public inbox for kvm@vger.kernel.org
 help / color / mirror / Atom feed
From: Christoph Hellwig <hch@infradead.org>
To: Michael Tokarev <mjt@tls.msk.ru>
Cc: Thomas Mueller <thomas@chaschperli.ch>, kvm@vger.kernel.org
Subject: Re: Shouldn't cache=none be the default for drives?
Date: Thu, 8 Apr 2010 06:08:35 -0400	[thread overview]
Message-ID: <20100408100835.GA29089@infradead.org> (raw)
In-Reply-To: <4BBD7215.3080204@msgid.tls.msk.ru>

On Thu, Apr 08, 2010 at 10:05:09AM +0400, Michael Tokarev wrote:
> LVM volumes.  This is because with cache=none, the virtual disk
> image is opened with O_DIRECT flag, which means all I/O bypasses
> host scheduler and buffer cache.

O_DIRECT does not bypass the I/O scheduler, only the page cache.


      parent reply	other threads:[~2010-04-08 10:08 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-04-07 14:39 Shouldn't cache=none be the default for drives? Troels Arvin
2010-04-07 15:17 ` Gordan Bobic
2010-04-08  5:07 ` Thomas Mueller
2010-04-08  6:05   ` Michael Tokarev
2010-04-08  6:09     ` Thomas Mueller
2010-04-08  6:23       ` Thomas Mueller
2010-04-08 10:08     ` Christoph Hellwig [this message]

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=20100408100835.GA29089@infradead.org \
    --to=hch@infradead.org \
    --cc=kvm@vger.kernel.org \
    --cc=mjt@tls.msk.ru \
    --cc=thomas@chaschperli.ch \
    /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