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| author | Bart Van Assche <bvanassche@acm.org> | 2021-09-27 15:03:26 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-10-18 06:17:02 -0600 |
| commit | 32f64cad97187f4aed50aca3ed1b5a51a00f848b (patch) | |
| tree | 625b78c6956618e99cec9bbd0c467c30b3761a0a /block/mq-deadline.c | |
| parent | e2c7275dc0fe3cba6a3de5a5f4c98f923e3d9d14 (diff) | |
| download | lwn-32f64cad97187f4aed50aca3ed1b5a51a00f848b.tar.gz lwn-32f64cad97187f4aed50aca3ed1b5a51a00f848b.zip | |
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 <damien.lemoal@wdc.com>
Reviewed-by: Niklas Cassel <Niklas.Cassel@wdc.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20210927220328.1410161-3-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/mq-deadline.c')
| -rw-r--r-- | block/mq-deadline.c | 18 |
1 files 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; |