Commit | Line | Data |
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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
3e51f33f | 2 | /* |
97fb7a0a | 3 | * sched_clock() for unstable CPU clocks |
3e51f33f | 4 | * |
90eec103 | 5 | * Copyright (C) 2008 Red Hat, Inc., Peter Zijlstra |
3e51f33f | 6 | * |
c300ba25 SR |
7 | * Updates and enhancements: |
8 | * Copyright (C) 2008 Red Hat, Inc. Steven Rostedt <srostedt@redhat.com> | |
9 | * | |
3e51f33f PZ |
10 | * Based on code by: |
11 | * Ingo Molnar <mingo@redhat.com> | |
12 | * Guillaume Chazarain <guichaz@gmail.com> | |
13 | * | |
c676329a | 14 | * |
97fb7a0a | 15 | * What this file implements: |
c676329a PZ |
16 | * |
17 | * cpu_clock(i) provides a fast (execution time) high resolution | |
18 | * clock with bounded drift between CPUs. The value of cpu_clock(i) | |
19 | * is monotonic for constant i. The timestamp returned is in nanoseconds. | |
20 | * | |
21 | * ######################### BIG FAT WARNING ########################## | |
22 | * # when comparing cpu_clock(i) to cpu_clock(j) for i != j, time can # | |
23 | * # go backwards !! # | |
24 | * #################################################################### | |
25 | * | |
26 | * There is no strict promise about the base, although it tends to start | |
27 | * at 0 on boot (but people really shouldn't rely on that). | |
28 | * | |
29 | * cpu_clock(i) -- can be used from any context, including NMI. | |
97fb7a0a | 30 | * local_clock() -- is cpu_clock() on the current CPU. |
c676329a | 31 | * |
ef08f0ff PZ |
32 | * sched_clock_cpu(i) |
33 | * | |
97fb7a0a | 34 | * How it is implemented: |
c676329a PZ |
35 | * |
36 | * The implementation either uses sched_clock() when | |
37 | * !CONFIG_HAVE_UNSTABLE_SCHED_CLOCK, which means in that case the | |
38 | * sched_clock() is assumed to provide these properties (mostly it means | |
39 | * the architecture provides a globally synchronized highres time source). | |
40 | * | |
41 | * Otherwise it tries to create a semi stable clock from a mixture of other | |
42 | * clocks, including: | |
43 | * | |
3b03706f | 44 | * - GTOD (clock monotonic) |
3e51f33f PZ |
45 | * - sched_clock() |
46 | * - explicit idle events | |
47 | * | |
c676329a PZ |
48 | * We use GTOD as base and use sched_clock() deltas to improve resolution. The |
49 | * deltas are filtered to provide monotonicity and keeping it within an | |
50 | * expected window. | |
3e51f33f PZ |
51 | * |
52 | * Furthermore, explicit sleep and wakeup hooks allow us to account for time | |
53 | * that is otherwise invisible (TSC gets stopped). | |
54 | * | |
3e51f33f | 55 | */ |
3e51f33f | 56 | |
2c3d103b HD |
57 | /* |
58 | * Scheduler clock - returns current time in nanosec units. | |
59 | * This is default implementation. | |
60 | * Architectures and sub-architectures can override this. | |
61 | */ | |
fa28abed | 62 | notrace unsigned long long __weak sched_clock(void) |
2c3d103b | 63 | { |
92d23f70 R |
64 | return (unsigned long long)(jiffies - INITIAL_JIFFIES) |
65 | * (NSEC_PER_SEC / HZ); | |
2c3d103b | 66 | } |
b6ac23af | 67 | EXPORT_SYMBOL_GPL(sched_clock); |
3e51f33f | 68 | |
46457ea4 | 69 | static DEFINE_STATIC_KEY_FALSE(sched_clock_running); |
c1955a3d | 70 | |
3e51f33f | 71 | #ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK |
acb04058 PZ |
72 | /* |
73 | * We must start with !__sched_clock_stable because the unstable -> stable | |
74 | * transition is accurate, while the stable -> unstable transition is not. | |
75 | * | |
76 | * Similarly we start with __sched_clock_stable_early, thereby assuming we | |
77 | * will become stable, such that there's only a single 1 -> 0 transition. | |
78 | */ | |
555570d7 | 79 | static DEFINE_STATIC_KEY_FALSE(__sched_clock_stable); |
acb04058 | 80 | static int __sched_clock_stable_early = 1; |
35af99e6 | 81 | |
5680d809 | 82 | /* |
698eff63 | 83 | * We want: ktime_get_ns() + __gtod_offset == sched_clock() + __sched_clock_offset |
5680d809 | 84 | */ |
698eff63 PZ |
85 | __read_mostly u64 __sched_clock_offset; |
86 | static __read_mostly u64 __gtod_offset; | |
5680d809 PZ |
87 | |
88 | struct sched_clock_data { | |
89 | u64 tick_raw; | |
90 | u64 tick_gtod; | |
91 | u64 clock; | |
92 | }; | |
93 | ||
94 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct sched_clock_data, sched_clock_data); | |
95 | ||
776f2291 | 96 | static __always_inline struct sched_clock_data *this_scd(void) |
5680d809 PZ |
97 | { |
98 | return this_cpu_ptr(&sched_clock_data); | |
99 | } | |
100 | ||
fa28abed | 101 | notrace static inline struct sched_clock_data *cpu_sdc(int cpu) |
5680d809 PZ |
102 | { |
103 | return &per_cpu(sched_clock_data, cpu); | |
104 | } | |
105 | ||
fa28abed | 106 | notrace int sched_clock_stable(void) |
35af99e6 | 107 | { |
555570d7 | 108 | return static_branch_likely(&__sched_clock_stable); |
35af99e6 PZ |
109 | } |
110 | ||
fa28abed | 111 | notrace static void __scd_stamp(struct sched_clock_data *scd) |
cf15ca8d PZ |
112 | { |
113 | scd->tick_gtod = ktime_get_ns(); | |
114 | scd->tick_raw = sched_clock(); | |
115 | } | |
116 | ||
fa28abed | 117 | notrace static void __set_sched_clock_stable(void) |
35af99e6 | 118 | { |
45aea321 | 119 | struct sched_clock_data *scd; |
5680d809 | 120 | |
45aea321 PZ |
121 | /* |
122 | * Since we're still unstable and the tick is already running, we have | |
123 | * to disable IRQs in order to get a consistent scd->tick* reading. | |
124 | */ | |
125 | local_irq_disable(); | |
126 | scd = this_scd(); | |
5680d809 PZ |
127 | /* |
128 | * Attempt to make the (initial) unstable->stable transition continuous. | |
129 | */ | |
698eff63 | 130 | __sched_clock_offset = (scd->tick_gtod + __gtod_offset) - (scd->tick_raw); |
45aea321 | 131 | local_irq_enable(); |
5680d809 PZ |
132 | |
133 | printk(KERN_INFO "sched_clock: Marking stable (%lld, %lld)->(%lld, %lld)\n", | |
698eff63 PZ |
134 | scd->tick_gtod, __gtod_offset, |
135 | scd->tick_raw, __sched_clock_offset); | |
5680d809 | 136 | |
555570d7 | 137 | static_branch_enable(&__sched_clock_stable); |
4f49b90a | 138 | tick_dep_clear(TICK_DEP_BIT_CLOCK_UNSTABLE); |
d375b4e0 PZ |
139 | } |
140 | ||
cf15ca8d PZ |
141 | /* |
142 | * If we ever get here, we're screwed, because we found out -- typically after | |
143 | * the fact -- that TSC wasn't good. This means all our clocksources (including | |
144 | * ktime) could have reported wrong values. | |
145 | * | |
146 | * What we do here is an attempt to fix up and continue sort of where we left | |
147 | * off in a coherent manner. | |
148 | * | |
149 | * The only way to fully avoid random clock jumps is to boot with: | |
150 | * "tsc=unstable". | |
151 | */ | |
fa28abed | 152 | notrace static void __sched_clock_work(struct work_struct *work) |
71fdb70e | 153 | { |
cf15ca8d PZ |
154 | struct sched_clock_data *scd; |
155 | int cpu; | |
156 | ||
157 | /* take a current timestamp and set 'now' */ | |
158 | preempt_disable(); | |
159 | scd = this_scd(); | |
160 | __scd_stamp(scd); | |
161 | scd->clock = scd->tick_gtod + __gtod_offset; | |
162 | preempt_enable(); | |
163 | ||
164 | /* clone to all CPUs */ | |
165 | for_each_possible_cpu(cpu) | |
166 | per_cpu(sched_clock_data, cpu) = *scd; | |
167 | ||
7708d5f0 | 168 | printk(KERN_WARNING "TSC found unstable after boot, most likely due to broken BIOS. Use 'tsc=unstable'.\n"); |
cf15ca8d PZ |
169 | printk(KERN_INFO "sched_clock: Marking unstable (%lld, %lld)<-(%lld, %lld)\n", |
170 | scd->tick_gtod, __gtod_offset, | |
171 | scd->tick_raw, __sched_clock_offset); | |
172 | ||
71fdb70e PZ |
173 | static_branch_disable(&__sched_clock_stable); |
174 | } | |
175 | ||
176 | static DECLARE_WORK(sched_clock_work, __sched_clock_work); | |
177 | ||
fa28abed | 178 | notrace static void __clear_sched_clock_stable(void) |
35af99e6 | 179 | { |
cf15ca8d PZ |
180 | if (!sched_clock_stable()) |
181 | return; | |
5680d809 | 182 | |
4f49b90a | 183 | tick_dep_set(TICK_DEP_BIT_CLOCK_UNSTABLE); |
cf15ca8d | 184 | schedule_work(&sched_clock_work); |
71fdb70e | 185 | } |
6577e42a | 186 | |
fa28abed | 187 | notrace void clear_sched_clock_stable(void) |
6577e42a | 188 | { |
d375b4e0 PZ |
189 | __sched_clock_stable_early = 0; |
190 | ||
9881b024 | 191 | smp_mb(); /* matches sched_clock_init_late() */ |
d375b4e0 | 192 | |
46457ea4 | 193 | if (static_key_count(&sched_clock_running.key) == 2) |
71fdb70e | 194 | __clear_sched_clock_stable(); |
6577e42a PZ |
195 | } |
196 | ||
fa28abed | 197 | notrace static void __sched_clock_gtod_offset(void) |
5d2a4e91 | 198 | { |
9407f5a7 PZ |
199 | struct sched_clock_data *scd = this_scd(); |
200 | ||
201 | __scd_stamp(scd); | |
202 | __gtod_offset = (scd->tick_raw + __sched_clock_offset) - scd->tick_gtod; | |
5d2a4e91 PT |
203 | } |
204 | ||
205 | void __init sched_clock_init(void) | |
206 | { | |
857baa87 PT |
207 | /* |
208 | * Set __gtod_offset such that once we mark sched_clock_running, | |
209 | * sched_clock_tick() continues where sched_clock() left off. | |
210 | * | |
211 | * Even if TSC is buggered, we're still UP at this point so it | |
212 | * can't really be out of sync. | |
213 | */ | |
9407f5a7 | 214 | local_irq_disable(); |
857baa87 | 215 | __sched_clock_gtod_offset(); |
9407f5a7 | 216 | local_irq_enable(); |
857baa87 | 217 | |
46457ea4 | 218 | static_branch_inc(&sched_clock_running); |
5d2a4e91 | 219 | } |
2e44b7dd PZ |
220 | /* |
221 | * We run this as late_initcall() such that it runs after all built-in drivers, | |
222 | * notably: acpi_processor and intel_idle, which can mark the TSC as unstable. | |
223 | */ | |
224 | static int __init sched_clock_init_late(void) | |
3e51f33f | 225 | { |
46457ea4 | 226 | static_branch_inc(&sched_clock_running); |
d375b4e0 PZ |
227 | /* |
228 | * Ensure that it is impossible to not do a static_key update. | |
229 | * | |
230 | * Either {set,clear}_sched_clock_stable() must see sched_clock_running | |
231 | * and do the update, or we must see their __sched_clock_stable_early | |
232 | * and do the update, or both. | |
233 | */ | |
234 | smp_mb(); /* matches {set,clear}_sched_clock_stable() */ | |
235 | ||
236 | if (__sched_clock_stable_early) | |
237 | __set_sched_clock_stable(); | |
2e44b7dd PZ |
238 | |
239 | return 0; | |
3e51f33f | 240 | } |
2e44b7dd | 241 | late_initcall(sched_clock_init_late); |
3e51f33f | 242 | |
354879bb | 243 | /* |
b342501c | 244 | * min, max except they take wrapping into account |
354879bb PZ |
245 | */ |
246 | ||
776f2291 | 247 | static __always_inline u64 wrap_min(u64 x, u64 y) |
354879bb PZ |
248 | { |
249 | return (s64)(x - y) < 0 ? x : y; | |
250 | } | |
251 | ||
776f2291 | 252 | static __always_inline u64 wrap_max(u64 x, u64 y) |
354879bb PZ |
253 | { |
254 | return (s64)(x - y) > 0 ? x : y; | |
255 | } | |
256 | ||
3e51f33f PZ |
257 | /* |
258 | * update the percpu scd from the raw @now value | |
259 | * | |
260 | * - filter out backward motion | |
354879bb | 261 | * - use the GTOD tick value to create a window to filter crazy TSC values |
3e51f33f | 262 | */ |
776f2291 | 263 | static __always_inline u64 sched_clock_local(struct sched_clock_data *scd) |
3e51f33f | 264 | { |
7b09cc5a | 265 | u64 now, clock, old_clock, min_clock, max_clock, gtod; |
def0a9b2 | 266 | s64 delta; |
3e51f33f | 267 | |
def0a9b2 | 268 | again: |
fb7d4948 | 269 | now = sched_clock_noinstr(); |
def0a9b2 | 270 | delta = now - scd->tick_raw; |
354879bb PZ |
271 | if (unlikely(delta < 0)) |
272 | delta = 0; | |
3e51f33f | 273 | |
def0a9b2 PZ |
274 | old_clock = scd->clock; |
275 | ||
354879bb PZ |
276 | /* |
277 | * scd->clock = clamp(scd->tick_gtod + delta, | |
b342501c IM |
278 | * max(scd->tick_gtod, scd->clock), |
279 | * scd->tick_gtod + TICK_NSEC); | |
354879bb | 280 | */ |
3e51f33f | 281 | |
7b09cc5a PT |
282 | gtod = scd->tick_gtod + __gtod_offset; |
283 | clock = gtod + delta; | |
284 | min_clock = wrap_max(gtod, old_clock); | |
285 | max_clock = wrap_max(old_clock, gtod + TICK_NSEC); | |
3e51f33f | 286 | |
354879bb PZ |
287 | clock = wrap_max(clock, min_clock); |
288 | clock = wrap_min(clock, max_clock); | |
3e51f33f | 289 | |
0f613bfa | 290 | if (!raw_try_cmpxchg64(&scd->clock, &old_clock, clock)) |
def0a9b2 | 291 | goto again; |
56b90612 | 292 | |
def0a9b2 | 293 | return clock; |
3e51f33f PZ |
294 | } |
295 | ||
fb7d4948 | 296 | noinstr u64 local_clock_noinstr(void) |
776f2291 PZ |
297 | { |
298 | u64 clock; | |
299 | ||
300 | if (static_branch_likely(&__sched_clock_stable)) | |
fb7d4948 | 301 | return sched_clock_noinstr() + __sched_clock_offset; |
776f2291 | 302 | |
f31dcb15 | 303 | if (!static_branch_likely(&sched_clock_running)) |
fb7d4948 | 304 | return sched_clock_noinstr(); |
f31dcb15 | 305 | |
776f2291 | 306 | clock = sched_clock_local(this_scd()); |
776f2291 PZ |
307 | |
308 | return clock; | |
309 | } | |
fb7d4948 PZ |
310 | |
311 | u64 local_clock(void) | |
312 | { | |
313 | u64 now; | |
314 | preempt_disable_notrace(); | |
315 | now = local_clock_noinstr(); | |
316 | preempt_enable_notrace(); | |
317 | return now; | |
318 | } | |
776f2291 PZ |
319 | EXPORT_SYMBOL_GPL(local_clock); |
320 | ||
321 | static notrace u64 sched_clock_remote(struct sched_clock_data *scd) | |
3e51f33f | 322 | { |
def0a9b2 PZ |
323 | struct sched_clock_data *my_scd = this_scd(); |
324 | u64 this_clock, remote_clock; | |
325 | u64 *ptr, old_val, val; | |
326 | ||
a1cbcaa9 TG |
327 | #if BITS_PER_LONG != 64 |
328 | again: | |
329 | /* | |
330 | * Careful here: The local and the remote clock values need to | |
331 | * be read out atomic as we need to compare the values and | |
332 | * then update either the local or the remote side. So the | |
333 | * cmpxchg64 below only protects one readout. | |
334 | * | |
335 | * We must reread via sched_clock_local() in the retry case on | |
97fb7a0a | 336 | * 32-bit kernels as an NMI could use sched_clock_local() via the |
a1cbcaa9 | 337 | * tracer and hit between the readout of |
97fb7a0a | 338 | * the low 32-bit and the high 32-bit portion. |
a1cbcaa9 TG |
339 | */ |
340 | this_clock = sched_clock_local(my_scd); | |
341 | /* | |
97fb7a0a IM |
342 | * We must enforce atomic readout on 32-bit, otherwise the |
343 | * update on the remote CPU can hit inbetween the readout of | |
344 | * the low 32-bit and the high 32-bit portion. | |
a1cbcaa9 TG |
345 | */ |
346 | remote_clock = cmpxchg64(&scd->clock, 0, 0); | |
347 | #else | |
348 | /* | |
97fb7a0a IM |
349 | * On 64-bit kernels the read of [my]scd->clock is atomic versus the |
350 | * update, so we can avoid the above 32-bit dance. | |
a1cbcaa9 | 351 | */ |
def0a9b2 PZ |
352 | sched_clock_local(my_scd); |
353 | again: | |
354 | this_clock = my_scd->clock; | |
355 | remote_clock = scd->clock; | |
a1cbcaa9 | 356 | #endif |
def0a9b2 PZ |
357 | |
358 | /* | |
359 | * Use the opportunity that we have both locks | |
360 | * taken to couple the two clocks: we take the | |
361 | * larger time as the latest time for both | |
362 | * runqueues. (this creates monotonic movement) | |
363 | */ | |
364 | if (likely((s64)(remote_clock - this_clock) < 0)) { | |
365 | ptr = &scd->clock; | |
366 | old_val = remote_clock; | |
367 | val = this_clock; | |
3e51f33f | 368 | } else { |
def0a9b2 PZ |
369 | /* |
370 | * Should be rare, but possible: | |
371 | */ | |
372 | ptr = &my_scd->clock; | |
373 | old_val = this_clock; | |
374 | val = remote_clock; | |
3e51f33f | 375 | } |
def0a9b2 | 376 | |
8491d1bd | 377 | if (!try_cmpxchg64(ptr, &old_val, val)) |
def0a9b2 PZ |
378 | goto again; |
379 | ||
380 | return val; | |
3e51f33f PZ |
381 | } |
382 | ||
c676329a PZ |
383 | /* |
384 | * Similar to cpu_clock(), but requires local IRQs to be disabled. | |
385 | * | |
386 | * See cpu_clock(). | |
387 | */ | |
fa28abed | 388 | notrace u64 sched_clock_cpu(int cpu) |
3e51f33f | 389 | { |
b342501c | 390 | struct sched_clock_data *scd; |
def0a9b2 PZ |
391 | u64 clock; |
392 | ||
35af99e6 | 393 | if (sched_clock_stable()) |
698eff63 | 394 | return sched_clock() + __sched_clock_offset; |
a381759d | 395 | |
c5105d76 | 396 | if (!static_branch_likely(&sched_clock_running)) |
857baa87 | 397 | return sched_clock(); |
a381759d | 398 | |
96b3d28b | 399 | preempt_disable_notrace(); |
def0a9b2 | 400 | scd = cpu_sdc(cpu); |
3e51f33f | 401 | |
def0a9b2 PZ |
402 | if (cpu != smp_processor_id()) |
403 | clock = sched_clock_remote(scd); | |
404 | else | |
405 | clock = sched_clock_local(scd); | |
96b3d28b | 406 | preempt_enable_notrace(); |
e4e4e534 | 407 | |
3e51f33f PZ |
408 | return clock; |
409 | } | |
2c923e94 | 410 | EXPORT_SYMBOL_GPL(sched_clock_cpu); |
3e51f33f | 411 | |
fa28abed | 412 | notrace void sched_clock_tick(void) |
3e51f33f | 413 | { |
8325d9c0 | 414 | struct sched_clock_data *scd; |
a381759d | 415 | |
b421b22b PZ |
416 | if (sched_clock_stable()) |
417 | return; | |
418 | ||
c5105d76 | 419 | if (!static_branch_likely(&sched_clock_running)) |
b421b22b PZ |
420 | return; |
421 | ||
2c11dba0 | 422 | lockdep_assert_irqs_disabled(); |
3e51f33f | 423 | |
8325d9c0 | 424 | scd = this_scd(); |
cf15ca8d | 425 | __scd_stamp(scd); |
b421b22b PZ |
426 | sched_clock_local(scd); |
427 | } | |
428 | ||
fa28abed | 429 | notrace void sched_clock_tick_stable(void) |
b421b22b | 430 | { |
b421b22b PZ |
431 | if (!sched_clock_stable()) |
432 | return; | |
433 | ||
434 | /* | |
435 | * Called under watchdog_lock. | |
436 | * | |
437 | * The watchdog just found this TSC to (still) be stable, so now is a | |
438 | * good moment to update our __gtod_offset. Because once we find the | |
439 | * TSC to be unstable, any computation will be computing crap. | |
440 | */ | |
441 | local_irq_disable(); | |
5d2a4e91 | 442 | __sched_clock_gtod_offset(); |
b421b22b | 443 | local_irq_enable(); |
3e51f33f PZ |
444 | } |
445 | ||
446 | /* | |
447 | * We are going deep-idle (irqs are disabled): | |
448 | */ | |
fa28abed | 449 | notrace void sched_clock_idle_sleep_event(void) |
3e51f33f PZ |
450 | { |
451 | sched_clock_cpu(smp_processor_id()); | |
452 | } | |
453 | EXPORT_SYMBOL_GPL(sched_clock_idle_sleep_event); | |
454 | ||
455 | /* | |
f9fccdb9 | 456 | * We just idled; resync with ktime. |
3e51f33f | 457 | */ |
fa28abed | 458 | notrace void sched_clock_idle_wakeup_event(void) |
3e51f33f | 459 | { |
f9fccdb9 PZ |
460 | unsigned long flags; |
461 | ||
462 | if (sched_clock_stable()) | |
463 | return; | |
464 | ||
465 | if (unlikely(timekeeping_suspended)) | |
1c5745aa TG |
466 | return; |
467 | ||
f9fccdb9 | 468 | local_irq_save(flags); |
354879bb | 469 | sched_clock_tick(); |
f9fccdb9 | 470 | local_irq_restore(flags); |
3e51f33f PZ |
471 | } |
472 | EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event); | |
473 | ||
8325d9c0 PZ |
474 | #else /* CONFIG_HAVE_UNSTABLE_SCHED_CLOCK */ |
475 | ||
5d2a4e91 PT |
476 | void __init sched_clock_init(void) |
477 | { | |
46457ea4 | 478 | static_branch_inc(&sched_clock_running); |
bd9f943e | 479 | local_irq_disable(); |
5d2a4e91 | 480 | generic_sched_clock_init(); |
bd9f943e | 481 | local_irq_enable(); |
5d2a4e91 PT |
482 | } |
483 | ||
fa28abed | 484 | notrace u64 sched_clock_cpu(int cpu) |
8325d9c0 | 485 | { |
c5105d76 | 486 | if (!static_branch_likely(&sched_clock_running)) |
8325d9c0 PZ |
487 | return 0; |
488 | ||
489 | return sched_clock(); | |
490 | } | |
9881b024 | 491 | |
b9f8fcd5 | 492 | #endif /* CONFIG_HAVE_UNSTABLE_SCHED_CLOCK */ |
76a2a6ee | 493 | |
545a2bf7 CB |
494 | /* |
495 | * Running clock - returns the time that has elapsed while a guest has been | |
496 | * running. | |
497 | * On a guest this value should be local_clock minus the time the guest was | |
498 | * suspended by the hypervisor (for any reason). | |
499 | * On bare metal this function should return the same as local_clock. | |
500 | * Architectures and sub-architectures can override this. | |
501 | */ | |
fa28abed | 502 | notrace u64 __weak running_clock(void) |
545a2bf7 CB |
503 | { |
504 | return local_clock(); | |
505 | } |