On Tue, Dec 10, 2024 4:31 AM Jason Gunthorpe wrote:
> On Wed, Oct 09, 2024 at 10:59:00AM +0900, Daisuke Matsuda wrote:
>
> > +static bool rxe_ib_invalidate_range(struct mmu_interval_notifier *mni,
> > + const struct mmu_notifier_range *range,
> > + unsigned long cur_seq)
> > +{
> > + struct ib_umem_odp *umem_odp =
> > + container_of(mni, struct ib_umem_odp, notifier);
> > + struct rxe_mr *mr = umem_odp->private;
> > + unsigned long start, end;
> > +
> > + if (!mmu_notifier_range_blockable(range))
> > + return false;
> > +
> > + mutex_lock(&umem_odp->umem_mutex);
> > + mmu_interval_set_seq(mni, cur_seq);
> > +
> > + start = max_t(u64, ib_umem_start(umem_odp), range->start);
> > + end = min_t(u64, ib_umem_end(umem_odp), range->end);
> > +
> > + rxe_mr_unset_xarray(mr, start, end);
> > +
> > + /* update umem_odp->dma_list */
> > + ib_umem_odp_unmap_dma_pages(umem_odp, start, end);
>
> This seems like a strange thing to do, rxe has the xarray so why does
> it use the odp->dma_list?
I tried to reuse existing rxe codes for RDMA operations, and that required
to update the xarray also for ODP cases. I think using pfn_list only is technically
feasible.
>
> I think what you want is to have rxe disable the odp->dma_list and use
> its xarray instead
>
> Or use the odp lists as-is and don't include the xarray?
As you pointed out in reply to the next patch, the current implementation introduces
redundant copying overhead. We cannot avoid that with xarray, so I would rather
use the odp lists only.
Regards,
Daisuke
>
> Jason
