qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Stephane Chazelas <stephane.chazelas@gmail.com>
To: Max Reitz <mreitz@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>,
	qemu-devel@nongnu.org, Qemu-block <qemu-block@nongnu.org>
Subject: Re: [Qemu-devel] [qcow2] how to avoid qemu doing lseek(SEEK_DATA/SEEK_HOLE)?
Date: Wed, 8 Feb 2017 17:16:33 +0000	[thread overview]
Message-ID: <20170208171633.GC19518@chaz.gmail.com> (raw)
In-Reply-To: <11bfda2a-7799-a5d5-4ba0-37b2b9dd92f6@redhat.com>

2017-02-08 15:27:11 +0100, Max Reitz:
[...]
> A bit of a stupid question, but: How is your performance when using
> detect-zeroes=off?
[...]

I did try that. See:

} Note that passing detect-zeroes=off or detect-zeroes=unmap (with
} discard) doesn't help (even though FALLOC_FL_PUNCH_HOLE is
} supported on ZFS on Linux).

In my original message. It makes no difference, I still see
those lseek()s being done.

-- 
Stephane

  reply	other threads:[~2017-02-08 17:16 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-02 12:30 [Qemu-devel] [qcow2] how to avoid qemu doing lseek(SEEK_DATA/SEEK_HOLE)? Stephane Chazelas
2017-02-02 15:23 ` Laszlo Ersek
2017-02-02 16:03   ` Stephane Chazelas
2017-02-07 23:43 ` Max Reitz
2017-02-08 14:06   ` Stephane Chazelas
2017-02-08 14:27     ` Max Reitz
2017-02-08 17:16       ` Stephane Chazelas [this message]
2017-02-08 14:20   ` Stephane Chazelas

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=20170208171633.GC19518@chaz.gmail.com \
    --to=stephane.chazelas@gmail.com \
    --cc=kwolf@redhat.com \
    --cc=mreitz@redhat.com \
    --cc=qemu-block@nongnu.org \
    --cc=qemu-devel@nongnu.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).