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* Implement CLOCK_TAINathan Whitehorn2025-06-121-1/+9
| | | | | | | | | | | | | | Provide a clock through clock_gettime() that returns the current TAI time (UTC without leap seconds) as a complement to CLOCK_REALTIME. This provides compatibility with Linux, which also provides a CLOCK_TAI since kernel 2.6.26, and this seems to be becoming the standard way to acquire TAI time. Unlike Linux, this code will return EINVAL if the TAI offset (set by ntpd, ptpd, etc.) is not known since it seems pathological for CLOCK_TAI to silently give the wrong (UTC) time if the offset is not known as it does on Linux. Reviewed by: imp Differential Revision: https://reviews.freebsd.org/D46268
* clock: Add a long ticks variable, tickslMark Johnston2025-01-101-2/+2
| | | | | | | | | | | | | | | | | | | | | For compatibility with Linux, it's useful to have a tick counter of width sizeof(long), but our tick counter is an int. Currently the linuxkpi tries paper over this difference, but this cannot really be done reliably, so it's desirable to have a wider tick counter. This change introduces ticksl, keeping the existing ticks variable. Follow a suggestion from kib to avoid having to maintain two separate counters and to avoid converting existing code to use ticksl: change hardclock() to update ticksl instead of ticks, and then use assembler directives to make ticks and ticksl overlap such that loading ticks gives the bottom 32 bits. This makes it possible to use ticksl in the linuxkpi without having to convert any native code, and without making hardclock() more complicated or expensive. Then, the linuxkpi can be modified to use ticksl instead of ticks. Reviewed by: olce, kib, emaste MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D48383
* timerfd: Move implementation from linux compat to sys/kernJake Freeland2023-08-241-0/+2
| | | | | | | | | | | Move the timerfd impelemntation from linux compat code to sys/kern. Use it to implement the new system calls for timerfd. Add a hook to kern_tc to allow timerfd to know when the system time has stepped. Add kqueue support to timerfd. Adjust a few names to be less Linux centric. RelNotes: YES Reviewed by: markj (on irc), imp, kib (with reservations), jhb (slack) Differential Revision: https://reviews.freebsd.org/D38459
* sys: Remove $FreeBSD$: one-line .c patternWarner Losh2023-08-161-2/+0
| | | | Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/
* pps: Round to closest integer in pps_event()Sebastian Huber2023-02-271-1/+3
| | | | | | | | | | | | | | The comment above bintime2timespec() says: When converting between timestamps on parallel timescales of differing resolutions it is historical and scientific practice to round down. However, the delta_nsec value is a time difference and not a timestamp. Also the rounding errors accumulate in the frequency accumulator, see hardpps(). So, rounding to the closest integer is probably slightly better. Reviewed by: imp Pull Request: https://github.com/freebsd/freebsd-src/pull/604
* pps: Simplify the nsec calculation in pps_event()Sebastian Huber2023-02-271-10/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Let A be the current calculation of the frequency accumulator (pps_fcount) update in pps_event() scale = (uint64_t)1 << 63; scale /= captc->tc_frequency; scale *= 2; bt.sec = 0; bt.frac = 0; bintime_addx(&bt, scale * tcount); bintime2timespec(&bt, &ts); hardpps(tsp, ts.tv_nsec + 1000000000 * ts.tv_sec); and hardpps(..., delta_nsec): u_nsec = delta_nsec; if (u_nsec > (NANOSECOND >> 1)) u_nsec -= NANOSECOND; else if (u_nsec < -(NANOSECOND >> 1)) u_nsec += NANOSECOND; pps_fcount += u_nsec; This change introduces a new calculation which is slightly simpler and more straight forward. Name it B. Consider the following sample values with a tcount of 2000000100 and a tc_frequency of 2000000000 (2GHz). For A, the scale is 9223372036. Then scale * tcount is 18446744994337203600 which is larger than UINT64_MAX (= 18446744073709551615). The result is 920627651984 == 18446744994337203600 % UINT64_MAX. Since all operands are unsigned the result is well defined through modulo arithmetic. The result of bintime2timespec(&bt, &ts) is 49. This is equal to the correct result 1000000049 % NANOSECOND. In hardpps(), both conditional statements are not executed and pps_fcount is incremented by 49. For the new calculation B, we have 1000000000 * tcount is 2000000100000000000 which is less than UINT64_MAX. This yields after the division with tc_frequency the correct result of 1000000050 for delta_nsec. In hardpps(), the first conditional statement is executed and pps_fcount is incremented by 50. This shows that both methods yield roughly the same results. However, method B is easier to understand and requires fewer conditional statements. Reviewed by: imp Pull Request: https://github.com/freebsd/freebsd-src/pull/604
* pps: Directly assign the timestamps in pps_event()Sebastian Huber2023-02-271-4/+2
| | | | | Reviewed by: imp Pull Request: https://github.com/freebsd/freebsd-src/pull/604
* pps: Move pcount assignment in pps_event()Sebastian Huber2023-02-271-4/+4
| | | | | | | Move the pseq increment. This makes it possible to reuse registers earlier. Reviewed by: imp Pull Request: https://github.com/freebsd/freebsd-src/pull/604
* pps: Simplify capture and event processingSebastian Huber2023-02-271-18/+20
| | | | | | | | | | | | | | Use local variables for the captured timehand and timecounter in pps_event(). This fixes a potential issue in the nsec preparation for hardpps(). Here the timecounter was accessed through the captured timehand after the generation was checked. Make a snapshot of the relevent timehand values early in pps_event(). Check the timehand generation only once during the capture and event processing. Use atomic_thread_fence_acq() similar to the other readers. Reviewed by: imp Pull Request: https://github.com/freebsd/freebsd-src/pull/604
* pps: Load timecounter once in pps_capture()Sebastian Huber2023-02-271-1/+3
| | | | | | | | This ensures that the timecounter and the tc_get_timecount handler belong together. Reviewed by: imp Pull Request: https://github.com/freebsd/freebsd-src/pull/604
* set_cputicker: use a boolMitchell Horne2022-06-231-3/+3
| | | | | | | | | | | The third argument to this function indicates whether the supplied ticker is fixed or variable, i.e. requiring calibration. Give this argument a type and name that better conveys this purpose. Reviewed by: kib, markj MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D35459
* kern_tc.c/cputick2usec() (which is used to calculate cputime fromfirk2022-03-211-9/+3
| | | | | | | | | | | | | | | | | cpu ticks) has some imprecision and, worse, huge timestep (about 20 minutes on 4GHz CPU) near 53.4 days of elapsed time. kern_time.c/cputick2timespec() (it is used for clock_gettime() for querying process or thread consumed cpu time) Uses cputick2usec() and then needlessly converting usec to nsec, obviously losing precision even with fixed cputick2usec(). kern_time.c/kern_clock_getres() uses some weird (anyway wrong) formula for getting cputick resolution. PR: 262215 Reviewed by: gnn Differential Revision: https://reviews.freebsd.org/D34558
* kern_tc: unify timecounter to bintime delta conversionAndriy Gapon2021-11-301-21/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are two places where we convert from a timecounter delta to a bintime delta: tc_windup and bintime_off. Both functions use the same calculations when the timecounter delta is small. But for a large delta (greater than approximately an equivalent of 1 second) the calculations were different. Both functions use approximate calculations based on th_scale that avoid division. Both produce values slightly greater than a true value, calculated with division by tc_frequency, would be. tc_windup is slightly more accurate, so its result is closer to the true value and, thus, smaller than bintime_off result. As a consequence there can be a jump back in time when time hands are switched after a long period of time (a large delta). Just before the switch the time would be calculated with a large delta from th_offset_count in bintime_off. tc_windup does the switch using its own calculations of a new th_offset using the large delta. As explained earlier, the new th_offset may end up being less than the previously produced binuptime. So, for a period of time new binuptime values may be "back in time" comparing to values just before the switch. Such a jump must never happen. All the code assumes that the uptime is monotonically nondecreasing and some code works incorrectly when that assumption is broken. For example, we have observed sleepq_timeout() ignoring a timeout when the sbinuptime value obtained by the callout code was greater than the expiration value, but the sbinuptime obtained in sleepq_timeout() was less than it. In that case the target thread would never get woken up. The unified calculations should ensure the monotonic property of the uptime. The problem is quite rare as normally tc_windup should be called HZ times per second (typically 1000 or 100). But it may happen in VMs on very busy hypervisors where a VM's virtual CPU may not get an execution time slot for a second or more. Reviewed by: kib MFC after: 2 weeks Sponsored by: Panzura LLC
* timecounter: Initialize tc_lock earlierMark Johnston2021-11-191-1/+2
| | | | | | | | | | | | | Hyper-V wants to register its MSR-based timecounter during SI_SUB_HYPERVISOR, before SI_SUB_LOCK, since an emulated 8254 may not be available for DELAY(). So we cannot use MTX_SYSINIT to initialize the timecounter lock. PR: 259878 Reviewed by: kib MFC after: 3 days Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D33014
* timecounter: Load the currently selected tc once in tc_windup()Mark Johnston2021-10-291-7/+9
| | | | | | | | Reported by: Sebastian Huber <sebastian.huber@embedded-brains.de> Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D32729
* kern_tc.c: Scaling/large delta recalculationSebastian Huber2021-10-281-38/+50
| | | | | | | | | | | | | | | | | | | | | This change is a slight performance optimization for systems with a slow 64-bit division. The th->th_scale and th->th_large_delta values only depend on the timecounter frequency and the th->th_adjustment. The timecounter frequency of a timehand only changes when a new timecounter is activated for the timehand. The th->th_adjustment is only changed by the NTP second update. The NTP second update is not done for every call of tc_windup(). Move the code block to recalculate the scaling factor and the large delta of a timehand to the new helper function recalculate_scaling_factor_and_large_delta(). Call recalculate_scaling_factor_and_large_delta() when a new timecounter is activated and a NTP second update occurred. MFC after: 1 week
* timecounter: Lock the timecounter listMark Johnston2021-10-181-10/+30
| | | | | | | | | | | | | | | | | Timecounter registration is dynamic, i.e., there is no requirement that timecounters must be registered during single-threaded boot. Loadable drivers may in principle register timecounters (which can be switched to automatically). Timecounters cannot be unregistered, though this could be implemented. Registered timecounters belong to a global linked list. Add a mutex to synchronize insertions and the traversals done by (mpsafe) sysctl handlers. No functional change intended. Reviewed by: imp, kib MFC after: 2 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D32511
* timecounter: Let kern.timecounter.stepwarnings be set as a tunableMark Johnston2021-10-091-1/+1
| | | | MFC after: 1 week
* Remove "All Rights Reserved" from FreeBSD Foundation sys/ copyrightsEd Maste2021-08-081-1/+0
| | | | | | | These ones were unambiguous cases where the Foundation was the only listed copyright holder (in the associated license block). Sponsored by: The FreeBSD Foundation
* kern: clarify boot timeWarner Losh2021-05-051-1/+7
| | | | | | | | | | | | | | In FreeBSD, the current time is computed from uptime + boottime. Uptime is a continuous, smooth function that's monotonically increasing. To effect changes to the current time, boottime is adjusted. boottime is mutable and shouldn't be cached against future need. Document the current implementation, with the caveat that we may stop stepping boottime on resume in the future and will step uptime instead (noted in the commit message, but not in the code). Sponsored by: Netflix Reviewed by: phk, rpokala Differential Revision: https://reviews.freebsd.org/D30116
* Make kern.timecounter.hardware tunableKonstantin Belousov2021-03-081-6/+16
| | | | | | | Noted and reviewed by: kevans MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential revision: https://reviews.freebsd.org/D29122
* Add ddb 'show timecounter' command.Konstantin Belousov2021-01-181-0/+30
| | | | | MFC after: 1 week Sponsored by: The FreeBSD Foundation
* Changes that improve DTrace FBT reliability on freebsd/arm64:Robert Watson2021-01-111-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Implement a dtrace_getnanouptime(), matching the existing dtrace_getnanotime(), to avoid DTrace calling out to a potentially instrumentable function. (These should probably both be under KDTRACE_HOOKS. Also, it's not clear to me that they are correct implementations for the DTrace thread time functions they are used in .. fixes for another commit.) - Don't allow FBT to instrument functions involved in EL1 exception handling that are involved in FBT trap processing: handle_el1h_sync() and do_el1h_sync(). - Don't allow FBT to instrument DDB and KDB functions, as that makes it rather harder to debug FBT problems. Prior to these changes, use of FBT on FreeBSD/arm64 rapidly led to kernel panics due to recursion in DTrace. Reliable FBT on FreeBSD/arm64 is reliant on another change from @andrew to have the aarch64 instrumentor more carefully check that instructions it replaces are against the stack pointer, which can otherwise lead to memory corruption. That change remains under review. MFC after: 2 weeks Reviewed by: andrew, kp, markj (earlier version), jrtc27 (earlier version) Differential revision: https://reviews.freebsd.org/D27766
* Remove double-calls to tc_get_timecount() to warm timecounters.Konstantin Belousov2020-06-101-3/+0
| | | | | | | | | | | | It seems that second call does not add any useful state change for all implemented timecounters. Discussed with: bde Sponsored by: The FreeBSD Foundation MFC after: 3 weeks Notes: svn path=/head/; revision=362033
* Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many)Pawel Biernacki2020-02-261-13/+24
| | | | | | | | | | | | | | | | | | | r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are still not MPSAFE (or already are but aren’t properly marked). Use it in preparation for a general review of all nodes. This is non-functional change that adds annotations to SYSCTL_NODE and SYSCTL_PROC nodes using one of the soon-to-be-required flags. Mark all obvious cases as MPSAFE. All entries that haven't been marked as MPSAFE before are by default marked as NEEDGIANT Approved by: kib (mentor, blanket) Commented by: kib, gallatin, melifaro Differential Revision: https://reviews.freebsd.org/D23718 Notes: svn path=/head/; revision=358333
* Consolidate read code for timecounters and fix possible overflow inKonstantin Belousov2020-02-141-145/+87
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | bintime()/binuptime(). The algorithm to read the consistent snapshot of current timehand is repeated in each accessor, including the details proper rollup detection and synchronization with the writer. In fact there are only two different kind of readers: one for bintime()/binuptime() which has to do the in-place calculation, and another kind which fetches some member from struct timehand. Extract the logic into type-checked macros, GETTHBINTIME() for bintime calculation, and GETTHMEMBER() for safe read of a structure' member. This way, the synchronization is only written in bintime_off() and getthmember(). In bintime_off(), use overflow-safe calculation of th_scale * delta(timecounter). In tc_windup, pre-calculate the min delta value which overflows and require slow algorithm, into the new timehands th_large_delta member. This part with overflow fix was written by Bruce Evans. Reported by: Mark Millard <marklmi@yahoo.com> (the overflow issue) Tested by: pho Discussed with: emaste Sponsored by: The FreeBSD Foundation (kib) MFC after: 3 weeks Notes: svn path=/head/; revision=357948
* Remove duplicated empty lines from kern/*.cMateusz Guzik2020-01-301-1/+0
| | | | | | | No functional changes. Notes: svn path=/head/; revision=357312
* Initialize timehands linkage much earlier.Konstantin Belousov2019-09-091-12/+22
| | | | | | | | | Reported and tested by: trasz Sponsored by: The FreeBSD Foundation MFC after: 1 week Notes: svn path=/head/; revision=352060
* Make timehands count selectable at boottime.Konstantin Belousov2019-09-091-8/+20
| | | | | | | | | | Tested by: O'Connor, Daniel <darius@dons.net.au> Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D21563 Notes: svn path=/head/; revision=352059
* Instead of using an incomplete list of platforms that uses 64bits time_tOlivier Houchard2019-01-131-1/+2
| | | | | | | | in 32bits mode, special case amd64, as i386 is the only arch that still uses 32bits time_t. Notes: svn path=/head/; revision=342978
* Make timespecadd(3) and friends publicAlan Somers2018-07-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | The timespecadd(3) family of macros were imported from NetBSD back in r35029. However, they were initially guarded by #ifdef _KERNEL. In the meantime, we have grown at least 28 syscalls that use timespecs in some way, leading many programs both inside and outside of the base system to redefine those macros. It's better just to make the definitions public. Our kernel currently defines two-argument versions of timespecadd and timespecsub. NetBSD, OpenBSD, and FreeDesktop.org's libbsd, however, define three-argument versions. Solaris also defines a three-argument version, but only in its kernel. This revision changes our definition to match the common three-argument version. Bump _FreeBSD_version due to the breaking KPI change. Discussed with: cem, jilles, ian, bde Differential Revision: https://reviews.freebsd.org/D14725 Notes: svn path=/head/; revision=336914
* Create a new macro for static DPCPU data.Andrew Turner2018-07-051-2/+2
| | | | | | | | | | | | | | | | | On arm64 (and possible other architectures) we are unable to use static DPCPU data in kernel modules. This is because the compiler will generate PC-relative accesses, however the runtime-linker expects to be able to relocate these. In preparation to fix this create two macros depending on if the data is global or static. Reviewed by: bz, emaste, markj Sponsored by: ABT Systems Ltd Differential Revision: https://reviews.freebsd.org/D16140 Notes: svn path=/head/; revision=336007
* tc: bcopy -> memcpyMateusz Guzik2018-05-041-1/+1
| | | | Notes: svn path=/head/; revision=333267
* Move most of the contents of opt_compat.h to opt_global.h.Brooks Davis2018-04-061-1/+0
| | | | | | | | | | | | | | | | | | | | | opt_compat.h is mentioned in nearly 180 files. In-progress network driver compabibility improvements may add over 100 more so this is closer to "just about everywhere" than "only some files" per the guidance in sys/conf/options. Keep COMPAT_LINUX32 in opt_compat.h as it is confined to a subset of sys/compat/linux/*.c. A fake _COMPAT_LINUX option ensure opt_compat.h is created on all architectures. Move COMPAT_LINUXKPI to opt_dontuse.h as it is only used to control the set of compiled files. Reviewed by: kib, cem, jhb, jtl Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D14941 Notes: svn path=/head/; revision=332122
* Use atomic_load(9) to read ppsinfo sequence numbers.Konstantin Belousov2017-12-191-4/+4
| | | | | | | | | | | | | In this case volatile qualifiers enusre that a compiler does not optimize the accesses out. Reviewed by: alc, jhb Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D13534 Notes: svn path=/head/; revision=326973
* SPDX: use the Beerware identifier.Pedro F. Giffuni2017-11-301-0/+2
| | | | Notes: svn path=/head/; revision=326408
* The th_bintime, th_microtime and th_nanotime members of the timehandKonstantin Belousov2017-10-111-3/+1
| | | | | | | | | | | | | | | all cache the last system time (uptime + boottime). Only the format differs. Do not re-calculate the bintime and simply use the value used to calculate the microtime and nanotime. Group all the updates under the relevant comment. Remove obsoleted XXX part. Submitted by: Sebastian Huber <sebastian.huber@embedded-brains.de> MFC after: 1 week Notes: svn path=/head/; revision=324528
* Add missing pieces of r315280Eric van Gyzen2017-03-141-0/+10
| | | | | | | | | | | | | | | | | I moved this branch from github to a private server, and pulled from the wrong one when committing r315280, so I failed to include two recent commits. Thankfully, they were only cosmetic and were included in the review. Specifically: Add documentation, polish comments, and improve style(9). Tested by: pho (r315280) MFC after: 2 weeks Sponsored by: Dell EMC Differential Revision: https://reviews.freebsd.org/D9791 Notes: svn path=/head/; revision=315287
* When the RTC is adjusted, reevaluate absolute sleep times based on the RTCEric van Gyzen2017-03-141-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | POSIX 2008 says this about clock_settime(2): If the value of the CLOCK_REALTIME clock is set via clock_settime(), the new value of the clock shall be used to determine the time of expiration for absolute time services based upon the CLOCK_REALTIME clock. This applies to the time at which armed absolute timers expire. If the absolute time requested at the invocation of such a time service is before the new value of the clock, the time service shall expire immediately as if the clock had reached the requested time normally. Setting the value of the CLOCK_REALTIME clock via clock_settime() shall have no effect on threads that are blocked waiting for a relative time service based upon this clock, including the nanosleep() function; nor on the expiration of relative timers based upon this clock. Consequently, these time services shall expire when the requested relative interval elapses, independently of the new or old value of the clock. When the real-time clock is adjusted, such as by clock_settime(3), wake any threads sleeping until an absolute real-clock time. Such a sleep is indicated by a non-zero td_rtcgen. The sleep functions will set that field to zero and return zero to tell the caller to reevaluate its sleep duration based on the new value of the clock. At present, this affects the following functions: pthread_cond_timedwait(3) pthread_mutex_timedlock(3) pthread_rwlock_timedrdlock(3) pthread_rwlock_timedwrlock(3) sem_timedwait(3) sem_clockwait_np(3) I'm working on adding clock_nanosleep(2), which will also be affected. Reported by: Sebastian Huber <sebastian.huber@embedded-brains.de> Reviewed by: jhb, kib MFC after: 2 weeks Relnotes: yes Sponsored by: Dell EMC Differential Revision: https://reviews.freebsd.org/D9791 Notes: svn path=/head/; revision=315280
* Add labels to sysctls related to clocks.Ed Schouten2016-12-141-2/+2
| | | | | | | | | | | | | | | | | | | | | Sysctls like kern.eventtimer.et.*.quality currently embed the name of the clock device. This is problematic for the Prometheus metrics exporter for two reasons: - Some of those clocks have dashes in their names, which Prometheus doesn't allow to be used in metric names. - It doesn't allow for extracting the same property of all clocks on the system from within a single query. Attach these nodes to have a label, so that the Prometheus metrics exporter gives these metric a uniform name with the name of the clock attached as a label. Reviewed by: cem Differential Revision: https://reviews.freebsd.org/D8775 Notes: svn path=/head/; revision=310053
* Implement userspace gettimeofday(2) with HPET timecounter.Konstantin Belousov2016-08-171-5/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Right now, userspace (fast) gettimeofday(2) on x86 only works for RDTSC. For older machines, like Core2, where RDTSC is not C2/C3 invariant, and which fall to HPET hardware, this means that the call has both the penalty of the syscall and of the uncached hw behind the QPI or PCIe connection to the sought bridge. Nothing can me done against the access latency, but the syscall overhead can be removed. System already provides mappable /dev/hpetX devices, which gives straight access to the HPET registers page. Add yet another algorithm to the x86 'vdso' timehands. Libc is updated to handle both RDTSC and HPET. For HPET, the index of the hpet device to mmap is passed from kernel to userspace, index might be changed and libc invalidates its mapping as needed. Remove cpu_fill_vdso_timehands() KPI, instead require that timecounters which can be used from userspace, to provide tc_fill_vdso_timehands{,32}() methods. Merge i386 and amd64 libc/<arch>/sys/__vdso_gettc.c into one source file in the new libc/x86/sys location. __vdso_gettc() internal interface is changed to move timecounter algorithm detection into the MD code. Measurements show that RDTSC even with the syscall overhead is faster than userspace HPET access. But still, userspace HPET is three-four times faster than syscall HPET on several Core2 and SandyBridge machines. Tested by: Howard Su <howard0su@gmail.com> Sponsored by: The FreeBSD Foundation MFC after: 1 month Differential revision: https://reviews.freebsd.org/D7473 Notes: svn path=/head/; revision=304285
* Cache getbintime(9) answer in timehands, similarly to getnanotime(9)Konstantin Belousov2016-07-301-10/+8
| | | | | | | | | | | and getmicrotime(9). Suggested and reviewed by: bde (previous version) Sponsored by: The FreeBSD Foundation MFC after: 1 month Notes: svn path=/head/; revision=303548
* Prevent parallel tc_windup() calls, both parallel top-level calls fromKonstantin Belousov2016-07-271-33/+64
| | | | | | | | | | | | | | | | | | | | | | | | | setclock() and from simultaneous top-level and interrupt. For this, tc_windup() is protected with a tc_setclock_mtx spinlock, in the try mode when called from hardclock interrupt. If spinlock cannot be obtained without spinning from the interrupt context, this means that top-level executes tc_windup() on other core and our try may be avoided. The boottimebin and boottime variables should be adjusted from tc_windup(). To be correct, they must be part of the timehands and read using lockless protocol. Remove the globals and reimplement the getboottime(9)/getboottimebin(9) KPI using the timehands read protocol. Tested by: pho (as part of the whole patch) Reviewed by: jhb (same) Discussed wit: bde Sponsored by: The FreeBSD Foundation MFC after: 1 month X-Differential revision: https://reviews.freebsd.org/D7302 Notes: svn path=/head/; revision=303387
* Style.Konstantin Belousov2016-07-271-2/+2
| | | | | | | | | Sponsored by: The FreeBSD Foundation MFC after: 1 month X-Differential revision: https://reviews.freebsd.org/D7302 Notes: svn path=/head/; revision=303384
* Reduce number of timehands to just two. This is useful becauseKonstantin Belousov2016-07-271-18/+8
| | | | | | | | | | | | | | | | consumers can now be only one tc_windup() call late. Use C99 initialization. Tested by: pho (as part of the whole patch) Reviewed by: jhb (same) Discussed with: bde Sponsored by: The FreeBSD Foundation MFC after: 1 month X-Differential revision: https://reviews.freebsd.org/D7302 Notes: svn path=/head/; revision=303383
* Hide the boottime and bootimebin globals, provide the getboottime(9)Konstantin Belousov2016-07-271-19/+40
| | | | | | | | | | | | | | | | | | | | | | | | | and getboottimebin(9) KPI. Change consumers of boottime to use the KPI. The variables were renamed to avoid shadowing issues with local variables of the same name. Issue is that boottime* should be adjusted from tc_windup(), which requires them to be members of the timehands structure. As a preparation, this commit only introduces the interface. Some uses of boottime were found doubtful, e.g. NLM uses boottime to identify the system boot instance. Arguably the identity should not change on the leap second adjustment, but the commit is about the timekeeping code and the consumers were kept bug-to-bug compatible. Tested by: pho (as part of the bigger patch) Reviewed by: jhb (same) Discussed with: bde Sponsored by: The FreeBSD Foundation MFC after: 1 month X-Differential revision: https://reviews.freebsd.org/D7302 Notes: svn path=/head/; revision=303382
* sys/kern: spelling fixes in comments.Pedro F. Giffuni2016-04-291-1/+1
| | | | | | | No functional change. Notes: svn path=/head/; revision=298819
* Define `fhard` in pps_event(..) only when PPS_SYNC is defined to muteEnji Cooper2015-11-021-1/+8
| | | | | | | | | | an -Wunused-but-set-variable warning Reported by: FreeBSD_HEAD_amd64_gcc4.9 jenkins job Sponsored by: EMC / Isilon Storage Division Notes: svn path=/head/; revision=290257
* Use per-cpu values for base and last in tc_cpu_ticks(). The valuesKonstantin Belousov2015-09-251-7/+14
| | | | | | | | | | | | | | | | | | are updated lockess, different CPUs write its own view of timecounter state. The critical section is done for safety, callers of tc_cpu_ticks() are supposed to already enter critical section, or to own a spinlock. The change fixes sporadical reports of too high values reported for the (W)CPU on platforms that do not provide cpu ticker and use tc_cpu_ticks(), in particular, arm*. Diagnosed and reviewed by: jhb Sponsored by: The FreeBSD Foundation MFC after: 1 week Notes: svn path=/head/; revision=288216
* If a specific timecounter has been chosen via sysctl, and a new timecounterIan Lepore2015-08-121-5/+13
| | | | | | | | | | | with higher quality registers (presumably in a module that has just been loaded), do not undo the user's choice by switching to the new timecounter. Document that behavior, and also the fact that there is no way to unregister a timecounter (and thus no way to unload a module containing one). Notes: svn path=/head/; revision=286701
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