From: Christoph Hellwig <hch@lst.de>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>,
keith.busch@intel.com, kwolf@redhat.com, mreitz@redhat.com,
qemu-devel@nongnu.org, qemu-block@nongnu.org
Subject: Re: [Qemu-devel] [PATCH] nvme: Implement Write Zeroes
Date: Fri, 5 May 2017 12:10:26 +0200 [thread overview]
Message-ID: <20170505101026.GA7095@lst.de> (raw)
In-Reply-To: <f8a6ae1b-fc48-4c15-1b15-bd966b00c00e@redhat.com>
On Fri, May 05, 2017 at 12:03:40PM +0200, Paolo Bonzini wrote:
> While that's allowed and it makes sense indeed on SSDs, for QEMU's
> typical usage it can lead to fragmentation and worse performance. On
> extent-based file systems, write zeroes without deallocate can be
> implemented very efficiently with FALLOC_FL_ZERO_RANGE, and there's no
> reason not to do it.
Ok..
> Is there anything backwards-incompatible in 1.3 that would make it hard
> to just bump the supported version?
1.2.1 requires a valid NQN in Identify Controller, and 1.3 requires
the new Identify CNS 03h for controller identification. Otherwise
it's mostly fine tuning corner conditions for which I'd have to audit
the code.
prev parent reply other threads:[~2017-05-05 10:10 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-05 9:00 [Qemu-devel] [PATCH] nvme: Implement Write Zeroes Christoph Hellwig
2017-05-05 9:30 ` Paolo Bonzini
2017-05-05 9:51 ` Christoph Hellwig
2017-05-05 10:03 ` Paolo Bonzini
2017-05-05 10:10 ` 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=20170505101026.GA7095@lst.de \
--to=hch@lst.de \
--cc=keith.busch@intel.com \
--cc=kwolf@redhat.com \
--cc=mreitz@redhat.com \
--cc=pbonzini@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).