Messages in this thread | | | Subject | Re: [PATCH 4/5] iommu: Separate IOVA rcache memories from iova_domain structure | From | John Garry <> | Date | Wed, 22 Dec 2021 11:53:11 +0000 |
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On 20/12/2021 13:57, Robin Murphy wrote: >> Do you have any thoughts on this patch? The decision is whether we >> stick with a single iova domain structure or support this super >> structure for iova domains which support the rcache. I did not try the >> former - it would be do-able but I am not sure on how it would look. > > TBH I feel inclined to take the simpler approach of just splitting the > rcache array to a separate allocation, making init_iova_rcaches() public > (with a proper return value), and tweaking put_iova_domain() to make > rcache cleanup conditional. A residual overhead of 3 extra pointers in > iova_domain doesn't seem like *too* much for non-DMA-API users to bear.
OK, fine. So I tried as you suggested and it looks ok to me.
I'll send something out at rc1.
> Unless you want to try generalising the rcache mechanism completely away > from IOVA API specifics, it doesn't seem like there's really enough to > justify the bother of having its own distinct abstraction layer.
Yeah, I don't see that as necessary.
However something which could be useful is to separate the magazine code out for other possible users.
Thanks! John
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