From: Rusty Russell <rusty@rustcorp.com.au>
To: Anthony Liguori <aliguori@us.ibm.com>
Cc: Mark McLoughlin <markmc@redhat.com>,
Avi Kivity <avi@qumranet.com>,
kvm@vger.kernel.org
Subject: Re: [PATCH 4/5] kvm: qemu: Use vringfd to eliminate copies
Date: Mon, 16 Jun 2008 12:10:57 +1000 [thread overview]
Message-ID: <200806161210.57926.rusty@rustcorp.com.au> (raw)
In-Reply-To: <48545422.1040109@us.ibm.com>
On Sunday 15 June 2008 09:28:34 Anthony Liguori wrote:
> Have you benchmarked the driver? I wasn't seeing great performance
> myself although I think that was due to some bugs in the vringfd code.
Yeah, every time I get close to benchmarking I find another bug :( But I've
spent some time optimising the normal lguest net device, so we'll have a fair
comparison.
In theory vringfd will get us zero copy from guest sendfile out to external
machines. For anything else we're doing a copy anyway, so avoiding copying
has no great benefit.
The interface is still worthwhile to provide zero-copy receive on intelligent
or bound NICs, but that's science fiction at the moment...
Cheers,
Rusty.
next prev parent reply other threads:[~2008-06-16 3:14 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-13 13:57 [PATCH 0/0][RFC] KVM use of vringfd Mark McLoughlin
2008-06-13 13:57 ` [PATCH 1/5] vring: Replace mmap() interface with ioctl() Mark McLoughlin
2008-06-13 13:57 ` [PATCH 2/5] lguest: Use VRINGSETINFO ioctl() instead of mmap() Mark McLoughlin
2008-06-13 13:57 ` [PATCH 3/5] kvm: qemu: Publish last_avail index in the ring Mark McLoughlin
2008-06-13 13:58 ` [PATCH 4/5] kvm: qemu: Use vringfd to eliminate copies Mark McLoughlin
2008-06-13 13:58 ` [PATCH 5/5] kvm: qemu: Add support for partial csums and GSO Mark McLoughlin
2008-06-14 23:28 ` [PATCH 4/5] kvm: qemu: Use vringfd to eliminate copies Anthony Liguori
2008-06-16 2:10 ` Rusty Russell [this message]
2008-06-16 14:02 ` Anthony Liguori
2008-06-16 14:58 ` Avi Kivity
2008-06-18 5:43 ` Rusty Russell
2008-06-18 14:01 ` Avi Kivity
2008-06-17 14:08 ` Mark McLoughlin
2008-06-17 14:54 ` Anthony Liguori
2008-06-17 15:45 ` Mark McLoughlin
2008-06-13 14:09 ` [PATCH 1/5] vring: Replace mmap() interface with ioctl() Avi Kivity
2008-06-17 12:19 ` Mark McLoughlin
2008-06-18 14:05 ` Avi Kivity
2008-06-14 9:02 ` Rusty Russell
2008-06-14 14:20 ` Avi Kivity
2008-06-14 23:23 ` Anthony Liguori
2008-06-15 15:24 ` Avi Kivity
2008-06-15 19:13 ` Anthony Liguori
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