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block: count 'ios' and 'sectors' when io is done for bio-based device 

[ Upstream commit 5f27571382 ]

While using iostat for raid, I observed very strange 'await'
occasionally, and turns out it's due to that 'ios' and 'sectors' is
counted in bdev_start_io_acct(), while 'nsecs' is counted in
bdev_end_io_acct(). I'm not sure why they are ccounted like that
but I think this behaviour is obviously wrong because user will get
wrong disk stats.

Fix the problem by counting 'ios' and 'sectors' when io is done, like
what rq-based device does.

Fixes: 394ffa503b ("blk: introduce generic io stat accounting help function")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230223091226.1135678-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Yu Kuai 2023-02-23 17:12:26 +08:00 committed by Greg Kroah-Hartman
parent a6633022d7
commit b477180587
5 changed files with 17 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
block/blk-core.c
View File

@ -946,16 +946,11 @@ again:
}
}
unsigned long bdev_start_io_acct(struct block_device *bdev,
unsigned int sectors, enum req_op op,
unsigned long bdev_start_io_acct(struct block_device *bdev, enum req_op op,
unsigned long start_time)
{
const int sgrp = op_stat_group(op);
part_stat_lock();
update_io_ticks(bdev, start_time, false);
part_stat_inc(bdev, ios[sgrp]);
part_stat_add(bdev, sectors[sgrp], sectors);
part_stat_local_inc(bdev, in_flight[op_is_write(op)]);
part_stat_unlock();
@ -971,13 +966,12 @@ EXPORT_SYMBOL(bdev_start_io_acct);
*/
unsigned long bio_start_io_acct(struct bio *bio)
{
return bdev_start_io_acct(bio->bi_bdev, bio_sectors(bio),
bio_op(bio), jiffies);
return bdev_start_io_acct(bio->bi_bdev, bio_op(bio), jiffies);
}
EXPORT_SYMBOL_GPL(bio_start_io_acct);
void bdev_end_io_acct(struct block_device *bdev, enum req_op op,
unsigned long start_time)
unsigned int sectors, unsigned long start_time)
{
const int sgrp = op_stat_group(op);
unsigned long now = READ_ONCE(jiffies);
@ -985,6 +979,8 @@ void bdev_end_io_acct(struct block_device *bdev, enum req_op op,
part_stat_lock();
update_io_ticks(bdev, now, true);
part_stat_inc(bdev, ios[sgrp]);
part_stat_add(bdev, sectors[sgrp], sectors);
part_stat_add(bdev, nsecs[sgrp], jiffies_to_nsecs(duration));
part_stat_local_dec(bdev, in_flight[op_is_write(op)]);
part_stat_unlock();
@ -994,7 +990,7 @@ EXPORT_SYMBOL(bdev_end_io_acct);
void bio_end_io_acct_remapped(struct bio *bio, unsigned long start_time,
struct block_device *orig_bdev)
{
bdev_end_io_acct(orig_bdev, bio_op(bio), start_time);
bdev_end_io_acct(orig_bdev, bio_op(bio), bio_sectors(bio), start_time);
}
EXPORT_SYMBOL_GPL(bio_end_io_acct_remapped);

4
drivers/block/zram/zram_drv.c
View File

@ -2108,9 +2108,9 @@ static int zram_rw_page(struct block_device *bdev, sector_t sector,
bv.bv_offset = 0;
start_time = bdev_start_io_acct(bdev->bd_disk->part0,
SECTORS_PER_PAGE, op, jiffies);
op, jiffies);
ret = zram_bvec_rw(zram, &bv, index, offset, op, NULL);
bdev_end_io_acct(bdev->bd_disk->part0, op, start_time);
bdev_end_io_acct(bdev->bd_disk->part0, op, SECTORS_PER_PAGE, start_time);
out:
/*
* If I/O fails, just return error(ie, non-zero) without

6
drivers/md/dm.c
View File

@ -510,10 +510,10 @@ static void dm_io_acct(struct dm_io *io, bool end)
sectors = io->sectors;
if (!end)
bdev_start_io_acct(bio->bi_bdev, sectors, bio_op(bio),
start_time);
bdev_start_io_acct(bio->bi_bdev, bio_op(bio), start_time);
else
bdev_end_io_acct(bio->bi_bdev, bio_op(bio), start_time);
bdev_end_io_acct(bio->bi_bdev, bio_op(bio), sectors,
start_time);
if (static_branch_unlikely(&stats_enabled) &&
unlikely(dm_stats_used(&md->stats))) {

8
drivers/nvme/host/multipath.c
View File

@ -123,9 +123,8 @@ void nvme_mpath_start_request(struct request *rq)
return;
nvme_req(rq)->flags |= NVME_MPATH_IO_STATS;
nvme_req(rq)->start_time = bdev_start_io_acct(disk->part0,
blk_rq_bytes(rq) >> SECTOR_SHIFT,
req_op(rq), jiffies);
nvme_req(rq)->start_time = bdev_start_io_acct(disk->part0, req_op(rq),
jiffies);
}
EXPORT_SYMBOL_GPL(nvme_mpath_start_request);
@ -136,7 +135,8 @@ void nvme_mpath_end_request(struct request *rq)
if (!(nvme_req(rq)->flags & NVME_MPATH_IO_STATS))
return;
bdev_end_io_acct(ns->head->disk->part0, req_op(rq),
nvme_req(rq)->start_time);
blk_rq_bytes(rq) >> SECTOR_SHIFT,
nvme_req(rq)->start_time);
}
void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl)

5
include/linux/blkdev.h
View File

@ -1434,11 +1434,10 @@ static inline void blk_wake_io_task(struct task_struct *waiter)
wake_up_process(waiter);
}
unsigned long bdev_start_io_acct(struct block_device *bdev,
unsigned int sectors, enum req_op op,
unsigned long bdev_start_io_acct(struct block_device *bdev, enum req_op op,
unsigned long start_time);
void bdev_end_io_acct(struct block_device *bdev, enum req_op op,
unsigned long start_time);
unsigned int sectors, unsigned long start_time);
unsigned long bio_start_io_acct(struct bio *bio);
void bio_end_io_acct_remapped(struct bio *bio, unsigned long start_time,