Re: [RFC PATCH 1/2] swiotlb: Split up single swiotlb lock

[Andi Kleen]

On 4/28/2022 7:45 AM, Christoph Hellwig wrote:
> On Thu, Apr 28, 2022 at 03:44:36PM +0100, Robin Murphy wrote:
> > Rather than introduce this extra level of allocator complexity, how about
> > just dividing up the initial SWIOTLB allocation into multiple io_tlb_mem
> > instances?
> Yeah.  We're almost done removing all knowledge of swiotlb from drivers,
> so the very last thing I want is an interface that allows a driver to
> allocate a per-device buffer.

At least for TDX need parallelism with a single device for performance.

So if you split up the io tlb mems for a device then you would need a 
new mechanism to load balance the requests for single device over those. 
I doubt it would be any simpler.


-Andi