> I am not familiar with how psm may set CC parameters.  Perhaps someone from
> QLogic/Intel can speak up here?

Intel's Fabric Manager User guide provides a brief section about enabling and 
using CCA. It can be downloaded from www.intel.com/infiniband. If you cannot 
download it, please contact me or our customer support offline and we can get 
you the manual and additional information about using CCA with PSM.

Basically there are configuration parameters in the Fabric Manager (FM) config 
file and there are PSM environment variable settings which can be modified. 
Once CCA is enabled in the FM config file, the fabric will use CCA since PSM 
has it enabled by default. The default values of PSM environment variables for 
CCA should be sufficient for most applications since we have taken care to find 
the best combination of parameters. If it becomes necessary to tune 
performance, additional PSM debug logging can be enabled to facilitate analysis 
of PSM CCA events.

- Edward
- -
- 

> -----Original Message-----
> From: ewg-boun...@lists.openfabrics.org [mailto:ewg-
> boun...@lists.openfabrics.org] On Behalf Of Ira Weiny
> Sent: Wednesday, June 27, 2012 9:26 AM
> To: Michael Zhang
> Cc: ewg@lists.openfabrics.org
> Subject: Re: [ewg] Questions about CC in OFED
> 
> On Wed, 27 Jun 2012 11:41:03 +0800
> Michael Zhang <ziwen1...@gmail.com> wrote:
> 
> > Hi everybody,
> >
> >   I focus on the source code of  IB congestion control in OFED, such
> > as CCT related data structure and FECN/BECN process. But the only code
> > related to the congestion control mechanism is found in the module of
> > "infinipath-psm". As I know, psm works for MPI applications and
> > actually I haven't installed psm in our system. I have done experiment
> > through IPoIB and the congestion control still works that makes me confused.
> 
> I am not familiar with how psm may set CC parameters.  Perhaps someone from
> QLogic/Intel can speak up here?
> 
> >   Could someone tell me where is the CC-related source code located
> > besides "infinipath-psm"? Or some functions are realized in hardware
> > such as the movement of CCT Index when receives BECN message?
> >   Thank you for your help!
> 
> The latest version of infiniband-diags (1.6.0)[*] has 2 tools (ibccquery and
> ibccconfig) which will allow one to query and set the CC parameters.  As you 
> will
> note in the man page as well as the help output these tools are not to be used
> lightly.  You can cause instability in your fabric if you set things wrong.
> However, when used properly they work well.
> 
> In addition, Al Chu from LLNL has posted a patch to OpenSM which allows for
> the setting of CC parameters in OpenSM.  Feedback from this patch has been
> minimal but Alex Netes (maintainer of OpenSM) says he will review it soon.
> (http://www.spinics.net/lists/linux-rdma/msg11615.html)
> 
> Finally, if you are interested in the ongoing development of this and other
> features of Open Fabrics code you may want to sign up for the linux-rdma
> mailing list (linux-r...@vger.kernel.org or http://vger.kernel.org/vger-
> lists.html).
> 
> Ira
> 
> [*] git://beany.openfabrics.org/~iraweiny/infiniband-diags.git
> 
> >
> > Best,
> > Ziwen
> >
> > --
> > Ziwen(Michael) Zhang Ph.D candidate
> > College of Computer
> > National University of Defense Technology (NUDT) , P.R.China
> > Email: zi...@nudt.edu.cn ziwen1...@gmail.com
> 
> 
> --
> Ira Weiny
> Member of Technical Staff
> Lawrence Livermore National Lab
> 925-423-8008
> wei...@llnl.gov
> _______________________________________________
> ewg mailing list
> ewg@lists.openfabrics.org
> http://lists.openfabrics.org/cgi-bin/mailman/listinfo/ewg
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