[ofa-general] Re: mthca use of dma_sync_single is bogus
Michael S. Tsirkin
mst at dev.mellanox.co.il
Wed Jul 18 06:36:31 PDT 2007
> Quoting Roland Dreier <rdreier at cisco.com>:
> Subject: Re: [ofa-general] Re: mthca use of dma_sync_single is bogus
>
> > Hmm. This means there's no way to sync a range within
> > mapping created with map_sg?
>
> It doesn't seem that there is one right now at least.
>
> > > It actually doesn't look too bad to replace our use of pci_map_sg()
> > > with dma_map_single(), at least at first glance. I'll try to write a
> > > patch later.
> >
> > Well, the reason map_sg is there is presumably because on some
> > architectures it's worth it to try and make the region contigious in DMA space.
> > But I agree this seems the lesser evil at this point ...
>
> Given that we're already trying to allocate big chunks of physically
> contiguous memory, I think that any virtual merging we get is likely
> to be of very small benefit.
>
> It is kind of a shame to give this up though.
Did we reach any conclusion? Are you switching to map_single?
--
MST
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