tree 56015ecbc381615db5c4370ad104f54a52cd17d2
parent 6b26cc8c8ead3636a18bfd9489984983f4ddd6f4
author Chuck Lever <chuck.lever@oracle.com> 1462214448 -0400
committer Anna Schumaker <Anna.Schumaker@Netapp.com> 1463514477 -0400

xprtrdma: Bound the inline threshold values

Currently the sysctls that allow setting the inline threshold allow
any value to be set.

Small values only make the transport run slower. The default 1KB
setting is as low as is reasonable. And the logic that decides how
to divide a Send buffer between RPC-over-RDMA header and RPC message
assumes (but does not check) that the lower bound is not crazy (say,
57 bytes).

Send and receive buffers share a page with some control information.
Values larger than about 3KB can't be supported, currently.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>