Mellanox Technologies
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                 MLNX_OFED for Linux GPUDirect Release Notes
			               Version 1.5.2-2.1.0-1.1.1000
  			                      May 2011
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Table of Contents
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1. Overview
2. Supported Platforms, Operating Systems and Firmware
3. GPU-Direct Features
4. Known Issues and Limitations


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1. Overview
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These are the release notes for Mellanox OFED GPUDirect, Rev 1.5.2 based on
MLNX_OFED_LINUX-1.5.2-2.1.0.
GPUDirect is a new technology from NVIDIA that enables faster communication
between the GPU and other devices on the PCIe bus, by removing the overhead due
to the CPU. Mellanox and NVIDIA GPUDirect solution enables memory sharing
between NVIDIAs' GPU and Mellanox HCA. This solution eliminates the need to 
copy data from one device to the other, thus minimizing the overhead 
of posting data computed by the GPU over the Infiniband network 
using Mellanox HCA.

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2. Supported Platforms, Operating Systems and Firmware
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1. Software:
  o Operating Systems:
    
    RHEL5.5 (MLNX_OFED_LINUX-GPUDIRECT-1.5.2-2.1.0-1.1.1000-rhel5.5.iso):
	- x86_64:
	- 2.6.18-194.nvel5
  o NVIDIA Development Driver for Linux x86_64 version 195.36.15 or later.
    Available on NVIDIA website at:
    http://developer.nvidia.com/object/gpucomputing.html

2. Hardware:
  o Mellanox ConnectX® HCA cards family
  o GPUDirect v1.0 supports deployment on Tesla M-class and Tesla S-class 
    datacenter products
    For further information on the supported GPUs, please contact NVIDIA.
                
3. Validated Firmware:
   Mellanox ConnectX®-2 (firmware fw-ConnectX2 Rev 2.8.0600 and above).

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3. GPUDirect Features
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This package is based on MLNX_OFED_LINUX-1.5.2-2.1.0 and includes the following
changes to support Mellanox GPUDirect capabilities:
1. Driver modifications to enable memory sharing between Mellanox ConnectX® HCA
   and NVIDIA GPU
2. docs/Nvidia_kernel directory contains patches provided by NVIDIA to enabele
   sharing of registered memory regions. 
3. Added environment variable IB_USE_GPU. This variable should be set
   whenever running an application that uses the GPUDirect feature.
   To set this variable run 'export IB_USE_GPU=1'.

For further information on MLNX_OFED v1.5.2-2.1.0 release, please refer to 
Mellanox OFED 1.5.2-2.1.0 Release Notes.

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4. Known Issues and Limitations
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1. MLNX_OFED_LINUX-GPUDIRECT-1.5.2-2.1.0-1.1.1000 can be used on kernels 
   patched with GPUDirect 1.0.2 patch only 
   (see under docs/Nvidia_kernel directory).
   Prepatched kernels can be downloaded from NVIDIA website:
   http://www.nvidia.com/
2. Mellanox OFED GPUDirect is tested only on hosts with Mellanox ConnectX® 
   device and a single active InfiniBand port.
3. GPUDirect capabilities cannot be used in applications that call functions
   such as fork() and madvise().