adjust_hist..._crosststamp(9)

💖 adjust_hist..._crosststamp(9) 💖

hii bestie!! this is the Kernel API Manual page for adjust_hist..._crosststamp(9), and it's lowkey all about adjusting a crosstimestamp from before the current interval. it's giving timekeeping lore, but make it cute 🫶

✨ NAME ✨

adjust_historical_crosststamp — adjust crosstimestamp previous to current interval

🌸 SYNOPSIS 🌸

int adjust_historical_crosststamp (struct system_time_snapshot *history , u64 partial_history_cycles , u64 total_history_cycles , bool discontinuity , struct system_device_crosststamp *ts );

🎀 ARGUMENTS 🎀

• history — Snapshot representing start of history. 🕰️
• partial_history_cycles — Cycle offset into history (fractional part).
• total_history_cycles — Total history length in cycles.
• discontinuity — True indicates clock was set on history period. ⚠️
• ts — Cross timestamp that should be adjusted using partial/total ratio.

🦋 DESCRIPTION 🦋

okay so this helper function is used by get_device_system_crosststamp to correct the crosstimestamp corresponding to the start of the current interval to the system counter value (timestamp point) provided by the driver. literally that's its whole job, and it ate. 💅

the total_history_* quantities are the total history starting at the provided reference point and ending at the start of the current interval. the cycle count between the driver timestamp point and the start of the current interval is partial_history_cycles. periodt.

🌈 SEE ALSO 🌈

the whole timekeeping friend group is here, no cap:

• Kernel file ./kernel/time/timekeeping.c — struct tk_fast(9)
• tk_setup_internals(9)
• update_fast_timekeeper(9)
• ktime_get_mono_fast_ns(9)
• ktime_get_raw_fast_ns(9)
• ktime_get_boot_fast_ns(9)
• ktime_get_tai_fast_ns(9)
• ktime_get_real_fast_ns(9)
• halt_fast_timekeeper(9)
• pvclock_gtod_register_notifier(9)
• pvclock_gtod_unregister_notifier(9)
• timekeeping_forward_now(9)
• ktime_get_real_ts64(9)
• ktime_mono_to_any(9)
• ktime_get_raw(9)
• ktime_get_ts64(9)
• ktime_get_seconds(9)
• ktime_get_real_seconds(9)
• __ktime_get_real_seconds(9)
• ktime_get_snapshot_id(9)
• ktime_real_to_base_clock(9)
• get_device_system_crosststamp(9)
• timekeeping_clocksource_has_base(9)
• do_settimeofday64(9)
• __timekeeping_inject_offset(9)
• timekeeping_notify(9)
• ktime_get_raw_ts64(9)
• timekeeping_valid_for_hres(9)
• timekeeping_max_deferment(9)
• read_persistent_clock64(9)
• read_persistent_wall_and_boot_offset(9)
• __timekeeping_inject_sleeptime(9)
• timekeeping_inject_sleeptime64(9)
• timekeeping_resume(9)
• update_wall_time(9)
• getboottime64(9)
• ktime_get_coarse_real_ts64_mg(9)
• ktime_get_real_ts64_mg(9)
• ktime_get_update_offsets_now(9)
• random_get_entropy_fallback(9)
• do_adjtimex(9)
• hardpps(9)
• ktime_get_aux(9)
• ktime_get_aux_ts64(9)

that's the whole page, bestie 🫶 source: ./kernel/time, date: October 2026 — for adjust_hist..._crosststamp(9). mwah 💋✨