Linux perf "irq/sec"

perf top has a value "irq/sec"

linux/tools/perf/builtin-top.c, perf_top__mmap_read_idx(), top->samples is increased whenever read a sample.

linux/tools/perf/util/top.c, perf_top__header_snprintf(), the irq/sec is the value of samples_per_sec, which is calculated by:
        float samples_per_sec = top->samples / top->delay_secs;

Therefor, the irq/sec is, sample rate. Period.