Re: [PATCH rdma-next] RDMA/irdma: Check MR contiguity before PBLE alloc

[Jason Gunthorpe <jgg@ziepe.ca>]

On Sat, Oct 10, 2026 at 07:48:32PM +0000, Jacob Moroni wrote:
> @@ -3487,6 +3442,8 @@ static struct irdma_mr *irdma_alloc_iwmr(struct ib_umem *region,
>  	pgsz_bitmap = (reg_type == IRDMA_MEMREG_TYPE_MEM) ?
>  		iwdev->rf->sc_dev.hw_attrs.page_size_cap : SZ_4K;
>  
> +	iwmr->is_contig = ib_umem_is_contiguous(region);
> +	/* Call best_pgsz after is_contiguous to restore correct umem->iova. */
>  	iwmr->page_size = ib_umem_find_best_pgsz(region, pgsz_bitmap, virt);
>  	if (unlikely(!iwmr->page_size)) {
>  		kfree(iwmr);
> @@ -3846,6 +3803,7 @@ static int irdma_rereg_mr_trans(struct irdma_mr *iwmr, u64 start, u64 len,
>  	iwmr->region = region;
>  	iwmr->ibmr.iova = virt;
>  	iwmr->ibmr.pd = pd;
> +	iwmr->is_contig = ib_umem_is_contiguous(region);
>  	iwmr->page_size = ib_umem_find_best_pgsz(region,
>  				iwdev->rf->sc_dev.hw_attrs.page_size_cap,
>  				virt);

You should not call ib_umem_find_best_pgsz() after
ib_umem_is_contiguous(), it is nonsense to compute a page_size once
the contiguous optimization is being used.

Once you decide to use contiguous the start dma address should go
straight into the MR structure and just avoid all the pbl stuff.

Jason