> On Mar 6, 2018, at 5:07 PM, Chuck Lever <chuck.lever@xxxxxxxxxx> wrote:
>
>
>
>> On Mar 6, 2018, at 5:02 PM, Anna Schumaker <Anna.Schumaker@xxxxxxxxxx> wrote:
>>
>> 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.
>
> OK. This looks like write is impacted, but this test doesn't
> actually perform any reads on the wire. Try iozone with -I,
> maybe? That would show results for both read and write.
Hum.
Stock v4.16-rc4:
./test5: read and write
wrote 1048576 byte file 10 times in 0.2 seconds (350811642 bytes/sec)
read 1048576 byte file 10 times in 0.0 seconds (-2147483648 bytes/sec)
./test5 ok.
v4.16-rc4 with my full set of patches:
./test5: read and write
wrote 1048576 byte file 10 times in 0.2 seconds (354236681 bytes/sec)
read 1048576 byte file 10 times in 0.0 seconds (-2147483648 bytes/sec)
./test5 ok.
I don't see a regression here. Let me know how it goes!
>> 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()
>
> It wasn't added there, it was moved from xprt_alloc_slot. So,
> it's not new work per-RPC.
>
> Any additional information would be appreciated!
>
>
>> 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;
>>>
>
> --
> Chuck Lever
>
>
>
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--
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