From: Bart Van Assche <bvanassche@acm.org>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
Jaegeuk Kim <jaegeuk@kernel.org>,
Bart Van Assche <bvanassche@acm.org>,
Damien Le Moal <damien.lemoal@wdc.com>,
Niklas Cassel <Niklas.Cassel@wdc.com>,
Hannes Reinecke <hare@suse.de>
Subject: [PATCH 2/4] block/mq-deadline: Add an invariant check
Date: Thu, 23 Sep 2021 16:26:53 -0700 [thread overview]
Message-ID: <20210923232655.3907383-2-bvanassche@acm.org> (raw)
In-Reply-To: <20210923232655.3907383-1-bvanassche@acm.org>
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.
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Niklas Cassel <Niklas.Cassel@wdc.com>
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 b1175e4560ad..6deb4306bcf3 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;
next prev parent reply other threads:[~2021-09-23 23:27 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-23 23:23 [PATCH 0/4] Restore I/O priority support in the mq-deadline scheduler Bart Van Assche
2021-09-23 23:26 ` [PATCH 1/4] block/mq-deadline: Improve request accounting further Bart Van Assche
2021-09-23 23:26 ` Bart Van Assche [this message]
2021-09-24 10:54 ` [PATCH 2/4] block/mq-deadline: Add an invariant check Damien Le Moal
2021-09-27 15:53 ` Niklas Cassel
2021-09-23 23:26 ` [PATCH 3/4] block/mq-deadline: Stop using per-CPU counters Bart Van Assche
2021-09-24 10:58 ` Damien Le Moal
2021-09-25 2:59 ` Bart Van Assche
2021-09-27 0:19 ` Damien Le Moal
2021-09-27 2:38 ` Bart Van Assche
2021-09-27 3:41 ` Damien Le Moal
2021-09-27 15:53 ` Niklas Cassel
2021-09-23 23:26 ` [PATCH 4/4] block/mq-deadline: Prioritize high-priority requests Bart Van Assche
2021-09-24 11:08 ` Damien Le Moal
2021-09-27 20:03 ` Bart Van Assche
2021-09-24 10:54 ` [PATCH 1/4] block/mq-deadline: Improve request accounting further Damien Le Moal
2021-09-27 15:53 ` Niklas Cassel
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