Re: [PATCH v9 0/6] MAP_DIRECT for DAX userspace flush

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, Oct 16, 2017 at 12:44:31PM -0700, Dan Williams wrote:
> > While I agree with the need for a per-MR notification mechanism, one
> > thing we lose by walking away from MAP_DIRECT is a way for a
> > hypervisor to coordinate pass through of a DAX mapping to an RDMA
> > device in a guest. That will remain a case where we will still need to
> > use device-dax. I'm fine if that's the answer, but just want to be
> > clear about all the places we need to protect a DAX mapping against
> > RDMA from a non-ODP device.
> 
> For this specific issue perhaps we promote FL_LAYOUT as a lease-type
> that can be set by fcntl().

I don't think it is a good userspace interface, mostly because it
is about things that don't matter for userspace (block mappings).

It makes sense as a kernel interface for callers that want to pin
down a memory long-term, but for userspace the fact that the block
mapping changes doesn't matter - it matters that their long term
pin is broken by something.
--
To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [XFS Filesystem Development (older mail)]     [Linux Filesystem Development]     [Linux Audio Users]     [Yosemite Trails]     [Linux Kernel]     [Linux RAID]     [Linux SCSI]


  Powered by Linux