From 32f64cad97187f4aed50aca3ed1b5a51a00f848b Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Mon, 27 Sep 2021 15:03:26 -0700 Subject: [PATCH] block/mq-deadline: Add an invariant check Check a statistics invariant at module unload time. When running blktests, the invariant is verified every time a request queue is removed and hence is verified at least once per test. Reviewed-by: Damien Le Moal Reviewed-by: Niklas Cassel Cc: Hannes Reinecke Signed-off-by: Bart Van Assche Link: https://lore.kernel.org/r/20210927220328.1410161-3-bvanassche@acm.org Signed-off-by: Jens Axboe --- block/mq-deadline.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/block/mq-deadline.c b/block/mq-deadline.c index c27b4347ca91..2586b3f8c7e9 100644 --- a/block/mq-deadline.c +++ b/block/mq-deadline.c @@ -270,6 +270,12 @@ deadline_move_request(struct deadline_data *dd, struct dd_per_prio *per_prio, deadline_remove_request(rq->q, per_prio, rq); } +/* Number of requests queued for a given priority level. */ +static u32 dd_queued(struct deadline_data *dd, enum dd_prio prio) +{ + return dd_sum(dd, inserted, prio) - dd_sum(dd, completed, prio); +} + /* * deadline_check_fifo returns 0 if there are no expired requests on the fifo, * 1 otherwise. Requires !list_empty(&dd->fifo_list[data_dir]) @@ -539,6 +545,12 @@ static void dd_exit_sched(struct elevator_queue *e) WARN_ON_ONCE(!list_empty(&per_prio->fifo_list[DD_READ])); WARN_ON_ONCE(!list_empty(&per_prio->fifo_list[DD_WRITE])); + WARN_ONCE(dd_queued(dd, prio) != 0, + "statistics for priority %d: i %u m %u d %u c %u\n", + prio, dd_sum(dd, inserted, prio), + dd_sum(dd, merged, prio), + dd_sum(dd, dispatched, prio), + dd_sum(dd, completed, prio)); } free_percpu(dd->stats); @@ -950,12 +962,6 @@ static int dd_async_depth_show(void *data, struct seq_file *m) return 0; } -/* Number of requests queued for a given priority level. */ -static u32 dd_queued(struct deadline_data *dd, enum dd_prio prio) -{ - return dd_sum(dd, inserted, prio) - dd_sum(dd, completed, prio); -} - static int dd_queued_show(void *data, struct seq_file *m) { struct request_queue *q = data;