xprtrdma: Don't clear RPC_BC_PA_IN_USE on pre-allocated rpc_rqst's

No need for the overhead of atomically setting and clearing this bit
flag for every use of a pre-allocated backchannel rpc_rqst. These
are a distinct pool of rpc_rqsts that are used only for callback
operations, so it is safe to simply leave the bit set.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This commit is contained in:
Chuck Lever 2017-12-14 20:57:39 -05:00 committed by Anna Schumaker
parent cf73daf527
commit 30b5416bf0
1 changed files with 1 additions and 6 deletions

View File

@ -120,6 +120,7 @@ int xprt_rdma_bc_setup(struct rpc_xprt *xprt, unsigned int reqs)
rqst->rq_xprt = &r_xprt->rx_xprt;
INIT_LIST_HEAD(&rqst->rq_list);
INIT_LIST_HEAD(&rqst->rq_bc_list);
__set_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state);
if (rpcrdma_bc_setup_rqst(r_xprt, rqst))
goto out_free;
@ -284,11 +285,6 @@ void xprt_rdma_bc_free_rqst(struct rpc_rqst *rqst)
dprintk("RPC: %s: freeing rqst %p (req %p)\n",
__func__, rqst, rpcr_to_rdmar(rqst));
smp_mb__before_atomic();
WARN_ON_ONCE(!test_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state));
clear_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state);
smp_mb__after_atomic();
spin_lock_bh(&xprt->bc_pa_lock);
list_add_tail(&rqst->rq_bc_pa_list, &xprt->bc_pa_list);
spin_unlock_bh(&xprt->bc_pa_lock);
@ -343,7 +339,6 @@ void rpcrdma_bc_receive_call(struct rpcrdma_xprt *r_xprt,
rqst->rq_xid = *p;
rqst->rq_private_buf.len = size;
set_bit(RPC_BC_PA_IN_USE, &rqst->rq_bc_pa_state);
buf = &rqst->rq_rcv_buf;
memset(buf, 0, sizeof(*buf));