From 5b18b5a737600fd20ba2045f320d5926ebbf341a Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Thu, 6 Dec 2018 11:41:19 -0500 Subject: block: delete part_round_stats and switch to less precise counting We want to convert to per-cpu in_flight counters. The function part_round_stats needs the in_flight counter every jiffy, it would be too costly to sum all the percpu variables every jiffy, so it must be deleted. part_round_stats is used to calculate two counters - time_in_queue and io_ticks. time_in_queue can be calculated without part_round_stats, by adding the duration of the I/O when the I/O ends (the value is almost as exact as the previously calculated value, except that time for in-progress I/Os is not counted). io_ticks can be approximated by increasing the value when I/O is started or ended and the jiffies value has changed. If the I/Os take less than a jiffy, the value is as exact as the previously calculated value. If the I/Os take more than a jiffy, io_ticks can drift behind the previously calculated value. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer Signed-off-by: Jens Axboe --- block/partition-generic.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'block/partition-generic.c') diff --git a/block/partition-generic.c b/block/partition-generic.c index 7e663cfb1487..42d6138ac876 100644 --- a/block/partition-generic.c +++ b/block/partition-generic.c @@ -122,9 +122,6 @@ ssize_t part_stat_show(struct device *dev, struct request_queue *q = part_to_disk(p)->queue; unsigned int inflight[2]; - part_stat_lock(); - part_round_stats(q, p); - part_stat_unlock(); part_in_flight(q, p, inflight); return sprintf(buf, "%8lu %8lu %8llu %8u " -- cgit