From 8cd5b8fc00716fb71f6b32d594b38a8f286d6c20 Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Wed, 25 Mar 2020 16:07:08 +0300 Subject: [PATCH] block/diskstats: replace time_in_queue with sum of request times Column "time_in_queue" in diskstats is supposed to show total waiting time of all requests. I.e. value should be equal to the sum of times from other columns. But this is not true, because column "time_in_queue" is counted separately in jiffies rather than in nanoseconds as other times. This patch removes redundant counter for "time_in_queue" and shows total time of read, write, discard and flush requests. Signed-off-by: Konstantin Khlebnikov Signed-off-by: Jens Axboe --- block/bio.c | 1 - block/blk-core.c | 1 - block/genhd.c | 13 ++++++++++--- include/linux/genhd.h | 1 - 4 files changed, 10 insertions(+), 6 deletions(-) diff --git a/block/bio.c b/block/bio.c index 68f65ef2ceba..bc9152977bf0 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1811,7 +1811,6 @@ void generic_end_io_acct(struct request_queue *q, int req_op, update_io_ticks(part, now, true); part_stat_add(part, nsecs[sgrp], jiffies_to_nsecs(duration)); - part_stat_add(part, time_in_queue, duration); part_dec_in_flight(q, part, op_is_write(req_op)); part_stat_unlock(); diff --git a/block/blk-core.c b/block/blk-core.c index 4401b30a1751..eaf6cb3887e6 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1340,7 +1340,6 @@ void blk_account_io_done(struct request *req, u64 now) update_io_ticks(part, jiffies, true); part_stat_inc(part, ios[sgrp]); part_stat_add(part, nsecs[sgrp], now - req->start_time_ns); - part_stat_add(part, time_in_queue, nsecs_to_jiffies64(now - req->start_time_ns)); part_dec_in_flight(req->q, part, rq_data_dir(req)); hd_struct_put(part); diff --git a/block/genhd.c b/block/genhd.c index 9eb981f7e5a4..792356e922a1 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -110,7 +110,6 @@ static void part_stat_read_all(struct hd_struct *part, struct disk_stats *stat) } stat->io_ticks += ptr->io_ticks; - stat->time_in_queue += ptr->time_in_queue; } } #else /* CONFIG_SMP */ @@ -1265,7 +1264,11 @@ ssize_t part_stat_show(struct device *dev, (unsigned int)div_u64(stat.nsecs[STAT_WRITE], NSEC_PER_MSEC), inflight, jiffies_to_msecs(stat.io_ticks), - jiffies_to_msecs(stat.time_in_queue), + (unsigned int)div_u64(stat.nsecs[STAT_READ] + + stat.nsecs[STAT_WRITE] + + stat.nsecs[STAT_DISCARD] + + stat.nsecs[STAT_FLUSH], + NSEC_PER_MSEC), stat.ios[STAT_DISCARD], stat.merges[STAT_DISCARD], (unsigned long long)stat.sectors[STAT_DISCARD], @@ -1559,7 +1562,11 @@ static int diskstats_show(struct seq_file *seqf, void *v) NSEC_PER_MSEC), inflight, jiffies_to_msecs(stat.io_ticks), - jiffies_to_msecs(stat.time_in_queue), + (unsigned int)div_u64(stat.nsecs[STAT_READ] + + stat.nsecs[STAT_WRITE] + + stat.nsecs[STAT_DISCARD] + + stat.nsecs[STAT_FLUSH], + NSEC_PER_MSEC), stat.ios[STAT_DISCARD], stat.merges[STAT_DISCARD], stat.sectors[STAT_DISCARD], diff --git a/include/linux/genhd.h b/include/linux/genhd.h index b0c588d1aa29..790fdc3e0b3d 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -46,7 +46,6 @@ struct disk_stats { unsigned long ios[NR_STAT_GROUPS]; unsigned long merges[NR_STAT_GROUPS]; unsigned long io_ticks; - unsigned long time_in_queue; local_t in_flight[2]; };