read_persistent_clock64(9)

💖 read_persistent_clock64 💖

okay bestie, this one’s straight out of the Kernel API Manual, and it’s a tiny timekeeping page with a whole lot of SEE ALSO energy. ✨

🌸 NAME 🌸

read_persistent_clock64 — Return time from the persistent clock.

🎀 SYNOPSIS 🎀

void read_persistent_clock64 (struct timespec64 *ts );

🦋 ARGUMENTS 🦋

• ts — Pointer to the storage for the readout value. that’s literally where the readout goes 💅

✨ DESCRIPTION ✨

okay so real talk: this is a weak dummy function for arches that do not yet support it. No cap. It reads the time from the battery backed persistent clock. 💖

It returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported. 😭

⚠️ also the page literally says: XXX - Do be sure to remove it once all arches implement it. so like… don’t get too attached, bestie 💀

🔥 SEE ALSO 🔥

the kernel file ./kernel/time/timekeeping.c, plus this whole iconic timekeeping group chat:

• 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), adjust_historical_crosststamp(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_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 page, bestie 🫶 — source/version ./kernel/time, dated October 2026, for read_persistent_clock64(9). mwah 💋