From: Avi Kivity <avi@redhat.com>
To: Yonit Halperin <yhalperi@redhat.com>,
qemu-devel@nongnu.org, spice-devel@freedesktop.org,
Dave Airlie <airlied@redhat.com>
Subject: Re: [Qemu-devel] [Spice-devel] viewing continuous guest virtual memory as continuous in qemu
Date: Mon, 03 Oct 2011 17:10:48 +0200 [thread overview]
Message-ID: <4E89D078.3010301@redhat.com> (raw)
In-Reply-To: <20111003083755.GC16798@bow>
On 10/03/2011 10:37 AM, Alon Levy wrote:
> >
> > Hi,
> > won't there be an overhead for rendering on a non continuous
> > surface? Will it be worthwhile comparing to not creating the
> > surface?
>
> If I use a scatter-gather list there is overhead of allocating and
> copying the surface whenever I want to synchronize. Minimally once
> to copy from guest to host, and another copy from host to guest
> for any update_area. (we can only copy the required area.
>
> If I use page remapping like remap_file_pages does, I don't think
> there is any overhead for rendering. There is overhead for doing
> the remap_file_pages calls, but they are minimal (or so the man page
> says). I should benchmark this.
It's not trivial; and kvm and smp magnify the cost. It shouldn't be
done as part of normal rendering (setup is okay).
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2011-10-03 15:11 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-02 13:24 [Qemu-devel] viewing continuous guest virtual memory as continuous in qemu Alon Levy
2011-10-02 14:31 ` [Qemu-devel] [Spice-devel] " Alon Levy
2011-10-02 17:12 ` Avi Kivity
2011-10-03 7:49 ` Alon Levy
2011-10-03 8:17 ` Yonit Halperin
2011-10-03 8:37 ` Alon Levy
2011-10-03 8:49 ` Alon Levy
2011-10-03 15:10 ` Avi Kivity [this message]
2011-10-11 11:28 ` Gerd Hoffmann
2011-10-11 12:21 ` Alon Levy
2011-10-11 13:20 ` Gerd Hoffmann
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