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Date:   Thu, 6 Jun 2019 16:19:50 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Jason Gunthorpe <jgg@ziepe.ca>
Cc:     Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>,
        Sebastian Ott <sebott@linux.ibm.com>,
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Subject: Re: [PATCH 08/13] IB/iser: set virt_boundary_mask in the scsi host
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On Thu, Jun 06, 2019 at 09:59:35AM -0300, Jason Gunthorpe wrote:
> > Until we've sorted that out the device paramter needs to be set to
> > the smallest value supported.
> 
> smallest? largest? We've been setting it to the largest value the
> device can handle (ie 2G)

Well, in general we need the smallest value supported by any ULP,
because if any ULP can't support a larger segment size, we must not
allow the IOMMU to merge it to that size.  That being said I can't
really see why any RDMA ULP should limit the size given how the MRs
work.