Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:29851 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752477AbdHPQnM (ORCPT ); Wed, 16 Aug 2017 12:43:12 -0400 Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) Subject: Re: [PATCH v2 5/6] SUNRPC: Add a function to allow waiting for RPC transmission From: Chuck Lever In-Reply-To: <20170816161929.11271-6-trond.myklebust@primarydata.com> Date: Wed, 16 Aug 2017 12:43:07 -0400 Cc: Linux NFS Mailing List Message-Id: References: <20170816161929.11271-1-trond.myklebust@primarydata.com> <20170816161929.11271-2-trond.myklebust@primarydata.com> <20170816161929.11271-3-trond.myklebust@primarydata.com> <20170816161929.11271-4-trond.myklebust@primarydata.com> <20170816161929.11271-5-trond.myklebust@primarydata.com> <20170816161929.11271-6-trond.myklebust@primarydata.com> To: Trond Myklebust Sender: linux-nfs-owner@vger.kernel.org List-ID: > On Aug 16, 2017, at 12:19 PM, Trond Myklebust wrote: > > Sometimes, we only want to know that the RPC message is in the process > of being transmitted. Add a function to allow that. The last time I tried these last two, they resulted in a significant performance regression. Is there anything I can do to help track that down? > Signed-off-by: Trond Myklebust > --- > include/linux/sunrpc/sched.h | 3 +++ > net/sunrpc/sched.c | 22 ++++++++++++++++++++++ > net/sunrpc/xprt.c | 6 ++++++ > 3 files changed, 31 insertions(+) > > diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h > index c1768f9d993b..148cd6c5d2eb 100644 > --- a/include/linux/sunrpc/sched.h > +++ b/include/linux/sunrpc/sched.h > @@ -141,6 +141,8 @@ struct rpc_task_setup { > #define RPC_TASK_ACTIVE 2 > #define RPC_TASK_MSG_RECV 3 > #define RPC_TASK_MSG_RECV_WAIT 4 > +#define RPC_TASK_MSG_XMIT 5 > +#define RPC_TASK_MSG_XMIT_WAIT 6 > > #define RPC_IS_RUNNING(t) test_bit(RPC_TASK_RUNNING, &(t)->tk_runstate) > #define rpc_set_running(t) set_bit(RPC_TASK_RUNNING, &(t)->tk_runstate) > @@ -246,6 +248,7 @@ void rpc_free(struct rpc_task *); > int rpciod_up(void); > void rpciod_down(void); > int __rpc_wait_for_completion_task(struct rpc_task *task, wait_bit_action_f *); > +int rpc_wait_for_msg_send(struct rpc_task *task); > #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) > struct net; > void rpc_show_tasks(struct net *); > diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c > index 0cc83839c13c..30509a4d7e00 100644 > --- a/net/sunrpc/sched.c > +++ b/net/sunrpc/sched.c > @@ -320,6 +320,19 @@ int __rpc_wait_for_completion_task(struct rpc_task *task, wait_bit_action_f *act > EXPORT_SYMBOL_GPL(__rpc_wait_for_completion_task); > > /* > + * Allow callers to wait for completion of an RPC call > + */ > +int rpc_wait_for_msg_send(struct rpc_task *task) > +{ > + if (!test_bit(RPC_TASK_MSG_XMIT, &task->tk_runstate)) > + return 0; > + set_bit(RPC_TASK_MSG_XMIT_WAIT, &task->tk_runstate); > + return wait_on_bit_action(&task->tk_runstate, RPC_TASK_MSG_XMIT, > + rpc_wait_bit_killable, TASK_KILLABLE); > +} > +EXPORT_SYMBOL_GPL(rpc_wait_for_msg_send); > + > +/* > * Make an RPC task runnable. > * > * Note: If the task is ASYNC, and is being made runnable after sitting on an > @@ -700,6 +713,7 @@ rpc_reset_task_statistics(struct rpc_task *task) > { > task->tk_timeouts = 0; > task->tk_flags &= ~(RPC_CALL_MAJORSEEN|RPC_TASK_KILLED|RPC_TASK_SENT); > + set_bit(RPC_TASK_MSG_XMIT, &task->tk_runstate); > > rpc_init_task_statistics(task); > } > @@ -928,6 +942,7 @@ static void rpc_init_task(struct rpc_task *task, const struct rpc_task_setup *ta > memset(task, 0, sizeof(*task)); > atomic_set(&task->tk_count, 1); > task->tk_flags = task_setup_data->flags; > + task->tk_runstate = BIT(RPC_TASK_MSG_XMIT); > task->tk_ops = task_setup_data->callback_ops; > task->tk_calldata = task_setup_data->callback_data; > INIT_LIST_HEAD(&task->tk_task); > @@ -1012,6 +1027,13 @@ static void rpc_async_release(struct work_struct *work) > > static void rpc_release_resources_task(struct rpc_task *task) > { > + if (test_bit(RPC_TASK_MSG_XMIT, &task->tk_runstate)) { > + clear_bit(RPC_TASK_MSG_XMIT, &task->tk_runstate); > + smp_mb__after_atomic(); > + if (test_bit(RPC_TASK_MSG_XMIT_WAIT, &task->tk_runstate)) > + wake_up_bit(&task->tk_runstate, RPC_TASK_MSG_XMIT); > + } > + > xprt_release(task); > if (task->tk_msg.rpc_cred) { > put_rpccred(task->tk_msg.rpc_cred); > diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c > index a558e8c620c0..62c379865f7c 100644 > --- a/net/sunrpc/xprt.c > +++ b/net/sunrpc/xprt.c > @@ -978,6 +978,12 @@ bool xprt_prepare_transmit(struct rpc_task *task) > goto out_unlock; > } > ret = true; > + if (test_bit(RPC_TASK_MSG_XMIT, &task->tk_runstate)) { > + clear_bit(RPC_TASK_MSG_XMIT, &task->tk_runstate); > + smp_mb__after_atomic(); > + if (test_bit(RPC_TASK_MSG_XMIT_WAIT, &task->tk_runstate)) > + wake_up_bit(&task->tk_runstate, RPC_TASK_MSG_XMIT); > + } > out_unlock: > spin_unlock_bh(&xprt->transport_lock); > return ret; > -- > 2.13.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Chuck Lever