Archive for the ‘CUDA.NET’ Category

00 – Preface

Tuesday, August 3rd, 2010

The new CUDA.NET Tutorials category was created to collect and manage resources and materials for developers starting to work and develop with CUDA.NET library for various platforms.

The usual composition will be of articles on specific topics and gradually increasing complexity.

This post will include an additional Table of Contents for published articles as we go.

Table of Contents

  1. Preface

 

For any question or comment, please contact us through our email address: support (at) hoopoe-cloud.com.

CUDA.NET 3.0.0 Released

Monday, June 21st, 2010

Dear all,

We are happy to announce the release of CUDA.NET version 3.0.0.
This release provides support for latest CUDA 3.0 API and few more updates that will make programming with CUDA from .NET easier and faster.

Additions:

  • Support for CUDA 3.0 API
  • Added memset functions for CUDA class
  • Supporting new graphics interoperability functions
  • Improved generics support for memory operations
  • Added CUDAContextSynchronizer class

Improved memory operations
We employ GCHandle class to be used with generic memory copies in CUDA class. This method allows to work with every data type (existing vectors or user defined) natively in .NET. The implication is that now you can copy existing custom arrays of structures/classes (user data-types) to device with memory copy functions.

CUDAContextSynchronizer
This class was added to assist developers in multi-GPU and multi-threaded environments sharing the same device. It uses existing CUDA API to manipulate the context each thread is attached to and provides .NET means to synchronize between threads sharing the same device for different computations.
Find it under the Tools namespace, the documentation includes a description of how to use it.

We hope you will enjoy this release.
As always, please send us comments or suggestions to: support@hoopoe-cloud.com.

GECCO 2010 – GPU Competition

Friday, January 15th, 2010

Dear all,

GECCO (GPUs for Genetic and Evolutionary Computation Conference) will take part this year between July 7th-11th, at Portland, Oregon, USA.

Rules and competition guidelines are published on the website provided by the link below.
Registration is open until June 4th, 2010.

Link to the competition GECCO 2010.

Thanks to Dr. Simon Harding, Memorial University, Canada, for the notes and update.

World Cloud Computing Summit 2009

Monday, November 30th, 2009

The 2nd annual cloud computing summit is about to take place in Shfayim, Israel, between December 2-3, 2009.

Following last year success, the event will cover recent developments and progress in cloud technologies. Presenting with top-of-the-line companies active in this field, including (partial list): Amazon, Google, eBay, IBM, HP, Sun, RedHat and more.

Additional “hands-on” labs and workshops are offered during the event for participants that would like to learn more about cloud technologies and integration possibilities.

We are also presenting Hoopoe at the summit, for GPU Cloud Computing, and providing a workshop on GPU Computing in general and Hoopoe as well.

This event ends 2009 and symbolically the last decade, marking cloud computing as a major development that we are about to see more and more in the next years.

You are invited to join us during the event.
Agenda
Registration

CIGPU 2010 – Computational Intelligence Session

Monday, November 30th, 2009

A special event is about to take place between 18-23 July, 2010 in Barcelona, Spain.

The session on Computational Intelligence on Consumer Games and Graphics Hardware (CIGPU 2010) will be part of IEEE World Congress on Computational Intelligence Conference 2010 (WCCI-2010).

Building on the success of previous CIGPU sessions and workshops, CIGPU 2010 will further explore the role that GPU technologies can play in computational intelligence (CI) research.  Submissions of original research are invited on the use of parallel graphics hardware for computational intelligence.  Work might involve exploring new techniques for exploiting the hardware, new algorithms to implement on the hardware, new applications for accelerated CI, new ways of making the technology available to CI researchers or the utilisation of the next generation of technologies.

“Anyone who has implemented computational intelligence techniques using any parallel graphics hardware will want to submit to this special session.”

Thanks to Dr. Simon Harding, Memorial University, Canada, for sharing this information with us.
In addition, the session will discuss using CUDA.NET for running related simulations on the GPU.

For more information: CIGPU 2010 Submissions

CUDA.NET 2.3.7 Released

Monday, October 26th, 2009

Dear all,

We would like to announce for the release of CUDA.NET 2.3.7.

This version addresses various issues with runtime API and types. The change was in data types and structures compliance with the native wrapper of CUDA Runtime API, to support cross-platform environments operating in 32 or 64 bit mode. The structures now support the SizeT structure we introduced in the previous CUDA.NET release.

Link to the download page.

Please send us your comments and feedback.

CUDA.NET examples issues

Thursday, September 24th, 2009

The examples attached with the CUDA.NET library demonstrate simple aspects of programming with CUDA.NET to the GPU.
They mostly consist of a code that runs on the GPU itself, written in the CUDA language. These files end with the *.cu suffix.

In order to use these files with the GPU, they have to pass a compilation step, processed by the nvcccompiler (included in CUDA Toolkit) to create a cubin file (binary file the GPU uses).
To operate properly, the nvcc compiler needs access to the cl compiler (Visual C++ equipped with Visual Studio or can be downloaded as standalone).

If nvcc cannot find the cl compiler or the environment is not fully configured it fails.
This can happen when cl is executed from a C# or VB.NET project (where the environment is not configured to C++).
To overcome the errors, it is possible to define to nvcc command line parameters that will allow it to compile the code. This parameter specifies the path to the cl compiler.
For example (considering a Visual Studio 2008 installation), add the following parameter:
–compiler-bindir=”C:\Program Files\Microsoft Visual Studio 9.0\VC\bin”

On different platforms/installations this path can be different. Older versions of Visual Studio will have a different path as well.
The complete command line to execute nvcc with is:
nvcc test.cu –cubin –compiler-bindir=”C:\Program Files\Microsoft Visual Studio 9.0\VC\bin”
If compiling a CUDA file named “test.cu”.

Problems with the CHM documentation

Thursday, September 24th, 2009

Hi,

We are being asked from time to time for errors when viewing the CHM documentation of CUDA.NET or OpenCL.NET.
Usually there is an “Internet Explorer” like message stating the page cannot be displayed.

This happens because of Internet Explorer security configuration that blocks CHM content when opened directly from the Web.
The best way to resolve it is to download the ZIP file to a safe folder on your computer (not temporary internet folders), unzip it and then open the file outside of Internet Explorer itself.

This should resolve the more in most of the cases.

SizeT – .NET and native code

Tuesday, September 15th, 2009

Hi,

In this post I wanted to introduce you with a new construct we added to the latest release of CUDA.NET (2.3.6) and will be available with the published OpenCL.NET library.

The problem

.NET is a very fixed environment, defining well known types, such that an int is always 4 bytes long (32 bit) and a long is always 8 bytes long (64 bit).

This is not the case with native code, for developers of C/C++. Writing a program in 32 bit environment, will always yield 32 bit types, unless using specific directives to get 64 bit variables. When writing 64 bit programs, they do get access to 64 bit wide variables as primitives supported by the compiler.

This clearly creates a portability problem for code and applications written in 32 and 64 bit environments.

Another example, is pointer size, where in C/C++ environments, under 32 bit the pointer is 4 bytes wide (int) and under 64 bit systems it is 8 bytes wide (long). The .NET environment (through different languages) provides a simple construct to overcome this problem, namely the IntPtr object, which some of you may be familiar with.

Now, coming back to our domain, the runtime API (also the driver in a new CUDA 2.3 function) and OpenCL makes extensive use of the C/C++ size_t data type. This data type ensures for developers that under different environments they will get the maximum width of the supported data type, unsigned int for 32 bit systems and unsigned long for 64 bit systems.

Possible options

By means of the interoprating library (wrapper), such as CUDA.NET, it creates a problem, since the API should provide several versions of the function, one given an uint (to map to 32 bit with unsigned int C/C++ type), and ulong (to map against unsigned long in 64 bit C/C++ systems). Supplying such an interface to the user will have to force him a specific behavior and system, since in .NET, the uint is always 32 bit wide, and ulong is 64 bit wide, no matter what.

Another option can be to provide a unique, standalone interface, using the IntPtr object, since .NET takes care to make it 32 bit wide in 32 bit systems and 64 bit wide for 64 bit systems, dynamically, without user intervention.

But using the IntPtr and a very serious downside, it is not dynamic, once it’s value is set, it cannot be changed through simple arithmetic operators, like +,-,*,/ or else.

The solution

Exactly for this purpose we created the SizeT object (structure). First, it maps to the same name as it’s native counterpart (size_t) and second it provides the dynamic mechanisms we want for working with 32 or 64 bit systems transparently.

SizeT can serve just like any other basic primitive in .NET.
For example:

SizeT temp = 15;
uint value = (uint)temp;
ulong value2 = (ulong)temp;
temp = value;

Internally, the SizeT wraps the IntPtr object to provide the same dynamic capabilities under 32 and 64 bit platforms.
It can host the required .NET primitives (int, uint, long, ulong), so when programming, one will make a good habit for using the SizeT instead of other data types (working with the runtime CUDA API).

For OpenCL the interface was built from the first place to use SizeT in mind, as the OpenCL API uses only size_t data types for cross platform functions.

Advanced data types with CUDA

Sunday, September 13th, 2009

Following with CUDA.NET 2.3.6 release, this article is meant to show you so of the more advanced constructs .NET can offer developers willing to get advanced interoperability with native code.
As most of you ar familiar, CUDA.NET offers to copy many types of arrays and data types to the GPU memory (through the different memcpy functions). These are based on well defined data types, mostly for numerical purposes.

Consider a basic data type of float, the corresponding array is declared as: float[], in C# or otherwise in different languages, but the principle is the same. In addition to these primitives (byte, short, int, long, float, double) there is also support for vector data types that CUDA support, such as Float2, where it is composed of 2 consequtive float elements.

What happens when you want to pass more complex data types that are not supported by CUDA.NET?

In this case, there are several techniques to achieve this goal, some maybe more complex to empploy than others, and it mostly depend on your expected usage.

1. Declaring a new copy function

Well, that’s always an option if you wish to extend the API of functions. In such case, the developer declares a new copy function to use, with expected parameters and consumes it.

The following example can show a little more:

// This is a dummy, complex data type
struct Test
{
public int value1;
public float value2;
}

// Define a new copy function to use with CUDA, assuming running under Linux
[DllImport("cuda")]
public static extern CUResult cuMemcpyHtoD(CUdeviceptr dst, Test[] src, uint bytes);

The definition above is for a function, to use, capable of copying data from an array of Test objects to device memory.
But, it may not always be convenient.

2. The dynamic, simpler way

Well, .NET offers one more possibility to convert .NET objects into native representation, without using “unsafe” mechanisms.

For this purpose, there is an object called “GCHandle” to use. This object provides an advanced control over the garbage collector of .NET to lock objects in memory and get their native pointer (IntPtr in .NET).

Since all copy functions in CUDA.NET support the IntPtr data type, one can use this mechanism as a generic way to copy data to the GPU. In practice, when a user calls one of the existing copy functions, the exact process is performed.

Again, consider the Test structure we created before.

// Getting native handle from an array
Test[] data = new Test[100];
// Fill in the array values...
GCHandle ptr = GCHandle.Alloc(data, GCHandleType.Pinned);
IntPtr src = ptr.AddrOfPinnedObject();
// Now copy to the GPU memory from this pointer...
....
// When finished, don't forget to free the GCHandle!
ptr.Free();

This is a simple process for exposing complex .NET data types to CUDA and CUDA.NET to be processed by the GPU.

In the next article we will present the new SizeT object we added for portability between 32 and 64 bit systems.