On Tue, Feb 12, 2008 at 07:54:48AM -0800, David Miller wrote: > > Something could be done: > > we could enable drivers to have DMA-pools they manage that get mapped > > and are re-used. > > > > I would rather the DMA-pools be tied to PID's that way any bad behavior > > would be limited to the address space of the process using the device. > > I haven't thought about how hard this would be to do but it would be > > nice. I think this could be tricky. > > Yes, this is a good idea especially for networking. > > For transmit on 10GB links the IOMMU setup is near the top > of the profiles.
true. > What a driver could do is determine the maximum number of > IOMMU pages it could need to map one maximally sized packet. > So then it allocates enough space for all such entries in > it's TX ring. > > This eliminates the range allocation from the transmit path. > All that's left is "remap DMA range X to scatterlist Y" > > And yes it would be nice to have dma_map_skb() type interfaces > so that we don't walk into the IOMMU code N times per packet. /me starts looking more closely at how this could be done... --mgross -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/