nvidia-query-resource-opengl queries the NVIDIA OpenGL driver to determine the OpenGL resource usage of an application. OpenGL applications may query their own resource usage using the GL_NV_query_resource extension, but the nvidia-query-resource-opengl tool allows users to perform resource queries externally, against unmodified OpenGL applications.

• A Windows, Linux, Solaris, or FreeBSD system with an NVIDIA GPU, running a version of the NVIDIA OpenGL driver supporting the GL_NV_query_resource extension. Support for this extension was introduced with the 387.xx driver release. Note: this tool operates on the released NV extension and replaces an earlier tool that operated on the experimental NVX version of the extension.*
• CMake 2.6 or later, and a suitable build system (e.g. Windows SDK and/or Microsoft Visual Studio on Windows; make and cc/gcc on Unix-like systems) that is supported by the CMake generators on the target platform. (Not needed when using precompiled executables on Windows.)

nvidia-query-resource-opengl uses CMake to support building on multiple platforms. In order to build nvidia-query-resource-opengl, you will need to first use the CMake graphical or command line interface to generate a build system that will work on your platform, then use the generated build system to build the project. For example, on a typical Unix-like system, the following commands run from within the top level directory of this source code repository will create a "build" directory and build within it:

mkdir build
cd build
cmake ..
make

On Windows, run nmake instead of make from the Visual Studio command line when using the nmake build system generator with the Windows SDK, or choose a Visual Studio solution generator to create a solution that can be built within Microsoft Visual Studio. Windows users may also download precompiled executable files for convenience.

A successful build will produce the following items:

• The resource query tool, 'nvidia-query-resource-opengl' (on Windows, the .exe file extension is appended to the executable name.)
• A static library, 'libnvidia-query-resource-opengl.a' on Unix-like systems, or 'nvidia-query-resource-opengl.lib' on Windows. This can be used together with the API defined in include/nvidia-query-resource-opengl.h to add OpenGL resource query functionality to your own monitoring tools.
• On Unix-like systems only, the 'libnvidia-query-resource-preload.so' DSO, which must be preloaded into any OpenGL applications that will be the target of resource queries. (See "Usage" section below for more details.)

You can query an application's OpenGL resource usage by executing the command:

nvidia-query-resource-opengl -p <pid>

• pid: the process ID of the target OpenGL application of the query

The tool reports a summary, per device, of allocated video memory, the total amount of memory in use by the the driver, and the total amount of allocated but unused memory.

In addition a more detailed per object memory usage is reported. The current set of reported object types includes: - SYSTEM RESERVED - driver allocated memory - TEXTURE - memory in use by 1D/2D/3D textures - RENDERBUFFER - render buffer memory - BUFFEROBJ_ARRAY - buffer object memory

Resource queries are handled asynchronously to the OpenGL applications being queried. Due to this, and other factors, including object migration between video and system memory, it is possible for subsequent queries to yield different results.

On Windows, nvidia-query-resource-opengl will communicate directly with any OpenGL application to perform resource queries; however, on Unix-like systems, the libnvidia-query-resource-preload.so DSO must be preloaded into the target application before a resource query can be performed. This is achieved by setting a relative or absolute path to the preload DSO in the LD_PRELOAD variable of the target application's environment, e.g.:

$ LD_PRELOAD=path/to/libnvidia-query-resource-opengl-preload.so app