktime_t now, next_event;
406 int cpu; 406 int cpu;
407 407
408 spin_lock(&tick_broadcast_lock); 408 raw_spin_lock(&tick_broadcast_lock);
409again: 409again:
410 dev->next_event.tv64 = KTIME_MAX; 410 dev->next_event.tv64 = KTIME_MAX;
411 next_event.tv64 = KTIME_MAX; 411 next_event.tv64 = KTIME_MAX;
@@ -443,7 +443,7 @@ again:
443 if (tick_broadcast_set_event(next_event, 0)) 443 if (tick_broadcast_set_event(next_event, 0))
444 goto again; 444 goto again;
445 } 445 }
446 spin_unlock(&tick_broadcast_lock); 446 raw_spin_unlock(&tick_broadcast_lock);
447} 447}
448 448
449/* 449/*
@@ -457,7 +457,7 @@ void tick_broadcast_oneshot_control(unsigned long reason)
457 unsigned long flags; 457 unsigned long flags;
458 int cpu; 458 int cpu;
459 459
460 spin_lock_irqsave(&tick_broadcast_lock, flags); 460 raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
461 461
462 /* 462 /*
463 * Periodic mode does not care about the enter/exit of power 463 * Periodic mode does not care about the enter/exit of power
@@ -492,7 +492,7 @@ void tick_broadcast_oneshot_control(unsigned long reason)
492 } 492 }
493 493
494out: 494out:
495 spin_unlock_irqrestore(&tick_broadcast_lock, flags); 495 raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
496} 496}
497 497
498/* 498/*
@@ -563,13 +563,13 @@ void tick_broadcast_switch_to_oneshot(void)
563 struct clock_event_device *bc; 563 struct clock_event_device *bc;
564 unsigned long flags; 564 unsigned long flags;
565 565
566 spin_lock_irqsave(&tick_broadcast_lock, flags); 566 raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
567 567
568 tick_broadcast_device.mode = TICKDEV_MODE_ONESHOT; 568 tick_broadcast_device.mode = TICKDEV_MODE_ONESHOT;
569 bc = tick_broadcast_device.evtdev; 569 bc = tick_broadcast_device.evtdev;
570 if (bc) 570 if (bc)
571 tick_broadcast_setup_oneshot(bc); 571 tick_broadcast_setup_oneshot(bc);
572 spin_unlock_irqrestore(&tick_broadcast_lock, flags); 572 raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
573} 573}
574 574
575 575
@@ -581,7 +581,7 @@ void tick_shutdown_broadcast_oneshot(unsigned int *cpup)
581 unsigned long flags; 581 unsigned long flags;
582 unsigned int cpu = *cpup; 582 unsigned int cpu = *cpup;
583 583
584 spin_lock_irqsave(&tick_broadcast_lock, flags); 584 raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
585 585
586 /* 586 /*
587 * Clear the broadcast mask flag for the dead cpu, but do not 587 * Clear the broadcast mask flag for the dead cpu, but do not
@@ -589,7 +589,7 @@ void tick_shutdown_broadcast_oneshot(unsigned int *cpup)
589 */ 589 */
590 cpumask_clear_cpu(cpu, tick_get_broadcast_oneshot_mask()); 590 cpumask_clear_cpu(cpu, tick_get_broadcast_oneshot_mask());
591 591
592 spin_unlock_irqrestore(&tick_broadcast_lock, flags); 592 raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
593} 593}
594 594
595/* 595/*
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 83c4417b6a3c..b6b898d2eeef 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -34,7 +34,7 @@ DEFINE_PER_CPU(struct tick_device, tick_cpu_device);
34ktime_t tick_next_period; 34ktime_t tick_next_period;
35ktime_t tick_period; 35ktime_t tick_period;
36int tick_do_timer_cpu __read_mostly = TICK_DO_TIMER_BOOT; 36int tick_do_timer_cpu __read_mostly = TICK_DO_TIMER_BOOT;
37DEFINE_SPINLOCK(tick_device_lock); 37static DEFINE_RAW_SPINLOCK(tick_device_lock);
38 38
39/* 39/*
40 * Debugging: see timer_list.c 40 * Debugging: see timer_list.c
@@ -209,7 +209,7 @@ static int tick_check_new_device(struct clock_event_device *newdev)
209 int cpu, ret = NOTIFY_OK; 209 int cpu, ret = NOTIFY_OK;
210 unsigned long flags; 210 unsigned long flags;
211 211
212 spin_lock_irqsave(&tick_device_lock, flags); 212 raw_spin_lock_irqsave(&tick_device_lock, flags);
213 213
214 cpu = smp_processor_id(); 214 cpu = smp_processor_id();
215 if (!cpumask_test_cpu(cpu, newdev->cpumask)) 215 if (!cpumask_test_cpu(cpu, newdev->cpumask))
@@ -268,7 +268,7 @@ static int tick_check_new_device(struct clock_event_device *newdev)
268 if (newdev->features & CLOCK_EVT_FEAT_ONESHOT) 268 if (newdev->features & CLOCK_EVT_FEAT_ONESHOT)
269 tick_oneshot_notify(); 269 tick_oneshot_notify();
270 270
271 spin_unlock_irqrestore(&tick_device_lock, flags); 271 raw_spin_unlock_irqrestore(&tick_device_lock, flags);
272 return NOTIFY_STOP; 272 return NOTIFY_STOP;
273 273
274out_bc: 274out_bc:
@@ -278,7 +278,7 @@ out_bc:
278 if (tick_check_broadcast_device(newdev)) 278 if (tick_check_broadcast_device(newdev))
279 ret = NOTIFY_STOP; 279 ret = NOTIFY_STOP;
280 280
281 spin_unlock_irqrestore(&tick_device_lock, flags); 281 raw_spin_unlock_irqrestore(&tick_device_lock, flags);
282 282
283 return ret; 283 return ret;
284} 284}
@@ -311,7 +311,7 @@ static void tick_shutdown(unsigned int *cpup)
311 struct clock_event_device *dev = td->evtdev; 311 struct clock_event_device *dev = td->evtdev;
312 unsigned long flags; 312 unsigned long flags;
313 313
314 spin_lock_irqsave(&tick_device_lock, flags); 314 raw_spin_lock_irqsave(&tick_device_lock, flags);
315 td->mode = TICKDEV_MODE_PERIODIC; 315 td->mode = TICKDEV_MODE_PERIODIC;
316 if (dev) { 316 if (dev) {
317 /* 317 /*
@@ -322,7 +322,7 @@ static void tick_shutdown(unsigned int *cpup)
322 clockevents_exchange_device(dev, NULL); 322 clockevents_exchange_device(dev, NULL);
323 td->evtdev = NULL; 323 td->evtdev = NULL;
324 } 324 }
325 spin_unlock_irqrestore(&tick_device_lock, flags); 325 raw_spin_unlock_irqrestore(&tick_device_lock, flags);
326} 326}
327 327
328static void tick_suspend(void) 328static void tick_suspend(void)
@@ -330,9 +330,9 @@ static void tick_suspend(void)
330 struct tick_device *td = &__get_cpu_var(tick_cpu_device); 330 struct tick_device *td = &__get_cpu_var(tick_cpu_device);
331 unsigned long flags; 331 unsigned long flags;
332 332
333 spin_lock_irqsave(&tick_device_lock, flags); 333 raw_spin_lock_irqsave(&tick_device_lock, flags);
334 clockevents_shutdown(td->evtdev); 334 clockevents_shutdown(td->evtdev);
335 spin_unlock_irqrestore(&tick_device_lock, flags); 335 raw_spin_unlock_irqrestore(&tick_device_lock, flags);
336} 336}
337 337
338static void tick_resume(void) 338static void tick_resume(void)
@@ -341,7 +341,7 @@ static void tick_resume(void)
341 unsigned long flags; 341 unsigned long flags;
342 int broadcast = tick_resume_broadcast(); 342 int broadcast = tick_resume_broadcast();
343 343
344 spin_lock_irqsave(&tick_device_lock, flags); 344 raw_spin_lock_irqsave(&tick_device_lock, flags);
345 clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_RESUME); 345 clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_RESUME);
346 346
347 if (!broadcast) { 347 if (!broadcast) {
@@ -350,7 +350,7 @@ static void tick_resume(void)
350 else 350 else
351 tick_resume_oneshot(); 351 tick_resume_oneshot();
352 } 352 }
353 spin_unlock_irqrestore(&tick_device_lock, flags); 353 raw_spin_unlock_irqrestore(&tick_device_lock, flags);
354} 354}
355 355
356/* 356/*
diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
index b1c05bf75ee0..290eefbc1f60 100644
--- a/kernel/time/tick-internal.h
+++ b/kernel/time/tick-internal.h
@@ -6,7 +6,6 @@
6#define TICK_DO_TIMER_BOOT -2 6#define TICK_DO_TIMER_BOOT -2
7 7
8DECLARE_PER_CPU(struct tick_device, tick_cpu_device); 8DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
9extern spinlock_t tick_device_lock;
10extern ktime_t tick_next_period; 9extern ktime_t tick_next_period;
11extern ktime_t tick_period; 10extern ktime_t tick_period;
12extern int tick_do_timer_cpu __read_mostly; 11extern int tick_do_timer_cpu __read_mostly;
diff --git a/kernel/time/tick-oneshot.c b/kernel/time/tick-oneshot.c
index a96c0e2b89cf..0a8a213016f0 100644
--- a/kernel/time/tick-oneshot.c
+++ b/kernel/time/tick-oneshot.c
@@ -50,9 +50,9 @@ int tick_dev_program_event(struct clock_event_device *dev, ktime_t expires,
50 dev->min_delta_ns += dev->min_delta_ns >> 1; 50 dev->min_delta_ns += dev->min_delta_ns >> 1;
51 51
52 printk(KERN_WARNING 52 printk(KERN_WARNING
53 "CE: %s increasing min_delta_ns to %lu nsec\n", 53 "CE: %s increasing min_delta_ns to %llu nsec\n",
54 dev->name ? dev->name : "?", 54 dev->name ? dev->name : "?",
55 dev->min_delta_ns << 1); 55 (unsigned long long) dev->min_delta_ns << 1);
56 56
57 i = 0; 57 i = 0;
58 } 58 }
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 89aed5933ed4..f992762d7f51 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -134,18 +134,13 @@ __setup("nohz=", setup_tick_nohz);
134 * value. We do this unconditionally on any cpu, as we don't know whether the 134 * value. We do this unconditionally on any cpu, as we don't know whether the
135 * cpu, which has the update task assigned is in a long sleep. 135 * cpu, which has the update task assigned is in a long sleep.
136 */ 136 */
137static void tick_nohz_update_jiffies(void) 137static void tick_nohz_update_jiffies(ktime_t now)
138{ 138{
139 int cpu = smp_processor_id(); 139 int cpu = smp_processor_id();
140 struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); 140 struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
141 unsigned long flags; 141 unsigned long flags;
142 ktime_t now;
143
144 if (!ts->tick_stopped)
145 return;
146 142
147 cpumask_clear_cpu(cpu, nohz_cpu_mask); 143 cpumask_clear_cpu(cpu, nohz_cpu_mask);
148 now = ktime_get();
149 ts->idle_waketime = now; 144 ts->idle_waketime = now;
150 145
151 local_irq_save(flags); 146 local_irq_save(flags);
@@ -155,20 +150,17 @@ static void tick_nohz_update_jiffies(void)
155 touch_softlockup_watchdog(); 150 touch_softlockup_watchdog();
156} 151}
157 152
158static void tick_nohz_stop_idle(int cpu) 153static void tick_nohz_stop_idle(int cpu, ktime_t now)
159{ 154{
160 struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); 155 struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
156 ktime_t delta;
161 157
162 if (ts->idle_active) { 158 delta = ktime_sub(now, ts->idle_entrytime);
163 ktime_t now, delta; 159 ts->idle_lastupdate = now;
164 now = ktime_get(); 160 ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
165 delta = ktime_sub(now, ts->idle_entrytime); 161 ts->idle_active = 0;
166 ts->idle_lastupdate = now;
167 ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
168 ts->idle_active = 0;
169 162
170 sched_clock_idle_wakeup_event(0); 163 sched_clock_idle_wakeup_event(0);
171 }
172} 164}
173 165
174static ktime_t tick_nohz_start_idle(struct tick_sched *ts) 166static ktime_t tick_nohz_start_idle(struct tick_sched *ts)
@@ -216,6 +208,7 @@ void tick_nohz_stop_sched_tick(int inidle)
216 struct tick_sched *ts; 208 struct tick_sched *ts;
217 ktime_t last_update, expires, now; 209 ktime_t last_update, expires, now;
218 struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev; 210 struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
211 u64 time_delta;
219 int cpu; 212 int cpu;
220 213
221 local_irq_save(flags); 214 local_irq_save(flags);
@@ -263,7 +256,7 @@ void tick_nohz_stop_sched_tick(int inidle)
263 256
264 if (ratelimit < 10) { 257 if (ratelimit < 10) {
265 printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n", 258 printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n",
266 local_softirq_pending()); 259 (unsigned int) local_softirq_pending());
267 ratelimit++; 260 ratelimit++;
268 } 261 }
269 goto end; 262 goto end;
@@ -275,14 +268,18 @@ void tick_nohz_stop_sched_tick(int inidle)
275 seq = read_seqbegin(&xtime_lock); 268 seq = read_seqbegin(&xtime_lock);
276 last_update = last_jiffies_update; 269 last_update = last_jiffies_update;
277 last_jiffies = jiffies; 270 last_jiffies = jiffies;
271 time_delta = timekeeping_max_deferment();
278 } while (read_seqretry(&xtime_lock, seq)); 272 } while (read_seqretry(&xtime_lock, seq));
279 273
280 /* Get the next timer wheel timer */ 274 if (rcu_needs_cpu(cpu) || printk_needs_cpu(cpu) ||
281 next_jiffies = get_next_timer_interrupt(last_jiffies); 275 arch_needs_cpu(cpu)) {
282 delta_jiffies = next_jiffies - last_jiffies; 276 next_jiffies = last_jiffies + 1;
283
284 if (rcu_needs_cpu(cpu) || printk_needs_cpu(cpu))
285 delta_jiffies = 1; 277 delta_jiffies = 1;
278 } else {
279 /* Get the next timer wheel timer */
280 next_jiffies = get_next_timer_interrupt(last_jiffies);
281 delta_jiffies = next_jiffies - last_jiffies;
282 }
286 /* 283 /*
287 * Do not stop the tick, if we are only one off 284 * Do not stop the tick, if we are only one off
288 * or if the cpu is required for rcu 285 * or if the cpu is required for rcu
@@ -294,22 +291,51 @@ void tick_nohz_stop_sched_tick(int inidle)
294 if ((long)delta_jiffies >= 1) { 291 if ((long)delta_jiffies >= 1) {
295 292
296 /* 293 /*
297 * calculate the expiry time for the next timer wheel
298 * timer
299 */
300 expires = ktime_add_ns(last_update, tick_period.tv64 *
301 delta_jiffies);
302
303 /*
304 * If this cpu is the one which updates jiffies, then 294 * If this cpu is the one which updates jiffies, then
305 * give up the assignment and let it be taken by the 295 * give up the assignment and let it be taken by the
306 * cpu which runs the tick timer next, which might be 296 * cpu which runs the tick timer next, which might be
307 * this cpu as well. If we don't drop this here the 297 * this cpu as well. If we don't drop this here the
308 * jiffies might be stale and do_timer() never 298 * jiffies might be stale and do_timer() never
309 * invoked. 299 * invoked. Keep track of the fact that it was the one
300 * which had the do_timer() duty last. If this cpu is
301 * the one which had the do_timer() duty last, we
302 * limit the sleep time to the timekeeping
303 * max_deferement value which we retrieved
304 * above. Otherwise we can sleep as long as we want.
310 */ 305 */
311 if (cpu == tick_do_timer_cpu) 306 if (cpu == tick_do_timer_cpu) {
312 tick_do_timer_cpu = TICK_DO_TIMER_NONE; 307 tick_do_timer_cpu = TICK_DO_TIMER_NONE;
308 ts->do_timer_last = 1;
309 } else if (tick_do_timer_cpu != TICK_DO_TIMER_NONE) {
310 time_delta = KTIME_MAX;
311 ts->do_timer_last = 0;
312 } else if (!ts->do_timer_last) {
313 time_delta = KTIME_MAX;
314 }
315
316 /*
317 * calculate the expiry time for the next timer wheel
318 * timer. delta_jiffies >= NEXT_TIMER_MAX_DELTA signals
319 * that there is no timer pending or at least extremely
320 * far into the future (12 days for HZ=1000). In this
321 * case we set the expiry to the end of time.
322 */
323 if (likely(delta_jiffies < NEXT_TIMER_MAX_DELTA)) {
324 /*
325 * Calculate the time delta for the next timer event.
326 * If the time delta exceeds the maximum time delta
327 * permitted by the current clocksource then adjust
328 * the time delta accordingly to ensure the
329 * clocksource does not wrap.
330 */
331 time_delta = min_t(u64, time_delta,
332 tick_period.tv64 * delta_jiffies);
333 }
334
335 if (time_delta < KTIME_MAX)
336 expires = ktime_add_ns(last_update, time_delta);
337 else
338 expires.tv64 = KTIME_MAX;
313 339
314 if (delta_jiffies > 1) 340 if (delta_jiffies > 1)
315 cpumask_set_cpu(cpu, nohz_cpu_mask); 341 cpumask_set_cpu(cpu, nohz_cpu_mask);
@@ -342,22 +368,19 @@ void tick_nohz_stop_sched_tick(int inidle)
342 368
343 ts->idle_sleeps++; 369 ts->idle_sleeps++;
344 370
371 /* Mark expires */
372 ts->idle_expires = expires;
373
345 /* 374 /*
346 * delta_jiffies >= NEXT_TIMER_MAX_DELTA signals that 375 * If the expiration time == KTIME_MAX, then
347 * there is no timer pending or at least extremly far 376 * in this case we simply stop the tick timer.
348 * into the future (12 days for HZ=1000). In this case
349 * we simply stop the tick timer:
350 */ 377 */
351 if (unlikely(delta_jiffies >= NEXT_TIMER_MAX_DELTA)) { 378 if (unlikely(expires.tv64 == KTIME_MAX)) {
352 ts->idle_expires.tv64 = KTIME_MAX;
353 if (ts->nohz_mode == NOHZ_MODE_HIGHRES) 379 if (ts->nohz_mode == NOHZ_MODE_HIGHRES)
354 hrtimer_cancel(&ts->sched_timer); 380 hrtimer_cancel(&ts->sched_timer);
355 goto out; 381 goto out;
356 } 382 }
357 383
358 /* Mark expiries */
359 ts->idle_expires = expires;
360
361 if (ts->nohz_mode == NOHZ_MODE_HIGHRES) { 384 if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
362 hrtimer_start(&ts->sched_timer, expires, 385 hrtimer_start(&ts->sched_timer, expires,
363 HRTIMER_MODE_ABS_PINNED); 386 HRTIMER_MODE_ABS_PINNED);
@@ -436,7 +459,11 @@ void tick_nohz_restart_sched_tick(void)
436 ktime_t now; 459 ktime_t now;
437 460
438 local_irq_disable(); 461 local_irq_disable();
439 tick_nohz_stop_idle(cpu); 462 if (ts->idle_active || (ts->inidle && ts->tick_stopped))
463 now = ktime_get();
464
465 if (ts->idle_active)
466 tick_nohz_stop_idle(cpu, now);
440 467
441 if (!ts->inidle || !ts->tick_stopped) { 468 if (!ts->inidle || !ts->tick_stopped) {
442 ts->inidle = 0; 469 ts->inidle = 0;
@@ -450,7 +477,6 @@ void tick_nohz_restart_sched_tick(void)
450 477
451 /* Update jiffies first */ 478 /* Update jiffies first */
452 select_nohz_load_balancer(0); 479 select_nohz_load_balancer(0);
453 now = ktime_get();
454 tick_do_update_jiffies64(now); 480 tick_do_update_jiffies64(now);
455 cpumask_clear_cpu(cpu, nohz_cpu_mask); 481 cpumask_clear_cpu(cpu, nohz_cpu_mask);
456 482
@@ -584,22 +610,18 @@ static void tick_nohz_switch_to_nohz(void)
584 * timer and do not touch the other magic bits which need to be done 610 * timer and do not touch the other magic bits which need to be done
585 * when idle is left. 611 * when idle is left.
586 */ 612 */
587static void tick_nohz_kick_tick(int cpu) 613static void tick_nohz_kick_tick(int cpu, ktime_t now)
588{ 614{
589#if 0 615#if 0
590 /* Switch back to 2.6.27 behaviour */ 616 /* Switch back to 2.6.27 behaviour */
591 617
592 struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); 618 struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
593 ktime_t delta, now; 619 ktime_t delta;
594
595 if (!ts->tick_stopped)
596 return;
597 620
598 /* 621 /*
599 * Do not touch the tick device, when the next expiry is either 622 * Do not touch the tick device, when the next expiry is either
600 * already reached or less/equal than the tick period. 623 * already reached or less/equal than the tick period.
601 */ 624 */
602 now = ktime_get();
603 delta = ktime_sub(hrtimer_get_expires(&ts->sched_timer), now); 625 delta = ktime_sub(hrtimer_get_expires(&ts->sched_timer), now);
604 if (delta.tv64 <= tick_period.tv64) 626 if (delta.tv64 <= tick_period.tv64)
605 return; 627 return;
@@ -608,9 +630,26 @@ static void tick_nohz_kick_tick(int cpu)
608#endif 630#endif
609} 631}
610 632
633static inline void tick_check_nohz(int cpu)
634{
635 struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
636 ktime_t now;
637
638 if (!ts->idle_active && !ts->tick_stopped)
639 return;
640 now = ktime_get();
641 if (ts->idle_active)
642 tick_nohz_stop_idle(cpu, now);
643 if (ts->tick_stopped) {
644 tick_nohz_update_jiffies(now);
645 tick_nohz_kick_tick(cpu, now);
646 }
647}
648
611#else 649#else
612 650
613static inline void tick_nohz_switch_to_nohz(void) { } 651static inline void tick_nohz_switch_to_nohz(void) { }
652static inline void tick_check_nohz(int cpu) { }
614 653
615#endif /* NO_HZ */ 654#endif /* NO_HZ */
616 655
@@ -620,11 +659,7 @@ static inline void tick_nohz_switch_to_nohz(void) { }
620void tick_check_idle(int cpu) 659void tick_check_idle(int cpu)
621{ 660{
622 tick_check_oneshot_broadcast(cpu); 661 tick_check_oneshot_broadcast(cpu);
623#ifdef CONFIG_NO_HZ 662 tick_check_nohz(cpu);
624 tick_nohz_stop_idle(cpu);
625 tick_nohz_update_jiffies();
626 tick_nohz_kick_tick(cpu);
627#endif
628} 663}
629 664
630/* 665/*
diff --git a/kernel/time/timecompare.c b/kernel/time/timecompare.c
index 71e7f1a19156..12f5c55090be 100644
--- a/kernel/time/timecompare.c
+++ b/kernel/time/timecompare.c
@@ -40,7 +40,7 @@ ktime_t timecompare_transform(struct timecompare *sync,
40 40
41 return ns_to_ktime(nsec); 41 return ns_to_ktime(nsec);
42} 42}
43EXPORT_SYMBOL(timecompare_transform); 43EXPORT_SYMBOL_GPL(timecompare_transform);
44 44
45int timecompare_offset(struct timecompare *sync, 45int timecompare_offset(struct timecompare *sync,
46 s64 *offset, 46 s64 *offset,
@@ -89,7 +89,7 @@ int timecompare_offset(struct timecompare *sync,
89 * source time 89 * source time
90 */ 90 */
91 sample.offset = 91 sample.offset =
92 ktime_to_ns(ktime_add(end, start)) / 2 - 92 (ktime_to_ns(end) + ktime_to_ns(start)) / 2 -
93 ts; 93 ts;
94 94
95 /* simple insertion sort based on duration */ 95 /* simple insertion sort based on duration */
@@ -131,7 +131,7 @@ int timecompare_offset(struct timecompare *sync,
131 131
132 return used; 132 return used;
133} 133}
134EXPORT_SYMBOL(timecompare_offset); 134EXPORT_SYMBOL_GPL(timecompare_offset);
135 135
136void __timecompare_update(struct timecompare *sync, 136void __timecompare_update(struct timecompare *sync,
137 u64 source_tstamp) 137 u64 source_tstamp)
@@ -188,4 +188,4 @@ void __timecompare_update(struct timecompare *sync,
188 } 188 }
189 } 189 }
190} 190}
191EXPORT_SYMBOL(__timecompare_update); 191EXPORT_SYMBOL_GPL(__timecompare_update);
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index c3a4e2907eaa..7faaa32fbf4f 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -177,7 +177,7 @@ void timekeeping_leap_insert(int leapsecond)
177{ 177{
178 xtime.tv_sec += leapsecond; 178 xtime.tv_sec += leapsecond;
179 wall_to_monotonic.tv_sec -= leapsecond; 179 wall_to_monotonic.tv_sec -= leapsecond;
180 update_vsyscall(&xtime, timekeeper.clock); 180 update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult);
181} 181}
182 182
183#ifdef CONFIG_GENERIC_TIME 183#ifdef CONFIG_GENERIC_TIME
@@ -337,7 +337,7 @@ int do_settimeofday(struct timespec *tv)
337 timekeeper.ntp_error = 0; 337 timekeeper.ntp_error = 0;
338 ntp_clear(); 338 ntp_clear();
339 339
340 update_vsyscall(&xtime, timekeeper.clock); 340 update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult);
341 341
342 write_sequnlock_irqrestore(&xtime_lock, flags); 342 write_sequnlock_irqrestore(&xtime_lock, flags);
343 343
@@ -488,6 +488,17 @@ int timekeeping_valid_for_hres(void)
488} 488}
489 489
490/** 490/**
491 * timekeeping_max_deferment - Returns max time the clocksource can be deferred
492 *
493 * Caller must observe xtime_lock via read_seqbegin/read_seqretry to
494 * ensure that the clocksource does not change!
495 */
496u64 timekeeping_max_deferment(void)
497{
498 return timekeeper.clock->max_idle_ns;
499}
500
501/**
491 * read_persistent_clock - Return time from the persistent clock. 502 * read_persistent_clock - Return time from the persistent clock.
492 * 503 *
493 * Weak dummy function for arches that do not yet support it. 504 * Weak dummy function for arches that do not yet support it.
@@ -722,6 +733,51 @@ static void timekeeping_adjust(s64 offset)
722 timekeeper.ntp_error_shift; 733 timekeeper.ntp_error_shift;
723} 734}
724 735
736
737/**
738 * logarithmic_accumulation - shifted accumulation of cycles
739 *
740 * This functions accumulates a shifted interval of cycles into
741 * into a shifted interval nanoseconds. Allows for O(log) accumulation
742 * loop.
743 *
744 * Returns the unconsumed cycles.
745 */
746static cycle_t logarithmic_accumulation(cycle_t offset, int shift)
747{
748 u64 nsecps = (u64)NSEC_PER_SEC << timekeeper.shift;
749
750 /* If the offset is smaller then a shifted interval, do nothing */
751 if (offset < timekeeper.cycle_interval<<shift)
752 return offset;
753
754 /* Accumulate one shifted interval */
755 offset -= timekeeper.cycle_interval << shift;
756 timekeeper.clock->cycle_last += timekeeper.cycle_interval << shift;
757
758 timekeeper.xtime_nsec += timekeeper.xtime_interval << shift;
759 while (timekeeper.xtime_nsec >= nsecps) {
760 timekeeper.xtime_nsec -= nsecps;
761 xtime.tv_sec++;
762 second_overflow();
763 }
764
765 /* Accumulate into raw time */
766 raw_time.tv_nsec += timekeeper.raw_interval << shift;;
767 while (raw_time.tv_nsec >= NSEC_PER_SEC) {
768 raw_time.tv_nsec -= NSEC_PER_SEC;
769 raw_time.tv_sec++;
770 }
771
772 /* Accumulate error between NTP and clock interval */
773 timekeeper.ntp_error += tick_length << shift;
774 timekeeper.ntp_error -= timekeeper.xtime_interval <<
775 (timekeeper.ntp_error_shift + shift);
776
777 return offset;
778}
779
780
725/** 781/**
726 * update_wall_time - Uses the current clocksource to increment the wall time 782 * update_wall_time - Uses the current clocksource to increment the wall time
727 * 783 *
@@ -732,6 +788,7 @@ void update_wall_time(void)
732 struct clocksource *clock; 788 struct clocksource *clock;
733 cycle_t offset; 789 cycle_t offset;
734 u64 nsecs; 790 u64 nsecs;
791 int shift = 0, maxshift;
735 792
736 /* Make sure we're fully resumed: */ 793 /* Make sure we're fully resumed: */
737 if (unlikely(timekeeping_suspended)) 794 if (unlikely(timekeeping_suspended))
@@ -745,33 +802,22 @@ void update_wall_time(void)
745#endif 802#endif
746 timekeeper.xtime_nsec = (s64)xtime.tv_nsec << timekeeper.shift; 803 timekeeper.xtime_nsec = (s64)xtime.tv_nsec << timekeeper.shift;
747 804
748 /* normally this loop will run just once, however in the 805 /*
749 * case of lost or late ticks, it will accumulate correctly. 806 * With NO_HZ we may have to accumulate many cycle_intervals
807 * (think "ticks") worth of time at once. To do this efficiently,
808 * we calculate the largest doubling multiple of cycle_intervals
809 * that is smaller then the offset. We then accumulate that
810 * chunk in one go, and then try to consume the next smaller
811 * doubled multiple.
750 */ 812 */
813 shift = ilog2(offset) - ilog2(timekeeper.cycle_interval);
814 shift = max(0, shift);
815 /* Bound shift to one less then what overflows tick_length */
816 maxshift = (8*sizeof(tick_length) - (ilog2(tick_length)+1)) - 1;
817 shift = min(shift, maxshift);
751 while (offset >= timekeeper.cycle_interval) { 818 while (offset >= timekeeper.cycle_interval) {
752 u64 nsecps = (u64)NSEC_PER_SEC << timekeeper.shift; 819 offset = logarithmic_accumulation(offset, shift);
753 820 shift--;
754 /* accumulate one interval */
755 offset -= timekeeper.cycle_interval;
756 clock->cycle_last += timekeeper.cycle_interval;
757
758 timekeeper.xtime_nsec += timekeeper.xtime_interval;
759 if (timekeeper.xtime_nsec >= nsecps) {
760 timekeeper.xtime_nsec -= nsecps;
761 xtime.tv_sec++;
762 second_overflow();
763 }
764
765 raw_time.tv_nsec += timekeeper.raw_interval;
766 if (raw_time.tv_nsec >= NSEC_PER_SEC) {
767 raw_time.tv_nsec -= NSEC_PER_SEC;
768 raw_time.tv_sec++;
769 }
770
771 /* accumulate error between NTP and clock interval */
772 timekeeper.ntp_error += tick_length;
773 timekeeper.ntp_error -= timekeeper.xtime_interval <<
774 timekeeper.ntp_error_shift;
775 } 821 }
776 822
777 /* correct the clock when NTP error is too big */ 823 /* correct the clock when NTP error is too big */
@@ -811,7 +857,7 @@ void update_wall_time(void)
811 update_xtime_cache(nsecs); 857 update_xtime_cache(nsecs);
812 858
813 /* check to see if there is a new clocksource to use */ 859 /* check to see if there is a new clocksource to use */
814 update_vsyscall(&xtime, timekeeper.clock); 860 update_vsyscall(&xtime, timekeeper.clock, timekeeper.mult);
815} 861}
816 862
817/** 863/**
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index 1b5b7aa2fdfd..bdfb8dd1050c 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -84,7 +84,7 @@ print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
84 84
85next_one: 85next_one:
86 i = 0; 86 i = 0;
87 spin_lock_irqsave(&base->cpu_base->lock, flags); 87 raw_spin_lock_irqsave(&base->cpu_base->lock, flags);
88 88
89 curr = base->first; 89 curr = base->first;
90 /* 90 /*
@@ -100,13 +100,13 @@ next_one:
100 100
101 timer = rb_entry(curr, struct hrtimer, node); 101 timer = rb_entry(curr, struct hrtimer, node);
102 tmp = *timer; 102 tmp = *timer;
103 spin_unlock_irqrestore(&base->cpu_base->lock, flags); 103 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
104 104
105 print_timer(m, timer, &tmp, i, now); 105 print_timer(m, timer, &tmp, i, now);
106 next++; 106 next++;
107 goto next_one; 107 goto next_one;
108 } 108 }
109 spin_unlock_irqrestore(&base->cpu_base->lock, flags); 109 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
110} 110}
111 111
112static void 112static void
@@ -150,6 +150,9 @@ static void print_cpu(struct seq_file *m, int cpu, u64 now)
150 P_ns(expires_next); 150 P_ns(expires_next);
151 P(hres_active); 151 P(hres_active);
152 P(nr_events); 152 P(nr_events);
153 P(nr_retries);
154 P(nr_hangs);
155 P_ns(max_hang_time);
153#endif 156#endif
154#undef P 157#undef P
155#undef P_ns 158#undef P_ns
@@ -204,10 +207,12 @@ print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
204 return; 207 return;
205 } 208 }
206 SEQ_printf(m, "%s\n", dev->name); 209 SEQ_printf(m, "%s\n", dev->name);
207 SEQ_printf(m, " max_delta_ns: %lu\n", dev->max_delta_ns); 210 SEQ_printf(m, " max_delta_ns: %llu\n",
208 SEQ_printf(m, " min_delta_ns: %lu\n", dev->min_delta_ns); 211 (unsigned long long) dev->max_delta_ns);
209 SEQ_printf(m, " mult: %lu\n", dev->mult); 212 SEQ_printf(m, " min_delta_ns: %llu\n",
210 SEQ_printf(m, " shift: %d\n", dev->shift); 213 (unsigned long long) dev->min_delta_ns);
214 SEQ_printf(m, " mult: %u\n", dev->mult);
215 SEQ_printf(m, " shift: %u\n", dev->shift);
211 SEQ_printf(m, " mode: %d\n", dev->mode); 216 SEQ_printf(m, " mode: %d\n", dev->mode);
212 SEQ_printf(m, " next_event: %Ld nsecs\n", 217 SEQ_printf(m, " next_event: %Ld nsecs\n",
213 (unsigned long long) ktime_to_ns(dev->next_event)); 218 (unsigned long long) ktime_to_ns(dev->next_event));
@@ -232,10 +237,10 @@ static void timer_list_show_tickdevices(struct seq_file *m)
232#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 237#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
233 print_tickdevice(m, tick_get_broadcast_device(), -1); 238 print_tickdevice(m, tick_get_broadcast_device(), -1);
234 SEQ_printf(m, "tick_broadcast_mask: %08lx\n", 239 SEQ_printf(m, "tick_broadcast_mask: %08lx\n",
235 tick_get_broadcast_mask()->bits[0]); 240 cpumask_bits(tick_get_broadcast_mask())[0]);
236#ifdef CONFIG_TICK_ONESHOT 241#ifdef CONFIG_TICK_ONESHOT
237 SEQ_printf(m, "tick_broadcast_oneshot_mask: %08lx\n", 242 SEQ_printf(m, "tick_broadcast_oneshot_mask: %08lx\n",
238 tick_get_broadcast_oneshot_mask()->bits[0]); 243 cpumask_bits(tick_get_broadcast_oneshot_mask())[0]);
239#endif 244#endif
240 SEQ_printf(m, "\n"); 245 SEQ_printf(m, "\n");
241#endif 246#endif
@@ -252,7 +257,7 @@ static int timer_list_show(struct seq_file *m, void *v)
252 u64 now = ktime_to_ns(ktime_get()); 257 u64 now = ktime_to_ns(ktime_get());
253 int cpu; 258 int cpu;
254 259
255 SEQ_printf(m, "Timer List Version: v0.4\n"); 260 SEQ_printf(m, "Timer List Version: v0.5\n");
256 SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES); 261 SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
257 SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now); 262 SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now);
258 263
diff --git a/kernel/time/timer_stats.c b/kernel/time/timer_stats.c
index ee5681f8d7ec..2f3b585b8d7d 100644
--- a/kernel/time/timer_stats.c
+++ b/kernel/time/timer_stats.c
@@ -86,7 +86,7 @@ static DEFINE_SPINLOCK(table_lock);
86/* 86/*
87 * Per-CPU lookup locks for fast hash lookup: 87 * Per-CPU lookup locks for fast hash lookup:
88 */ 88 */
89static DEFINE_PER_CPU(spinlock_t, lookup_lock); 89static DEFINE_PER_CPU(raw_spinlock_t, tstats_lookup_lock);
90 90
91/* 91/*
92 * Mutex to serialize state changes with show-stats activities: 92 * Mutex to serialize state changes with show-stats activities:
@@ -238,14 +238,14 @@ void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
238 /* 238 /*
239 * It doesnt matter which lock we take: 239 * It doesnt matter which lock we take:
240 */ 240 */
241 spinlock_t *lock; 241 raw_spinlock_t *lock;
242 struct entry *entry, input; 242 struct entry *entry, input;
243 unsigned long flags; 243 unsigned long flags;
244 244
245 if (likely(!timer_stats_active)) 245 if (likely(!timer_stats_active))
246 return; 246 return;
247 247
248 lock = &per_cpu(lookup_lock, raw_smp_processor_id()); 248 lock = &per_cpu(tstats_lookup_lock, raw_smp_processor_id());
249 249
250 input.timer = timer; 250 input.timer = timer;
251 input.start_func = startf; 251 input.start_func = startf;
@@ -253,7 +253,7 @@ void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
253 input.pid = pid; 253 input.pid = pid;
254 input.timer_flag = timer_flag; 254 input.timer_flag = timer_flag;
255 255
256 spin_lock_irqsave(lock, flags); 256 raw_spin_lock_irqsave(lock, flags);
257 if (!timer_stats_active) 257 if (!timer_stats_active)
258 goto out_unlock; 258 goto out_unlock;
259 259
@@ -264,7 +264,7 @@ void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
264 atomic_inc(&overflow_count); 264 atomic_inc(&overflow_count);
265 265
266 out_unlock: 266 out_unlock:
267 spin_unlock_irqrestore(lock, flags); 267 raw_spin_unlock_irqrestore(lock, flags);
268} 268}
269 269
270static void print_name_offset(struct seq_file *m, unsigned long addr) 270static void print_name_offset(struct seq_file *m, unsigned long addr)
@@ -348,9 +348,11 @@ static void sync_access(void)
348 int cpu; 348 int cpu;
349 349
350 for_each_online_cpu(cpu) { 350 for_each_online_cpu(cpu) {
351 spin_lock_irqsave(&per_cpu(lookup_lock, cpu), flags); 351 raw_spinlock_t *lock = &per_cpu(tstats_lookup_lock, cpu);
352
353 raw_spin_lock_irqsave(lock, flags);
352 /* nothing */ 354 /* nothing */
353 spin_unlock_irqrestore(&per_cpu(lookup_lock, cpu), flags); 355 raw_spin_unlock_irqrestore(lock, flags);
354 } 356 }
355} 357}
356 358
@@ -408,7 +410,7 @@ void __init init_timer_stats(void)
408 int cpu; 410 int cpu;
409 411
410 for_each_possible_cpu(cpu) 412 for_each_possible_cpu(cpu)
411 spin_lock_init(&per_cpu(lookup_lock, cpu)); 413 raw_spin_lock_init(&per_cpu(tstats_lookup_lock, cpu));
412} 414}
413 415
414static int __init init_tstats_procfs(void) 416static int __init init_tstats_procfs(void)
generated by cgit v1.2.2 (git 2.25.0) at 2025-12-25 13:35:03 -0500