From: Kazuya Mio <k-mio@sx.jp.nec.com>
To: Jan Kara <jack@suse.cz>
Cc: akpm@linux-foundation.org, adilger.kernel@dilger.ca,
linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: bio splits unnecessarily due to BH_Boundary in ext3 direct I/O
Date: Mon, 01 Apr 2013 17:25:56 +0900 [thread overview]
Message-ID: <51594494.3070207@sx.jp.nec.com> (raw)
In-Reply-To: <20130329171536.GF5913@quack.suse.cz>
2013/03/30 2:15, Jan Kara wrote:
> Sorry for not getting to you earlier. So we agree in our analysis. Do you
> agree with the attached patch? Does it help your workload?
According to your two patches, direct I/O works as the following steps:
1. add sdio->cur_page to sdio->bio by dio_new_bio() or dio_bio_add_page()
2. submit sdio->bio if sdio->boudary is set
3. set the curret page to sdio->cur_page in submit_page_section()
Only one page is submitted separately because of submitting bio before step 3.
For example, we write 52KB data with O_DIRECT, it is ideal that filesystem
submits a bio twice (48KB and 4KB). However, after applying your two patches,
52KB data is split into three bios (44KB, 4KB and 4KB).
Regards,
Kazuya Mio
next prev parent reply other threads:[~2013-04-01 8:34 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-07 8:36 bio splits unnecessarily due to BH_Boundary in ext3 direct I/O Kazuya Mio
2013-03-07 10:48 ` Jan Kara
2013-03-19 8:36 ` Kazuya Mio
2013-03-19 19:31 ` Jan Kara
2013-03-21 8:43 ` Kazuya Mio
2013-03-29 17:15 ` Jan Kara
2013-04-01 8:25 ` Kazuya Mio [this message]
2013-04-09 15:40 ` Jan Kara
2013-04-10 2:59 ` Kazuya Mio
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=51594494.3070207@sx.jp.nec.com \
--to=k-mio@sx.jp.nec.com \
--cc=adilger.kernel@dilger.ca \
--cc=akpm@linux-foundation.org \
--cc=jack@suse.cz \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-fsdevel@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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.