linux-btrfs.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Charles Cazabon <charlesc-lists-btrfs@pyropus.ca>
To: btrfs list <linux-btrfs@vger.kernel.org>
Subject: Re: Oddly slow read performance with near-full largish FS
Date: Wed, 24 Dec 2014 21:14:13 -0600	[thread overview]
Message-ID: <20141225031413.GA5864@pyropus.ca> (raw)
In-Reply-To: <54976811.2060507@pobox.com>

Robert White <rwhite@pobox.com> wrote:
> 
> You have very little free memory.

I think you're mistaken.  Every diagnostic I've looked at says the opposite.
>From 30 seconds ago on the same machine, after unmounting the big btrfs
filesystem (and with a larger xfs one mounted), /proc/meminfo says almost the
entirety of the machine's 16GB is free:

  MemTotal:       16469880 kB
  MemFree:        16005392 kB
  MemAvailable:   15974244 kB
  Buffers:              84 kB
  [...]

> This is called "demand paging",

Yes, I'm aware of how this works.

Charles
-- 
-----------------------------------------------------------------------
Charles Cazabon
GPL'ed software available at:               http://pyropus.ca/software/
-----------------------------------------------------------------------

  reply	other threads:[~2014-12-25  3:09 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-12-17  2:42 Oddly slow read performance with near-full largish FS Charles Cazabon
2014-12-19  8:58 ` Satoru Takeuchi
2014-12-19 16:58   ` Charles Cazabon
2014-12-19 17:33     ` Duncan
2014-12-20  8:53       ` Chris Murphy
2014-12-20 10:03       ` Robert White
2014-12-20 10:57 ` Robert White
2014-12-21 16:32   ` Charles Cazabon
2014-12-21 21:32     ` Robert White
2014-12-21 22:53       ` Charles Cazabon
2014-12-22  0:38         ` Robert White
2014-12-25  3:14           ` Charles Cazabon [this message]
2014-12-22 14:16         ` Austin S Hemmelgarn
2014-12-25  3:15           ` Charles Cazabon
2014-12-22  2:13       ` Satoru Takeuchi
2014-12-25  3:18         ` Charles Cazabon

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=20141225031413.GA5864@pyropus.ca \
    --to=charlesc-lists-btrfs@pyropus.ca \
    --cc=linux-btrfs@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).