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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-11-03 14:13:41 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-11-03 14:13:41 -0800 |
commit | 7b2a4306f9e7d64bb408a6df3bb419500578068a (patch) | |
tree | c8ce206194c47c8bd50ee6b5828e0c734d571200 /kernel/time | |
parent | 316dde2fe95b33657de1fc2db54bfc16aa065790 (diff) | |
parent | 03f136a2074b2b8890da4a24df7104558ad0da48 (diff) | |
download | linux-7b2a4306f9e7d64bb408a6df3bb419500578068a.tar.gz linux-7b2a4306f9e7d64bb408a6df3bb419500578068a.tar.bz2 linux-7b2a4306f9e7d64bb408a6df3bb419500578068a.zip |
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
"The timer departement provides:
- More y2038 work in the area of ntp and pps.
- Optimization of posix cpu timers
- New time related selftests
- Some new clocksource drivers
- The usual pile of fixes, cleanups and improvements"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
timeconst: Update path in comment
timers/x86/hpet: Type adjustments
clocksource/drivers/armada-370-xp: Implement ARM delay timer
clocksource/drivers/tango_xtal: Add new timer for Tango SoCs
clocksource/drivers/imx: Allow timer irq affinity change
clocksource/drivers/exynos_mct: Use container_of() instead of this_cpu_ptr()
clocksource/drivers/h8300_*: Remove unneeded memset()s
clocksource/drivers/sh_cmt: Remove unneeded memset() in sh_cmt_setup()
clocksource/drivers/em_sti: Remove unneeded memset()s
clocksource/drivers/mediatek: Use GPT as sched clock source
clockevents/drivers/mtk: Fix spurious interrupt leading to crash
posix_cpu_timer: Reduce unnecessary sighand lock contention
posix_cpu_timer: Convert cputimer->running to bool
posix_cpu_timer: Check thread timers only when there are active thread timers
posix_cpu_timer: Optimize fastpath_timer_check()
timers, kselftest: Add 'adjtick' test to validate adjtimex() tick adjustments
timers: Use __fls in apply_slack()
clocksource: Remove return statement from void functions
net: sfc: avoid using timespec
ntp/pps: use y2038 safe types in pps_event_time
...
Diffstat (limited to 'kernel/time')
-rw-r--r-- | kernel/time/clocksource.c | 7 | ||||
-rw-r--r-- | kernel/time/hrtimer.c | 2 | ||||
-rw-r--r-- | kernel/time/ntp.c | 16 | ||||
-rw-r--r-- | kernel/time/ntp_internal.h | 2 | ||||
-rw-r--r-- | kernel/time/posix-cpu-timers.c | 63 | ||||
-rw-r--r-- | kernel/time/timeconst.bc | 2 | ||||
-rw-r--r-- | kernel/time/timekeeping.c | 18 | ||||
-rw-r--r-- | kernel/time/timer.c | 13 |
8 files changed, 78 insertions, 45 deletions
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 3a38775b50c2..0d8fe8b8f727 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -479,7 +479,7 @@ static u32 clocksource_max_adjustment(struct clocksource *cs) * return half the number of nanoseconds the hardware counter can technically * cover. This is done so that we can potentially detect problems caused by * delayed timers or bad hardware, which might result in time intervals that - * are larger then what the math used can handle without overflows. + * are larger than what the math used can handle without overflows. */ u64 clocks_calc_max_nsecs(u32 mult, u32 shift, u32 maxadj, u64 mask, u64 *max_cyc) { @@ -595,16 +595,15 @@ static void __clocksource_select(bool skipcur) */ static void clocksource_select(void) { - return __clocksource_select(false); + __clocksource_select(false); } static void clocksource_select_fallback(void) { - return __clocksource_select(true); + __clocksource_select(true); } #else /* !CONFIG_ARCH_USES_GETTIMEOFFSET */ - static inline void clocksource_select(void) { } static inline void clocksource_select_fallback(void) { } diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 457a373e2181..435b8850dd80 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -59,7 +59,7 @@ /* * The timer bases: * - * There are more clockids then hrtimer bases. Thus, we index + * There are more clockids than hrtimer bases. Thus, we index * into the timer bases by the hrtimer_base_type enum. When trying * to reach a base using a clockid, hrtimer_clockid_to_base() * is used to convert from clockid to the proper hrtimer_base_type. diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index df68cb875248..149cc8086aea 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -99,7 +99,7 @@ static time64_t ntp_next_leap_sec = TIME64_MAX; static int pps_valid; /* signal watchdog counter */ static long pps_tf[3]; /* phase median filter */ static long pps_jitter; /* current jitter (ns) */ -static struct timespec pps_fbase; /* beginning of the last freq interval */ +static struct timespec64 pps_fbase; /* beginning of the last freq interval */ static int pps_shift; /* current interval duration (s) (shift) */ static int pps_intcnt; /* interval counter */ static s64 pps_freq; /* frequency offset (scaled ns/s) */ @@ -509,7 +509,7 @@ static DECLARE_DELAYED_WORK(sync_cmos_work, sync_cmos_clock); static void sync_cmos_clock(struct work_struct *work) { struct timespec64 now; - struct timespec next; + struct timespec64 next; int fail = 1; /* @@ -559,7 +559,7 @@ static void sync_cmos_clock(struct work_struct *work) next.tv_nsec -= NSEC_PER_SEC; } queue_delayed_work(system_power_efficient_wq, - &sync_cmos_work, timespec_to_jiffies(&next)); + &sync_cmos_work, timespec64_to_jiffies(&next)); } void ntp_notify_cmos_timer(void) @@ -773,13 +773,13 @@ int __do_adjtimex(struct timex *txc, struct timespec64 *ts, s32 *time_tai) * pps_normtime.nsec has a range of ( -NSEC_PER_SEC / 2, NSEC_PER_SEC / 2 ] * while timespec.tv_nsec has a range of [0, NSEC_PER_SEC) */ struct pps_normtime { - __kernel_time_t sec; /* seconds */ + s64 sec; /* seconds */ long nsec; /* nanoseconds */ }; /* normalize the timestamp so that nsec is in the ( -NSEC_PER_SEC / 2, NSEC_PER_SEC / 2 ] interval */ -static inline struct pps_normtime pps_normalize_ts(struct timespec ts) +static inline struct pps_normtime pps_normalize_ts(struct timespec64 ts) { struct pps_normtime norm = { .sec = ts.tv_sec, @@ -861,7 +861,7 @@ static long hardpps_update_freq(struct pps_normtime freq_norm) pps_errcnt++; pps_dec_freq_interval(); printk_deferred(KERN_ERR - "hardpps: PPSERROR: interval too long - %ld s\n", + "hardpps: PPSERROR: interval too long - %lld s\n", freq_norm.sec); return 0; } @@ -948,7 +948,7 @@ static void hardpps_update_phase(long error) * This code is based on David Mills's reference nanokernel * implementation. It was mostly rewritten but keeps the same idea. */ -void __hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts) +void __hardpps(const struct timespec64 *phase_ts, const struct timespec64 *raw_ts) { struct pps_normtime pts_norm, freq_norm; @@ -969,7 +969,7 @@ void __hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts) } /* ok, now we have a base for frequency calculation */ - freq_norm = pps_normalize_ts(timespec_sub(*raw_ts, pps_fbase)); + freq_norm = pps_normalize_ts(timespec64_sub(*raw_ts, pps_fbase)); /* check that the signal is in the range * [1s - MAXFREQ us, 1s + MAXFREQ us], otherwise reject it */ diff --git a/kernel/time/ntp_internal.h b/kernel/time/ntp_internal.h index 65430504ca26..af924470eac0 100644 --- a/kernel/time/ntp_internal.h +++ b/kernel/time/ntp_internal.h @@ -9,5 +9,5 @@ extern ktime_t ntp_get_next_leap(void); extern int second_overflow(unsigned long secs); extern int ntp_validate_timex(struct timex *); extern int __do_adjtimex(struct timex *, struct timespec64 *, s32 *); -extern void __hardpps(const struct timespec *, const struct timespec *); +extern void __hardpps(const struct timespec64 *, const struct timespec64 *); #endif /* _LINUX_NTP_INTERNAL_H */ diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index 892e3dae0aac..f5e86d282d52 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -249,7 +249,7 @@ void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times) * but barriers are not required because update_gt_cputime() * can handle concurrent updates. */ - WRITE_ONCE(cputimer->running, 1); + WRITE_ONCE(cputimer->running, true); } sample_cputime_atomic(times, &cputimer->cputime_atomic); } @@ -864,6 +864,13 @@ static void check_thread_timers(struct task_struct *tsk, unsigned long long expires; unsigned long soft; + /* + * If cputime_expires is zero, then there are no active + * per thread CPU timers. + */ + if (task_cputime_zero(&tsk->cputime_expires)) + return; + expires = check_timers_list(timers, firing, prof_ticks(tsk)); tsk_expires->prof_exp = expires_to_cputime(expires); @@ -911,7 +918,7 @@ static inline void stop_process_timers(struct signal_struct *sig) struct thread_group_cputimer *cputimer = &sig->cputimer; /* Turn off cputimer->running. This is done without locking. */ - WRITE_ONCE(cputimer->running, 0); + WRITE_ONCE(cputimer->running, false); } static u32 onecputick; @@ -962,6 +969,19 @@ static void check_process_timers(struct task_struct *tsk, unsigned long soft; /* + * If cputimer is not running, then there are no active + * process wide timers (POSIX 1.b, itimers, RLIMIT_CPU). + */ + if (!READ_ONCE(tsk->signal->cputimer.running)) + return; + + /* + * Signify that a thread is checking for process timers. + * Write access to this field is protected by the sighand lock. + */ + sig->cputimer.checking_timer = true; + + /* * Collect the current process totals. */ thread_group_cputimer(tsk, &cputime); @@ -1015,6 +1035,8 @@ static void check_process_timers(struct task_struct *tsk, sig->cputime_expires.sched_exp = sched_expires; if (task_cputime_zero(&sig->cputime_expires)) stop_process_timers(sig); + + sig->cputimer.checking_timer = false; } /* @@ -1117,24 +1139,33 @@ static inline int task_cputime_expired(const struct task_cputime *sample, static inline int fastpath_timer_check(struct task_struct *tsk) { struct signal_struct *sig; - cputime_t utime, stime; - - task_cputime(tsk, &utime, &stime); if (!task_cputime_zero(&tsk->cputime_expires)) { - struct task_cputime task_sample = { - .utime = utime, - .stime = stime, - .sum_exec_runtime = tsk->se.sum_exec_runtime - }; + struct task_cputime task_sample; + task_cputime(tsk, &task_sample.utime, &task_sample.stime); + task_sample.sum_exec_runtime = tsk->se.sum_exec_runtime; if (task_cputime_expired(&task_sample, &tsk->cputime_expires)) return 1; } sig = tsk->signal; - /* Check if cputimer is running. This is accessed without locking. */ - if (READ_ONCE(sig->cputimer.running)) { + /* + * Check if thread group timers expired when the cputimer is + * running and no other thread in the group is already checking + * for thread group cputimers. These fields are read without the + * sighand lock. However, this is fine because this is meant to + * be a fastpath heuristic to determine whether we should try to + * acquire the sighand lock to check/handle timers. + * + * In the worst case scenario, if 'running' or 'checking_timer' gets + * set but the current thread doesn't see the change yet, we'll wait + * until the next thread in the group gets a scheduler interrupt to + * handle the timer. This isn't an issue in practice because these + * types of delays with signals actually getting sent are expected. + */ + if (READ_ONCE(sig->cputimer.running) && + !READ_ONCE(sig->cputimer.checking_timer)) { struct task_cputime group_sample; sample_cputime_atomic(&group_sample, &sig->cputimer.cputime_atomic); @@ -1174,12 +1205,8 @@ void run_posix_cpu_timers(struct task_struct *tsk) * put them on the firing list. */ check_thread_timers(tsk, &firing); - /* - * If there are any active process wide timers (POSIX 1.b, itimers, - * RLIMIT_CPU) cputimer must be running. - */ - if (READ_ONCE(tsk->signal->cputimer.running)) - check_process_timers(tsk, &firing); + + check_process_timers(tsk, &firing); /* * We must release these locks before taking any timer's lock. diff --git a/kernel/time/timeconst.bc b/kernel/time/timeconst.bc index c7388dee8635..c48688904f9f 100644 --- a/kernel/time/timeconst.bc +++ b/kernel/time/timeconst.bc @@ -39,7 +39,7 @@ define fmuls(b,n,d) { } define timeconst(hz) { - print "/* Automatically generated by kernel/timeconst.bc */\n" + print "/* Automatically generated by kernel/time/timeconst.bc */\n" print "/* Time conversion constants for HZ == ", hz, " */\n" print "\n" diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 44d2cc0436f4..b1356b7ae570 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -849,7 +849,7 @@ EXPORT_SYMBOL_GPL(ktime_get_real_seconds); #ifdef CONFIG_NTP_PPS /** - * getnstime_raw_and_real - get day and raw monotonic time in timespec format + * ktime_get_raw_and_real_ts64 - get day and raw monotonic time in timespec format * @ts_raw: pointer to the timespec to be set to raw monotonic time * @ts_real: pointer to the timespec to be set to the time of day * @@ -857,7 +857,7 @@ EXPORT_SYMBOL_GPL(ktime_get_real_seconds); * same time atomically and stores the resulting timestamps in timespec * format. */ -void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real) +void ktime_get_raw_and_real_ts64(struct timespec64 *ts_raw, struct timespec64 *ts_real) { struct timekeeper *tk = &tk_core.timekeeper; unsigned long seq; @@ -868,7 +868,7 @@ void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real) do { seq = read_seqcount_begin(&tk_core.seq); - *ts_raw = timespec64_to_timespec(tk->raw_time); + *ts_raw = tk->raw_time; ts_real->tv_sec = tk->xtime_sec; ts_real->tv_nsec = 0; @@ -877,10 +877,10 @@ void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real) } while (read_seqcount_retry(&tk_core.seq, seq)); - timespec_add_ns(ts_raw, nsecs_raw); - timespec_add_ns(ts_real, nsecs_real); + timespec64_add_ns(ts_raw, nsecs_raw); + timespec64_add_ns(ts_real, nsecs_real); } -EXPORT_SYMBOL(getnstime_raw_and_real); +EXPORT_SYMBOL(ktime_get_raw_and_real_ts64); #endif /* CONFIG_NTP_PPS */ @@ -1674,7 +1674,7 @@ static void timekeeping_adjust(struct timekeeper *tk, s64 offset) /** * accumulate_nsecs_to_secs - Accumulates nsecs into secs * - * Helper function that accumulates a the nsecs greater then a second + * Helper function that accumulates the nsecs greater than a second * from the xtime_nsec field to the xtime_secs field. * It also calls into the NTP code to handle leapsecond processing. * @@ -1726,7 +1726,7 @@ static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset, cycle_t interval = tk->cycle_interval << shift; u64 raw_nsecs; - /* If the offset is smaller then a shifted interval, do nothing */ + /* If the offset is smaller than a shifted interval, do nothing */ if (offset < interval) return offset; @@ -2025,7 +2025,7 @@ int do_adjtimex(struct timex *txc) /** * hardpps() - Accessor function to NTP __hardpps function */ -void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts) +void hardpps(const struct timespec64 *phase_ts, const struct timespec64 *raw_ts) { unsigned long flags; diff --git a/kernel/time/timer.c b/kernel/time/timer.c index 84190f02b521..74591ba9474f 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -461,10 +461,17 @@ void __timer_stats_timer_set_start_info(struct timer_list *timer, void *addr) static void timer_stats_account_timer(struct timer_list *timer) { - if (likely(!timer->start_site)) + void *site; + + /* + * start_site can be concurrently reset by + * timer_stats_timer_clear_start_info() + */ + site = READ_ONCE(timer->start_site); + if (likely(!site)) return; - timer_stats_update_stats(timer, timer->start_pid, timer->start_site, + timer_stats_update_stats(timer, timer->start_pid, site, timer->function, timer->start_comm, timer->flags); } @@ -867,7 +874,7 @@ unsigned long apply_slack(struct timer_list *timer, unsigned long expires) if (mask == 0) return expires; - bit = find_last_bit(&mask, BITS_PER_LONG); + bit = __fls(mask); mask = (1UL << bit) - 1; |