linux-block.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Christoph Hellwig <hch@lst.de>
To: Coly Li <colyli@suse.de>
Cc: axboe@kernel.dk, linux-block@vger.kernel.org,
	linux-bcache@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
	stable@vger.kernel.org
Subject: Re: [PATCH 25/25] bcache: fix bio_{start,end}_io_acct with proper device
Date: Sun, 26 Jul 2020 17:07:02 +0200	[thread overview]
Message-ID: <20200726150702.GA23338@lst.de> (raw)
In-Reply-To: <20200725120039.91071-26-colyli@suse.de>

On Sat, Jul 25, 2020 at 08:00:39PM +0800, Coly Li wrote:
> Commit 85750aeb748f ("bcache: use bio_{start,end}_io_acct") moves the
> io account code to the location after bio_set_dev(bio, dc->bdev) in
> cached_dev_make_request(). Then the account is performed incorrectly on
> backing device, indeed the I/O should be counted to bcache device like
> /dev/bcache0.
> 
> With the mistaken I/O account, iostat does not display I/O counts for
> bcache device and all the numbers go to backing device. In writeback
> mode, the hard drive may have 340K+ IOPS which is impossible and wrong
> for spinning disk.
> 
> This patch introduces bch_bio_start_io_acct() and bch_bio_end_io_acct(),
> which switches bio->bi_disk to bcache device before calling
> bio_start_io_acct() or bio_end_io_acct(). Now the I/Os are counted to
> bcache device, and bcache device, cache device and backing device have
> their correct I/O count information back.

Please switch to use disk_{start,end}_io_acct instead of hacking around
with bi_disk assignments.

  reply	other threads:[~2020-07-26 15:07 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-25 12:00 [PATCH 00/25] bcache patches for Linux v5.9 Coly Li
2020-07-25 12:00 ` [PATCH 01/25] bcache: Fix typo in Kconfig name Coly Li
2020-07-25 12:00 ` [PATCH 02/25] bcache: allocate meta data pages as compound pages Coly Li
2020-07-25 12:00 ` [PATCH 03/25] bcache: journel: use for_each_clear_bit() to simplify the code Coly Li
2020-07-25 12:00 ` [PATCH 04/25] bcache: writeback: Remove unneeded variable i Coly Li
2020-07-25 12:00 ` [PATCH 05/25] bcache: movinggc: Use struct_size() helper in kzalloc() Coly Li
2020-07-25 12:00 ` [PATCH 06/25] bcache: Use struct_size() " Coly Li
2020-07-25 12:00 ` [PATCH 07/25] bcache: avoid nr_stripes overflow in bcache_device_init() Coly Li
2020-07-27 21:24   ` Sasha Levin
2020-07-25 12:00 ` [PATCH 08/25] bcache: fix overflow in offset_to_stripe() Coly Li
2020-07-27 21:24   ` Sasha Levin
2020-07-25 12:00 ` [PATCH 09/25] bcache: add read_super_common() to read major part of super block Coly Li
2020-07-25 12:00 ` [PATCH 10/25] bcache: add more accurate error information in read_super_common() Coly Li
2020-07-25 12:00 ` [PATCH 11/25] bcache: disassemble the big if() checks in bch_cache_set_alloc() Coly Li
2020-07-25 12:00 ` [PATCH 12/25] bcache: fix super block seq numbers comparision in register_cache_set() Coly Li
2020-07-25 12:00 ` [PATCH 13/25] bcache: increase super block version for cache device and backing device Coly Li
2020-07-25 12:00 ` [PATCH 14/25] bcache: move bucket related code into read_super_common() Coly Li
2020-07-25 12:00 ` [PATCH 15/25] bcache: struct cache_sb is only for in-memory super block now Coly Li
2020-07-25 12:00 ` [PATCH 16/25] bcache: introduce meta_bucket_pages() related helper routines Coly Li
2020-07-25 12:00 ` [PATCH 17/25] bcache: handle c->uuids properly for bucket size > 8MB Coly Li
2020-07-25 12:00 ` [PATCH 18/25] bcache: handle cache prio_buckets and disk_buckets " Coly Li
2020-07-25 12:00 ` [PATCH 19/25] bcache: handle cache set verify_ondisk " Coly Li
2020-07-25 12:00 ` [PATCH 20/25] bcache: handle btree node memory allocation " Coly Li
2020-07-25 12:00 ` [PATCH 21/25] bcache: add bucket_size_hi into struct cache_sb_disk for large bucket Coly Li
2020-07-25 12:00 ` [PATCH 22/25] bcache: add sysfs file to display feature sets information of cache set Coly Li
2020-07-25 12:00 ` [PATCH 23/25] bcache: avoid extra memory allocation from mempool c->fill_iter Coly Li
2020-07-25 12:00 ` [PATCH 24/25] bcache: avoid extra memory consumption in struct bbio for large bucket size Coly Li
2020-07-25 12:00 ` [PATCH 25/25] bcache: fix bio_{start,end}_io_acct with proper device Coly Li
2020-07-26 15:07   ` Christoph Hellwig [this message]
2020-07-25 13:39 ` [PATCH 00/25] bcache patches for Linux v5.9 Jens Axboe
2020-07-28 12:14   ` Christoph Hellwig
2020-07-28 12:40     ` Coly Li
2020-07-28 12:41       ` Christoph Hellwig
2020-07-28 15:13       ` Jens Axboe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200726150702.GA23338@lst.de \
    --to=hch@lst.de \
    --cc=axboe@kernel.dk \
    --cc=colyli@suse.de \
    --cc=linux-bcache@vger.kernel.org \
    --cc=linux-block@vger.kernel.org \
    --cc=stable@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).