Re: [PATCH 00/12] svcrdma: Fast memory registration support

["J. Bruce Fields" <bfields@fieldses.org>]

On Fri, Oct 03, 2008 at 04:33:37PM -0500, Tom Tucker wrote:
> 
> Bruce:
> 
> This updated patchset implements support for Fast Memory Registration
> in the NFS server. The second to last patch has been updated to
> provide better guidance on whether the connection is safe or
> not. Basically the code gives you a qualification string instead of
> expecting the administrator to know how to interpret the memory
> registration strategy and transport idiosyncrasies. The documentation
> has also been updated given your suggestions and the change to the
> informative log message. The string is certainly informative, but may
> be a little long. For this reason, there is a proc file entry to
> disable it.

OK, thanks, I've applied the first 10 patches (actually, merged them
from the for-bfields branch of your git tree).

I'm still a little iffy on patch #11.

--b.

> 
> Fast Memory Regstration is the ability to quickly map a kernel memory
> page list as a logically contiguous memory region from the perspective
> of the adapter. This mapping is created and invalidated using work
> requests posted on the SQ.
> 
> There are two benefits of this new memory registration strategy:
> 
> - It allows for large amounts of data to be transferred between the
>   client and server with a single work request
> 
> - It improves security since the effective lifetime and scope of an
>   RKEY is a single RPC and WR.
> 
> The documentation file Documentation/filesystems/nfs-rdma.txt file has
> been updated with information about NFSRDMA security in general and
> how it is affected by the new Fast Memory Registration capability.
> 
> This new capability is only enabled if the underlying device advertises
> that it is supported. It is not necessary that both the client and
> server use the same strategy, however, for Fast Memory Registration,
> it improves performance.
> 
> These patches are also available here:
> git://git.linux-nfs.org/projects/tomtucker/xprt-switch-2.6.git
> 
> Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
> 
> 
> [PATCH 01/12] svcrdma: Add Fast Reg MR Data Types
> 
>  include/linux/sunrpc/svc_rdma.h |   22 +++++++++++++++++++++-
>  1 files changed, 21 insertions(+), 1 deletions(-)
> 
> [PATCH 02/12] svcrdma: Add FRMR get/put services
> 
>  include/linux/sunrpc/svc_rdma.h          |    3 +
>  net/sunrpc/xprtrdma/svc_rdma_transport.c |  122 ++++++++++++++++++++++++++++-
>  2 files changed, 120 insertions(+), 5 deletions(-)
> 
> [PATCH 03/12] svcrdma: Query device for Fast Reg support during connection setup
> 
>  net/sunrpc/xprtrdma/svc_rdma_transport.c |   76 +++++++++++++++++++++++++++--
>  1 files changed, 70 insertions(+), 6 deletions(-)
> 
> [PATCH 04/12] svcrdma: Add a service to register a Fast Reg MR with the device
> 
>  include/linux/sunrpc/svc_rdma.h          |    1 +
>  net/sunrpc/xprtrdma/svc_rdma_transport.c |  118 +++++++++++++++++++++---------
>  2 files changed, 84 insertions(+), 35 deletions(-)
> 
> [PATCH 05/12] svcrdma: Modify post recv path to use local dma key
> 
>  net/sunrpc/xprtrdma/svc_rdma_transport.c |   12 +++++++++---
>  1 files changed, 9 insertions(+), 3 deletions(-)
> 
> [PATCH 06/12] svcrdma: Add support to svc_rdma_send to handle chained WR
> 
>  net/sunrpc/xprtrdma/svc_rdma_transport.c |   29 +++++++++++++++++++++--------
>  1 files changed, 21 insertions(+), 8 deletions(-)
> 
> [PATCH 07/12] svcrdma: Modify the RPC recv path to use FRMR when available
> 
>  include/linux/sunrpc/svc_rdma.h          |    1 +
>  net/sunrpc/xprtrdma/svc_rdma_recvfrom.c  |  187 ++++++++++++++++++++++++++----
>  net/sunrpc/xprtrdma/svc_rdma_transport.c |    5 +-
>  3 files changed, 171 insertions(+), 22 deletions(-)
> 
> [PATCH 08/12] svcrdma: Modify the RPC reply path to use FRMR when available
> 
>  net/sunrpc/xprtrdma/svc_rdma_sendto.c    |  263 +++++++++++++++++++++++++-----
>  net/sunrpc/xprtrdma/svc_rdma_transport.c |    2 +
>  2 files changed, 225 insertions(+), 40 deletions(-)
> 
> [PATCH 09/12] svcrdma: Update svc_rdma_send_error to use DMA LKEY
> 
>  net/sunrpc/xprtrdma/svc_rdma_transport.c |   11 +++++++++--
>  1 files changed, 9 insertions(+), 2 deletions(-)
> 
> [PATCH 10/12] svcrdma: Fix IRD/ORD polarity
> 
>  net/sunrpc/xprtrdma/svc_rdma_transport.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> [PATCH 11/12] svcrdma: Add a message log string to indicate if FastReg is being used
> 
>  include/linux/sunrpc/svc_rdma.h          |    1 +
>  net/sunrpc/xprtrdma/svc_rdma.c           |    8 ++++
>  net/sunrpc/xprtrdma/svc_rdma_transport.c |   63 ++++++++++++++++++-----------
>  3 files changed, 48 insertions(+), 24 deletions(-)
> 
> [PATCH 12/12] svcrdma: Documentation update for the FastReg memory model
> 
>  Documentation/filesystems/nfs-rdma.txt |  126 ++++++++++++++++++++++++++++++++
>  1 files changed, 126 insertions(+), 0 deletions(-)
>