From 699785f5d898965408430e841d10cd1cb2c02a77 Mon Sep 17 00:00:00 2001 From: Daniel Lezcano Date: Mon, 27 May 2019 22:55:21 +0200 Subject: [PATCH 1/1] genirq/timings: Add selftest for next event computation The circular buffers are now validated with selftests. The next interrupt index algorithm which is the hardest part to validate needs extra coverage. Add a selftest which uses the intervals stored in the arrays and insert all the values except the last one. The next event computation must return the same value as the last element which was not inserted. Signed-off-by: Daniel Lezcano Signed-off-by: Thomas Gleixner Cc: andriy.shevchenko@linux.intel.com Link: https://lkml.kernel.org/r/20190527205521.12091-9-daniel.lezcano@linaro.org --- kernel/irq/timings.c | 66 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) diff --git a/kernel/irq/timings.c b/kernel/irq/timings.c index 5b13c2231d4f..e960d7ce7bcc 100644 --- a/kernel/irq/timings.c +++ b/kernel/irq/timings.c @@ -704,6 +704,68 @@ static struct timings_intervals tis[] __initdata = { { intervals4, ARRAY_SIZE(intervals4) }, }; +static int __init irq_timings_test_next_index(struct timings_intervals *ti) +{ + int _buffer[IRQ_TIMINGS_SIZE]; + int buffer[IRQ_TIMINGS_SIZE]; + int index, start, i, count, period_max; + + count = ti->count - 1; + + period_max = count > (3 * PREDICTION_PERIOD_MAX) ? + PREDICTION_PERIOD_MAX : count / 3; + + /* + * Inject all values except the last one which will be used + * to compare with the next index result. + */ + pr_debug("index suite: "); + + for (i = 0; i < count; i++) { + index = irq_timings_interval_index(ti->intervals[i]); + _buffer[i & IRQ_TIMINGS_MASK] = index; + pr_cont("%d ", index); + } + + start = count < IRQ_TIMINGS_SIZE ? 0 : + count & IRQ_TIMINGS_MASK; + + count = min_t(int, count, IRQ_TIMINGS_SIZE); + + for (i = 0; i < count; i++) { + int index = (start + i) & IRQ_TIMINGS_MASK; + buffer[i] = _buffer[index]; + } + + index = irq_timings_next_event_index(buffer, count, period_max); + i = irq_timings_interval_index(ti->intervals[ti->count - 1]); + + if (index != i) { + pr_err("Expected (%d) and computed (%d) next indexes differ\n", + i, index); + return -EINVAL; + } + + return 0; +} + +static int __init irq_timings_next_index_selftest(void) +{ + int i, ret; + + for (i = 0; i < ARRAY_SIZE(tis); i++) { + + pr_info("---> Injecting intervals number #%d (count=%zd)\n", + i, tis[i].count); + + ret = irq_timings_test_next_index(&tis[i]); + if (ret) + break; + } + + return ret; +} + static int __init irq_timings_test_irqs(struct timings_intervals *ti) { struct irqt_stat __percpu *s; @@ -875,6 +937,10 @@ static int __init irq_timings_selftest(void) goto out; ret = irq_timings_irqs_selftest(); + if (ret) + goto out; + + ret = irq_timings_next_index_selftest(); out: pr_info("---------- selftest end with %s -----------\n", ret ? "failure" : "success"); -- 2.20.1