[PATCH v2 2/4] block/mq-deadline: Add an invariant check
From: Bart Van Assche <bvanassche@acm.org>
Date: 2021-09-27 22:03:57
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
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 <redacted> Reviewed-by: Niklas Cassel <redacted> Cc: Hannes Reinecke <hare@suse.de> Signed-off-by: Bart Van Assche <bvanassche@acm.org> --- 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;