github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-08-04 22:38:46 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph
ca1ec8bfac
linux/kernel/time
History
David Woodhouse ca1ec8bfac timekeeping: Add clocksource read_snapshot() method and hw_cycles to snapshot 
Add a read_snapshot() callback to struct clocksource which returns the
derived clocksource value while also providing the underlying hardware
counter reading and the related clocksource ID.

This allows ktime_get_snapshot_id() to populate new hw_cycles and hw_csid
fields in struct system_time_snapshot.

For clocksources that are derived from an underlying counter (e.g., Hyper-V
TSC page scales TSC to 10MHz, kvmclock scales TSC to 1GHz), this provides
atomic access to both the derived value needed for timekeeping
calculations, and the raw hardware counter needed by consumers like KVM's
master clock and the vmclock PTP driver.

[ tglx: Reworked it slightly ]

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Assisted-by: Kiro:claude-opus-4.6-1m
Link: https://patch.msgid.link/20260526230635.136914-1-dwmw2@infradead.org
Link: https://patch.msgid.link/20260529195558.202568489@kernel.org
2026-06-04 11:04:18 +02:00
..
.kunitconfig time/kunit: Add .kunitconfig 2026-02-24 08:41:51 +01:00
alarmtimer.c Merge branch 'timers/urgent' into timers/core 2026-04-11 07:58:33 +02:00
clockevents.c clockevents: Add missing resets of the next_event_forced flag 2026-04-16 21:22:04 +02:00
clocksource-wdtest.c clocksource: Rewrite watchdog code completely 2026-03-20 13:36:32 +01:00
clocksource.c clocksource: Rewrite watchdog code completely 2026-03-20 13:36:32 +01:00
hrtimer.c Merge branch 'timers/urgent' into timers/core 2026-04-11 07:58:33 +02:00
itimer.c timers/itimer: Avoid direct access to hrtimer clockbase 2025-09-09 12:27:17 +02:00
jiffies.c Linux 7.0-rc4 2026-03-21 08:02:36 +01:00
Kconfig Update to the VDSO subsystem: 2026-04-14 10:53:44 -07:00
Makefile timens: Remove dependency on the vDSO 2026-03-26 15:44:23 +01:00
namespace_internal.h timens: Remove dependency on the vDSO 2026-03-26 15:44:23 +01:00
namespace_vdso.c mm.git review status for linus..mm-stable 2026-04-15 12:59:16 -07:00
namespace.c timens: Use task_lock guard in timens_get*() 2026-04-01 17:13:36 +02:00
ntp_internal.h ntp: Rename __do_adjtimex() to ntp_adjtimex() 2025-06-19 14:28:23 +02:00
ntp.c ntp: Use ktime_get_ntp_seconds() 2025-06-19 14:28:24 +02:00
posix-clock.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
posix-cpu-timers.c hrtimer: Store time as ktime_t in restart block 2025-11-14 16:31:19 +01:00
posix-stubs.c posix-timers: Get rid of [COMPAT_]SYS_NI() uses 2023-12-20 21:30:27 -08:00
posix-timers.c posix-timers: Fix stale function name in comment 2026-03-28 14:18:13 +01:00
posix-timers.h timekeeping: Add minimal posix-timers support for auxiliary clocks 2025-06-27 20:13:12 +02:00
sched_clock.c time/sched_clock: Use ACCESS_PRIVATE() to evaluate hrtimer::function 2026-01-13 18:08:57 +01:00
sleep_timeout.c treewide, timers: Rename from_timer() to timer_container_of() 2025-06-08 09:07:37 +02:00
test_udelay.c time: Add MODULE_DESCRIPTION() to time test modules 2024-06-03 11:18:50 +02:00
tick-broadcast-hrtimer.c clockevents: Remove redundant CLOCK_EVT_FEAT_KTIME 2026-02-27 16:40:06 +01:00
tick-broadcast.c clockevents: Add missing resets of the next_event_forced flag 2026-04-16 21:22:04 +02:00
tick-common.c clockevents: Prevent timer interrupt starvation 2026-04-10 22:45:38 +02:00
tick-internal.h cpufreq: ondemand: Simplify idle cputime granularity test 2026-01-28 22:24:58 +01:00
tick-legacy.c timekeeping: remove xtime_update 2020-10-30 21:57:07 +01:00
tick-oneshot.c treewide: Update email address 2026-01-11 06:09:11 -10:00
tick-sched.c Merge branch 'timers/urgent' into timers/core 2026-04-11 07:58:33 +02:00
tick-sched.h tick/sched: Fix struct tick_sched doc warnings 2024-04-01 10:36:35 +02:00
time_test.c time/kunit: Document handling of negative years of is_leap() 2026-02-02 12:37:54 +01:00
time.c time/jiffies: Mark jiffies_64_to_clock_t() notrace 2026-03-11 10:33:12 +01:00
timeconst.bc
timeconv.c time: Improve performance of time64_to_tm() 2021-06-24 11:51:59 +02:00
timecounter.c time/timecounter: Inline timecounter_cyc2time() 2025-12-15 20:16:49 +01:00
timekeeping_debug.c timekeeping: Add percpu counter for tracking floor swap events 2024-10-10 10:20:46 +02:00
timekeeping_internal.h timekeeping: Provide ktime_get_ntp_seconds() 2025-06-19 14:28:23 +02:00
timekeeping.c timekeeping: Add clocksource read_snapshot() method and hw_cycles to snapshot 2026-06-04 11:04:18 +02:00
timekeeping.h timekeeping: Provide infrastructure for coupled clockevents 2026-02-27 16:40:08 +01:00
timer_list.c timer_list: Print offset as signed integer 2026-03-12 12:15:54 +01:00
timer_migration.c cgroup: Fixes for v7.0-rc2 2026-03-03 14:25:18 -08:00
timer_migration.h timers/migration: Rename 'online' bit to 'available' 2025-11-20 20:17:31 +01:00
timer.c timers: Get this_cpu once while clearing the idle state 2026-03-24 23:21:30 +01:00
vsyscall.c vdso/vsyscall: Avoid slow division loop in auxiliary clock update 2025-09-03 11:55:11 +02:00