Re: Unexpected issues with 2 NVME initiators using the same target

[Jason Gunthorpe <jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>]

On Sun, Jul 02, 2017 at 02:17:52PM -0400, Chuck Lever wrote:

> I could kmalloc the SGE array instead, signal each Send,
> and then in the Send completion handler, unmap the SGEs
> and then kfree the SGE array. That's a lot of overhead.

Usually after allocating the send queue you'd pre-allocate all the
tracking memory needed for each SQE - eg enough information to do the
dma unmaps/etc?

> Or I could revert all the "map page cache pages" logic and
> just use memcpy for small NFS WRITEs, and RDMA the rest of
> the time. That keeps everything simple, but means large
> inline thresholds can't use send-in-place.

Don't you have the same problem with RDMA WRITE?

Jason
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