Thursday, December 23, 2010

GIT: Working on Branches: Sharing files and commits

You have several development branches but basically use the same files to test or benchmark all versions. Then there is no sense in developing different code in all these branches for the same purpose.
You can easily merge single files from one branch to the other by cherry-pick.

1. First commit a file and only the file you want to share, nothing else:
git commit -m"Newest fancy script which does all tests for all versions"
2. Save the key somewhere.
3. Go to the other branch folder or checkout the other branch in the same folder, as you like.
4. git cherry-pick 123784hash

You should now have the same file in the other branch as well.

Thanks to Markus for pointing me towards this.

Wednesday, December 22, 2010

GIT: Tagging

Tags are nothing else then names for certain revision.
So called annotated tags store the status of the project at a specific point in time for future use.

Create a tag:
git tag -a v1.0 -m"Your comment for version 1.0"

Push tag to repository:
git push --tags

Contact Information

Johannes Habich M. Sc.

* E-Mail: Johannes("at")
* Homepage:

Official RRZE contact site

Personal Homepage and private Contact

Monday, December 20, 2010

Windows7 / Vista / Server2008 unidentified network

Although a network consisting of a switch and 2 computers would be considered as very private, Win7(aso.) will consider it as unidentifiable and will not allow you to set the network to private.
Here's a howto on solving this issue:

1. Start –> run –> MMC –> press enter

2. In MMC console , from menu file select Add/Remove Snap-in

3. Select Group Policy Object editor –> Press Add –> select Local computer –> press OK –>press OK

4. Open Computer configration –>Windows Settings –>Security Settings –>select Network list manager policies
on the right Side you will see options:
double click –>Unidentified networks

5. Then you can select the option to consider the Unidentified networks as private and if user can change the


Friday, December 17, 2010

CUDA Windows Development Environment

Supported by the new NVIDIA Tesla Compute Cluster (TCC) driver we offer now an integrated development environment for CUDA on basis of Windows HPC2008 and Visual Studio.

For nearly 2 years now RRZE provides development resources for CUDA GPGPU computing under the Linux OS. In December 2009 a GPU cluster joined the two development machines in order to support production runs on up to 16 GPUs. Please contact us if you are interested in GPGPU computing, whether for Linux/Windows based development or production runs.

GIT: bookmark collection

Just some links:

Wednesday, December 15, 2010

GIT: Branching

To create a branch for some development work in git is really easy.
First clone an existing repository like described here.

In the new directory simple execute: git branch newbranch.
However, if you execute git status you will see that you are still on the master branch or the other branch you worked before (then the question is how did you get there
Execute git checkout newbranch an d git status will show you that you are now working on branch .
In order to push this information to another repository or a git server, git push per se will not do the trick. First you need to execute git push origin newbranch and now your branch is committed to the other repository.

Friday, December 10, 2010

Windows and CUDA; enabling TCC with nvidia-smi

Like in Linux you can use nvidia-smi to set different modes on the TESLA GPUs.
nvidia-smi is located usually at: C:\Program Files\NVIDIA Corporation\NVSMI\nvidia-smi.exe

Go there with a command prompt and administrative privileges and type nvidia-smi -s. This gives you the current status and the status of TCC mode after reboot.
Set exclusive compute mode enabled for the first GPU by nvidia-smi -g 0 -c 1
Set exclusive compute mode disabled for the first GPU by nvidia-smi -g 0 -c 0
For other GPUs increment the number after -g

/edit 24.12.2010:
Also look at the first comment on how to change between WDDM and TCC driver model.
Thanky Francoise for reporting my mistake. I corrected it above

Thursday, December 9, 2010

Win2008 HPC Server and CUDA TCC revisited

The release of the stable NVIDIA Driver 260.83 broke my Windows CUDA programming environment.
With the currently newst driver, 263.06, I gave it another shoot. Initially the CUDASDK sample programs did not recognize the GPU as CUDA capable and there was just some babbling about DRIVER and TK mismatch.
However this time searching the web got me to an IBM webpage which got a solution for their servers running Windows 2008 R2.
I tried this in Win2008 and it works like charm:

  • Enter the registry edit utility typing regedit in the run dialog and navigate to:


  • You will find subfolders named 0001 0002 aso. depending on the number of GPUs in your system.

  • For each card you want to enable CUDA go to that 000X directory and add the following reg key (32bit dword worked for me):


If you access the system via RDP read my blog entry on Using nvidia-smi for TCC on how to set this up!

Source of this information is IBM and can be found here for further reference and even more details: IBM Support Site