From: Christoph Hellwig <hch@lst.de>
To: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Kinglong Mee <kinglongmee@gmail.com>,
"J. Bruce Fields" <bfields@redhat.com>,
"linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>,
Trond Myklebust <trond.myklebust@primarydata.com>,
Christoph Hellwig <hch@lst.de>
Subject: Re: nfsd: supports read buffer from multiples pages
Date: Tue, 2 Feb 2016 10:20:54 +0100 [thread overview]
Message-ID: <20160202092054.GA26701@lst.de> (raw)
In-Reply-To: <20160201183805.GB5499@fieldses.org>
On Mon, Feb 01, 2016 at 01:38:05PM -0500, J. Bruce Fields wrote:
> This is with the xfs block layout?
>
> Christoph, do we know anything about average or worst-case sizes for
> that layout update field?
The average is rather small and fits into a single page, the worst
case is basically unlimited:
(file size / block size) * sizeof(pnfs_block_extent)
by the protocol, and about half that for a non-stupid client as
it would merge consecutive blocks and only trigger something close
to the worst case for a "block allocated, block hole, block allocated, ..."
pattern.
next prev parent reply other threads:[~2016-02-02 9:20 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-31 12:50 nfsd: supports read buffer from multiples pages Kinglong Mee
2016-02-01 18:38 ` J. Bruce Fields
2016-02-01 18:48 ` J. Bruce Fields
2016-02-02 0:54 ` Kinglong Mee
2016-02-02 9:20 ` Christoph Hellwig [this message]
2016-02-02 14:29 ` J. Bruce Fields
2016-02-29 9:49 ` Christoph Hellwig
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