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Drivers Time EN

Z User edited this page Oct 23, 2026 · 1 revision

Language: English | Drivers-Time

Time sources

Source Driver Command Role
PIT kernel/core/core_timer.c timer THE tick: 100 Hz, scheduler, soft timers
HPET drivers/time/driver_hpet.c hpet high-res counter
ACPI PM timer drivers/time/driver_pmtimer.c pmtimer legacy fallback
TSC drivers/time/driver_tsc.c tsc cycle counter
CMOS RTC drivers/time/driver_cmos_rtc.c rtc wall clock

The tick stays PIT - one 10 ms heartbeat for the whole machine; the others are read-only precision sources (and rtc sets/reads wall time). The E2E timer suite verifies monotonicity and cross-source consistency.

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