xprtrdma: Move credit update to RPC reply handler
authorChuck Lever <chuck.lever@oracle.com>
Wed, 21 Jan 2015 16:03:02 +0000 (11:03 -0500)
committerAnna Schumaker <Anna.Schumaker@Netapp.com>
Fri, 30 Jan 2015 15:47:48 +0000 (10:47 -0500)
commiteba8ff660b2d8b7fcd6669fcab2c025b59f66d26
tree7a9a00e875d14cad14e389998a0f3cfbdfc94b83
parent3eb358106660195948f4e95822039c5799fc41f8
xprtrdma: Move credit update to RPC reply handler

Reduce work in the receive CQ handler, which can be run at hardware
interrupt level, by moving the RPC/RDMA credit update logic to the
RPC reply handler.

This has some additional benefits: More header sanity checking is
done before trusting the incoming credit value, and the receive CQ
handler no longer touches the RPC/RDMA header (the CPU stalls while
waiting for the header contents to be brought into the cache).

This further extends work begun by commit e7ce710a8802 ("xprtrdma:
Avoid deadlock when credit window is reset").

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
net/sunrpc/xprtrdma/rpc_rdma.c
net/sunrpc/xprtrdma/verbs.c
net/sunrpc/xprtrdma/xprt_rdma.h