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Revert "SUNRPC: Micro-optimise when the task is known not to be sleeping"

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This reverts commit 009a82f643.

The ability to optimise here relies on compiler being able to optimise
away tail calls to avoid stack overflows. Unfortunately, we are seeing
reports of problems, so let's just revert.

Reported-by: Daniel Mack <daniel@zonque.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This commit is contained in:
Trond Myklebust 2019-04-11 15:16:52 -04:00
parent 0769663b4f
commit af6b61d7ef
2 changed files with 8 additions and 45 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
include/linux/sunrpc/sched.h
View File

@ -304,12 +304,4 @@ rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
}
#endif /* CONFIG_SUNRPC_SWAP */
static inline bool
rpc_task_need_resched(const struct rpc_task *task)
{
if (RPC_IS_QUEUED(task) || task->tk_callback)
return true;
return false;
}
#endif /* _LINUX_SUNRPC_SCHED_H_ */

45
net/sunrpc/clnt.c
View File

@ -1540,7 +1540,6 @@ call_start(struct rpc_task *task)
clnt->cl_stats->rpccnt++;
task->tk_action = call_reserve;
rpc_task_set_transport(task, clnt);
call_reserve(task);
}
/*
@ -1554,9 +1553,6 @@ call_reserve(struct rpc_task *task)
task->tk_status = 0;
task->tk_action = call_reserveresult;
xprt_reserve(task);
if (rpc_task_need_resched(task))
return;
call_reserveresult(task);
}
static void call_retry_reserve(struct rpc_task *task);
@ -1579,7 +1575,6 @@ call_reserveresult(struct rpc_task *task)
if (status >= 0) {
if (task->tk_rqstp) {
task->tk_action = call_refresh;
call_refresh(task);
return;
}
@ -1605,7 +1600,6 @@ call_reserveresult(struct rpc_task *task)
/* fall through */
case -EAGAIN: /* woken up; retry */
task->tk_action = call_retry_reserve;
call_retry_reserve(task);
return;
case -EIO: /* probably a shutdown */
break;
@ -1628,9 +1622,6 @@ call_retry_reserve(struct rpc_task *task)
task->tk_status = 0;
task->tk_action = call_reserveresult;
xprt_retry_reserve(task);
if (rpc_task_need_resched(task))
return;
call_reserveresult(task);
}
/*
@ -1645,9 +1636,6 @@ call_refresh(struct rpc_task *task)
task->tk_status = 0;
task->tk_client->cl_stats->rpcauthrefresh++;
rpcauth_refreshcred(task);
if (rpc_task_need_resched(task))
return;
call_refreshresult(task);
}
/*
@ -1666,7 +1654,6 @@ call_refreshresult(struct rpc_task *task)
case 0:
if (rpcauth_uptodatecred(task)) {
task->tk_action = call_allocate;
call_allocate(task);
return;
}
/* Use rate-limiting and a max number of retries if refresh
@ -1685,7 +1672,6 @@ call_refreshresult(struct rpc_task *task)
task->tk_cred_retry--;
dprintk("RPC: %5u %s: retry refresh creds\n",
task->tk_pid, __func__);
call_refresh(task);
return;
}
dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
@ -1711,10 +1697,8 @@ call_allocate(struct rpc_task *task)
task->tk_status = 0;
task->tk_action = call_encode;
if (req->rq_buffer) {
call_encode(task);
if (req->rq_buffer)
return;
}
if (proc->p_proc != 0) {
BUG_ON(proc->p_arglen == 0);
@ -1740,12 +1724,8 @@ call_allocate(struct rpc_task *task)
status = xprt->ops->buf_alloc(task);
xprt_inject_disconnect(xprt);
if (status == 0) {
if (rpc_task_need_resched(task))
return;
call_encode(task);
if (status == 0)
return;
}
if (status != -ENOMEM) {
rpc_exit(task, status);
return;
@ -1828,8 +1808,12 @@ call_encode(struct rpc_task *task)
xprt_request_enqueue_receive(task);
xprt_request_enqueue_transmit(task);
out:
task->tk_action = call_bind;
call_bind(task);
task->tk_action = call_transmit;
/* Check that the connection is OK */
if (!xprt_bound(task->tk_xprt))
task->tk_action = call_bind;
else if (!xprt_connected(task->tk_xprt))
task->tk_action = call_connect;
}
/*
@ -1847,7 +1831,6 @@ rpc_task_handle_transmitted(struct rpc_task *task)
{
xprt_end_transmit(task);
task->tk_action = call_transmit_status;
call_transmit_status(task);
}
/*
@ -1865,7 +1848,6 @@ call_bind(struct rpc_task *task)
if (xprt_bound(xprt)) {
task->tk_action = call_connect;
call_connect(task);
return;
}
@ -1896,7 +1878,6 @@ call_bind_status(struct rpc_task *task)
dprint_status(task);
task->tk_status = 0;
task->tk_action = call_connect;
call_connect(task);
return;
}
@ -1981,7 +1962,6 @@ call_connect(struct rpc_task *task)
if (xprt_connected(xprt)) {
task->tk_action = call_transmit;
call_transmit(task);
return;
}
@ -2051,7 +2031,6 @@ call_connect_status(struct rpc_task *task)
case 0:
clnt->cl_stats->netreconn++;
task->tk_action = call_transmit;
call_transmit(task);
return;
}
rpc_exit(task, status);
@ -2087,9 +2066,6 @@ call_transmit(struct rpc_task *task)
xprt_transmit(task);
}
xprt_end_transmit(task);
if (rpc_task_need_resched(task))
return;
call_transmit_status(task);
}
/*
@ -2107,9 +2083,6 @@ call_transmit_status(struct rpc_task *task)
if (rpc_task_transmitted(task)) {
if (task->tk_status == 0)
xprt_request_wait_receive(task);
if (rpc_task_need_resched(task))
return;
call_status(task);
return;
}
@ -2170,7 +2143,6 @@ call_bc_encode(struct rpc_task *task)
{
xprt_request_enqueue_transmit(task);
task->tk_action = call_bc_transmit;
call_bc_transmit(task);
}
/*
@ -2261,7 +2233,6 @@ call_status(struct rpc_task *task)
status = task->tk_status;
if (status >= 0) {
task->tk_action = call_decode;
call_decode(task);
return;
}