Module perf_counters 

Lightweight TSC-based performance counters for critical kernel paths.

Each counter pair tracks total TSC cycles spent + call count. Use PerfScope (RAII) to instrument a section without touching the hot path more than two rdtsc calls + two relaxed atomic adds.

Structs

PerfScope

Measures elapsed TSC cycles between construction and drop, accumulating into the given counter pair.

PerfStat

Summary of one counter pair, ready for display.

Statics

CTX_SWITCH_COUNT

Post-switch fixup (finish_interrupt_switch).

CTX_SWITCH_TSC

IRQ_TIMER_COUNT

Timer IRQ handler (timer_tick).

IRQ_TIMER_TSC

SCHED_PREEMPT_COUNT

Preemption path (maybe_preempt).

SCHED_PREEMPT_TSC

SCHED_YIELD_COUNT

Scheduler lock acquisition in yield_task.

SCHED_YIELD_TSC

Functions

snapshot

Return a snapshot of all perf counters.