All of lore.kernel.org
 help / color / mirror / Atom feed
From: Joseph Qi <joseph.qi@huawei.com>
To: ocfs2-devel@oss.oracle.com
Subject: [Ocfs2-devel] Long io response time doubt
Date: Thu, 12 Nov 2015 11:05:44 +0800	[thread overview]
Message-ID: <56440208.7070809@huawei.com> (raw)

Hi Eric,
You reported an issue about sometime io response time may be long.

From your test case information, I think it was caused by downconvert.
And it seemed reasonable because it had to.

Node 1 wrote file, and node 2 read it. Since you used buffer io, that
was after node 1 had finished written, it might be still in page cache.
So node 1 should downconvert first then node 2 read could continue.
That was why you said it seemed ocfs2_inode_lock_with_page spent most
time. More specifically, it was ocfs2_inode_lock after trying nonblock
lock and returning -EAGAIN.

And this also explained why direct io didn't have the issue, but took
more time.

I am not sure if your test case is the same as what the customer has
reported. I think you should recheck the operations in each node.

And we have reported an case before about DLM handling issue. I am not
sure if it has relations.
https://oss.oracle.com/pipermail/ocfs2-devel/2015-August/011045.html

             reply	other threads:[~2015-11-12  3:05 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-12  3:05 Joseph Qi [this message]
2015-11-12  7:23 ` [Ocfs2-devel] Long io response time doubt Eric Ren
2015-11-12  8:00   ` Joseph Qi
2015-11-12  9:48     ` Eric Ren
2015-11-13  3:31       ` Joseph Qi
2015-11-14  5:23         ` Eric Ren
2015-11-16  1:40           ` Joseph Qi
2015-11-24 10:02             ` Eric Ren
2015-11-24 10:05               ` Eric Ren
2015-11-26  1:34                 ` Joseph Qi
2015-11-26  1:49                   ` Eric Ren

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=56440208.7070809@huawei.com \
    --to=joseph.qi@huawei.com \
    --cc=ocfs2-devel@oss.oracle.com \
    /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.