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[Qemu-devel] Re: Faster, generic IO/DMA model with vectored AIO?
From: |
Blue Swirl |
Subject: |
[Qemu-devel] Re: Faster, generic IO/DMA model with vectored AIO? |
Date: |
Sat, 27 Oct 2007 19:53:16 +0300 |
On 10/27/07, Blue Swirl <address@hidden> wrote:
> I changed Slirp output to use vectored IO to avoid the slowdown from
> memcpy (see the patch for the work in progress, gives a small
> performance improvement). But then I got the idea that using AIO would
> be nice at the outgoing end of the network IO processing. In fact,
> vectored AIO model could even be used for the generic DMA! The benefit
> is that no buffering or copying should be needed.
I made a sketch of the API, please have a look at the patch.
> Each stage would translate the IO list and callback as needed and only
> the final stage would perform the IO or memcpy. This would be used in
> each stage of the chain memory<->IOMMU<->device<->SLIRP<->host network
> device. Of course some kind of host support for vectored AIO for these
> devices is required. On target side, devices that can do
> scatter/gather DMA would benefit most.
Inside Qemu the vectors would use target physical addresses (struct
qemu_iovec), but at some point the addresses would change to host
pointers suitable for real AIO.
gdma_aiov.diff
Description: Text Data
- [Qemu-devel] Faster, generic IO/DMA model with vectored AIO?, Blue Swirl, 2007/10/27
- [Qemu-devel] Re: Faster, generic IO/DMA model with vectored AIO?,
Blue Swirl <=
- Re: [Qemu-devel] Faster, generic IO/DMA model with vectored AIO?, Paul Brook, 2007/10/27
- Re: [Qemu-devel] Faster, generic IO/DMA model with vectored AIO?, Blue Swirl, 2007/10/28
- Re: [Qemu-devel] Faster, generic IO/DMA model with vectored AIO?, Blue Swirl, 2007/10/28
- Re: [Qemu-devel] Faster, generic IO/DMA model with vectored AIO?, Jamie Lokier, 2007/10/28
- Re: [Qemu-devel] Faster, generic IO/DMA model with vectored AIO?, Blue Swirl, 2007/10/29
- Re: [Qemu-devel] Faster, generic IO/DMA model with vectored AIO?, Blue Swirl, 2007/10/30