tree 38ac5b7609a68e073e33a6c6c5c705bf558eaddb
parent 346aa66b2ab7988ca105f7fee5a968c11712b0d8
author Chuck Lever <chuck.lever@oracle.com> 1432655536 -0400
committer Anna Schumaker <Anna.Schumaker@Netapp.com> 1434129036 -0400

xprtrdma: Acquire FMRs in rpcrdma_fmr_register_external()

Acquiring 64 FMRs in rpcrdma_buffer_get() while holding the buffer
pool lock is expensive, and unnecessary because FMR mode can
transfer up to a 1MB payload using just a single ib_fmr.

Instead, acquire ib_fmrs one-at-a-time as chunks are registered, and
return them to rb_mws immediately during deregistration.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Tested-By: Devesh Sharma <devesh.sharma@avagotech.com>
Reviewed-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>