Hi Chuck,
I'm seeing a huge performance hit with this patch. I'm just running cthon over TCP, and it goes from finishing in 22 seconds to taking well over 5 minutes. I seem to only see this on the read and write tests, such as basic test5 taking a minute to finish:
./test5: read and write
wrote 1048576 byte file 10 times in 60.35 seconds (173737 bytes/sec)
read 1048576 byte file 10 times in 0.0 seconds (-2147483648 bytes/sec)
./test5 ok.
I haven't dug into this too deeply, but my best guess is that maybe it's due to adding a call to xprt_request_init() in net/sunrpc/clnt.c:call_reserveresult()
Thoughts?
Anna
On 03/05/2018 03:13 PM, Chuck Lever wrote:
> alloc_slot is a transport-specific op, but initializing an rpc_rqst
> is common to all transports. Move initialization to common code in
> preparation for adding a transport-specific alloc_slot to xprtrdma.
>
> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
> ---
> include/linux/sunrpc/xprt.h | 1 +
> net/sunrpc/clnt.c | 1 +
> net/sunrpc/xprt.c | 12 +++++++-----
> 3 files changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
> index 5fea0fb..9784e28 100644
> --- a/include/linux/sunrpc/xprt.h
> +++ b/include/linux/sunrpc/xprt.h
> @@ -324,6 +324,7 @@ struct xprt_class {
> struct rpc_xprt *xprt_create_transport(struct xprt_create *args);
> void xprt_connect(struct rpc_task *task);
> void xprt_reserve(struct rpc_task *task);
> +void xprt_request_init(struct rpc_task *task);
> void xprt_retry_reserve(struct rpc_task *task);
> int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
> int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
> diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
> index 6e432ec..226f558 100644
> --- a/net/sunrpc/clnt.c
> +++ b/net/sunrpc/clnt.c
> @@ -1546,6 +1546,7 @@ void rpc_force_rebind(struct rpc_clnt *clnt)
> task->tk_status = 0;
> if (status >= 0) {
> if (task->tk_rqstp) {
> + xprt_request_init(task);
> task->tk_action = call_refresh;
> return;
> }
> diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
> index 70f0050..a394b46 100644
> --- a/net/sunrpc/xprt.c
> +++ b/net/sunrpc/xprt.c
> @@ -66,7 +66,7 @@
> * Local functions
> */
> static void xprt_init(struct rpc_xprt *xprt, struct net *net);
> -static void xprt_request_init(struct rpc_task *, struct rpc_xprt *);
> +static __be32 xprt_alloc_xid(struct rpc_xprt *xprt);
> static void xprt_connect_status(struct rpc_task *task);
> static int __xprt_get_cong(struct rpc_xprt *, struct rpc_task *);
> static void __xprt_put_cong(struct rpc_xprt *, struct rpc_rqst *);
> @@ -987,6 +987,8 @@ bool xprt_prepare_transmit(struct rpc_task *task)
> task->tk_status = -EAGAIN;
> goto out_unlock;
> }
> + if (likely(!bc_prealloc(req)))
> + req->rq_xid = xprt_alloc_xid(xprt);
> ret = true;
> out_unlock:
> spin_unlock_bh(&xprt->transport_lock);
> @@ -1163,10 +1165,10 @@ void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task)
> out_init_req:
> xprt->stat.max_slots = max_t(unsigned int, xprt->stat.max_slots,
> xprt->num_reqs);
> + spin_unlock(&xprt->reserve_lock);
> +
> task->tk_status = 0;
> task->tk_rqstp = req;
> - xprt_request_init(task, xprt);
> - spin_unlock(&xprt->reserve_lock);
> }
> EXPORT_SYMBOL_GPL(xprt_alloc_slot);
>
> @@ -1303,8 +1305,9 @@ static inline void xprt_init_xid(struct rpc_xprt *xprt)
> xprt->xid = prandom_u32();
> }
>
> -static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt)
> +void xprt_request_init(struct rpc_task *task)
> {
> + struct rpc_xprt *xprt = task->tk_xprt;
> struct rpc_rqst *req = task->tk_rqstp;
>
> INIT_LIST_HEAD(&req->rq_list);
> @@ -1312,7 +1315,6 @@ static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt)
> req->rq_task = task;
> req->rq_xprt = xprt;
> req->rq_buffer = NULL;
> - req->rq_xid = xprt_alloc_xid(xprt);
> req->rq_connect_cookie = xprt->connect_cookie - 1;
> req->rq_bytes_sent = 0;
> req->rq_snd_buf.len = 0;
>
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