[openib-general] [PATCHv2] mthca: speed up memory registration by filling MTTs directly

[Michael S. Tsirkin]

>  > > With current code firmware might be doing WRITE_MTT while CPU is writing to the
>  > > same cache line, and I expect this might confuse things, but it seems that with
>  > > my fmr/mr merge patch, we never have both CPU and firmware write to the same
>  > > MTTs entries.
>  > > 
>  > > So, assuming my patch is applied why isn't sticking pci_dma_sync_sg in FMR code
>  > > sufficient?
> 
> Yes, assuming that the CPU is the only entity ever writing to the MTT
> table, then doing pci_dma_sync_sg_for_cpu() before writing and
> pci_dma_sync_sg_for_device() afterwards should be OK.  I think.

However, for MPTs it seems the best we can do is allocate them
out of coherent memory.

-- 
MST