[ofw] WSD Detail Sample Code

Tzachi Dar tzachid at mellanox.co.il
Thu Jan 27 07:06:23 PST 2011 

Can you try and change your program to work in C/C++? This is what we have tested so far.

Please note that the current implementation of sdp does not have zero copy support. On the other hand, when a modern machine has so many cores, reaching zero copy is not that important. WSD has zero copy support.

Thanks
Tzachi

From: lock.zhang at gmail.com [mailto:lock.zhang at gmail.com] On Behalf Of suo zhang
Sent: Thursday, January 27, 2011 3:19 PM
To: Tzachi Dar
Cc: ofw at lists.openfabrics.org; znhu
Subject: Re: [ofw] WSD Detail Sample Code

Hi Tzachi

Following is the question with our customer. Mr. Hu is our customer who is using WSD.



We’ve checked the .net IO Completion implementation, it still go through the WinSocket and use Overlapped to do the work. What we mentioned is that the performance is poor and it turns out using WinSocket still go through IP stack. So we are trying to find what is the proper way to using ZCopy with WSD/SDP.

Thanks

On Thu, Jan 27, 2011 at 12:40 AM, Tzachi Dar <tzachid at mellanox.co.il<mailto:tzachid at mellanox.co.il>> wrote:
Hi,

I don’t think that we have ever tried to run neither wsd nor sdp on .net framework code, so I don’t know if it will work or not.

In any case, wsd has performance counters that you can use to verify if the traffic is going through or not (under ib winsock direct).
So please open this performance counters, and see if your program is using it or not?

Thanks
Tzachi

From: lock.zhang at gmail.com<mailto:lock.zhang at gmail.com> [mailto:lock.zhang at gmail.com<mailto:lock.zhang at gmail.com>] On Behalf Of suo zhang
Sent: Wednesday, January 26, 2011 8:25 AM
To: Tzachi Dar
Cc: ofw at lists.openfabrics.org<mailto:ofw at lists.openfabrics.org>

Subject: Re: [ofw] WSD Detail Sample Code

Hi

If the point 2 is true, we DO did the test with the WinSocket based code (we use .Net Framework 4.0 and use IO Completion port to send/receive the data in async mode), what the problem mentioned is that:

1.      I run my testing code try to send large data set and the performance throught can’t reach 300MB/s;

2.      I run the SDPConnect.exe tool（It can be found in server installed in MLNX_VPI/IB/Tools folder） use Overlapped send and receive in both side of the testing machine, it reached 900+MB/s throughput performance result.

So it turns out that we must seek more information from documentation or SDK for how to write such WinSocket based App, otherwise we just use InfiniBand as a normal IP based LAN.


On Tue, Jan 25, 2011 at 5:26 PM, Tzachi Dar <tzachid at mellanox.co.il<mailto:tzachid at mellanox.co.il>> wrote:
Hi,

It seems from your question that there is some confusion:

There are two ways to work with IB:


1)      Use native ib program. This means that you have to write your code differently, in order for it to work. To see examples of such programs you can download our code from svn://openib.tc.cornell.edu/gen1/trunk<http://openib.tc.cornell.edu/gen1/trunk>. there are many examples there (trunk\tools\perftests\user\send_bw, or trunk\tests\perftest\send_bw). In general in windows there are many apis that one can use. I’m currently not explaining this thoroughly, because I believe that you want to go to option #2.

2)      Use one of WSD or SDP. With this approach you don’t have to change anything in your source code. In fact, you don’t actually need to have the source code at all. For example the sdpconnect program (source attached) is a native windows socket program. You can find more information about how to run your program with one of this in the Mellanox documentation. Please also read the limitations section, as both have their limitations.

By the way, when you write “SDPConnect.exe  showed great performance”, how did you run it (wsd? SDP?)?

Thanks
Tzachi

From: ofw-bounces at lists.openfabrics.org<mailto:ofw-bounces at lists.openfabrics.org> [mailto:ofw-bounces at lists.openfabrics.org<mailto:ofw-bounces at lists.openfabrics.org>] On Behalf Of suo zhang
Sent: Tuesday, January 25, 2011 10:13 AM
To: ofw at lists.openfabrics.org<mailto:ofw at lists.openfabrics.org>
Subject: Re: [ofw] WSD Detail Sample Code

Hi

Following is our question.

Thanks

Suo

----------------------------------------------------------------------------
--------------------------------------------



We already wrote a IOCP and WinSocket based communication program. The
testing upon Infiniband indicated that this program still go over the
IPOverIP and has the overhead of Windows IP stack.



We saw this PPT and want to know how our WinSocket based program can fully
utilize the capabilities of Inifniband RDMA and how to write code over WSD
to avoid the overhead of Windows IP stack.



We just need a sample code like the source code of tool
SDPConnect.exe(within the Mallanox driver tools folder) etc. It showed great
performance we can’t achieved by our WinSocket code.



We’ve got some progress improvement:

1.       By searching the source code in OpenFabric, it turns out that these
open source include some tools’ source code, like this c file attached;

2.       There was some code founded in such tool’s source code like:

while (ccnt < user_param->iters || rcnt < user_param->iters ) {

          while (scnt < user_param->iters && (scnt - ccnt) <
user_param->tx_depth / 2) {

                   ib_send_wr_t  *bad_wr;

                   tposted[scnt] = get_cycles();

                   ib_status = ib_post_send(qp, &ctx->wr, &bad_wr);

                   if (ib_status != IB_SUCCESS) {

                            fprintf(stderr, "Couldn't post send: scnt=%d
ib_status %d\n",

                                      scnt,ib_status);

                            return 1;

                   }

                   ++scnt;

                   PERF_DEBUG("scnt = %d \n",scnt);

          }



But no document just have to guess from the source code for what “qp”,
“ctx” means and how to use them. These “ib_” initiated APIs were
absolutely NOT WinSocket APIs. What we asked for is SDK or documents for how
to using such API and which Header files we should include and which lib
have to be linked. A sample project will be OK if no such document exists.




Thanks

Suo
2011/1/25 Smith, Stan <stan.smith at intel.com<mailto:stan.smith at intel.com>>
Please submit modified question to ofw at lists.openfabrics.org<mailto:ofw at lists.openfabrics.org>

Furthermore, please identify which sample code you are referring to in order that someone can respond to your question.

Which Windows OS and processor (x86,x64,ia64).

Generally speaking WSD (WinSock Direct) is not used directly but utilized by opening a socket(AF_INET) which beneath the socket layer that has a WSD provider enabled for the specific address family.
For winOFED 2.3 release, run ‘installsp –l’ to see WSD providers.
WSD in no longer enabled by default for svr2008* – see ‘installsp –I’

Stan.


From: Suo Zhang <zhangs at bjcarnation.com.cn<mailto:zhangs at bjcarnation.com.cn>>
Date: 2011/1/20
Subject: WSD Detail Sample Code
To: membership at openfabrics.org<mailto:membership at openfabrics.org>
Hi
When I use WSD in my project, I found the sample code is very difficult to use. Because the sample code is very simple.
I want to know where can I get a detail sample code for WSD. Because my application must use zero copy to get good performance.
Thanks
Best regards

张锁 Suo Zhang
Sales Engineer
北京石竹科技有限公司
Beijing Carnation Technologies Limited
Mobile +86-186-1175-6167
Tel：+8610-68587971-8029
Fax：+8610-68587975
Http://www.vme.cn<http://www.vme.cn/>





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