Changeset 92da231 in sasmodels

Timestamp:

Nov 24, 2015 4:45:03 PM (9 years ago)

Author:

Paul Kienzle <pkienzle@…>

Branches:

master, core_shell_microgels, costrafo411, magnetic_model, release_v0.94, release_v0.95, ticket-1257-vesicle-product, ticket_1156, ticket_1265_superball, ticket_822_more_unit_tests

Children:

5edfe12

Parents:

b514adf

Message:

add notes about compiler and opencl drivers to docs

Location:

sasmodels

Files:

• kernelcl.py (modified) (1 diff)
• kerneldll.py (modified) (2 diffs)

sasmodels/kernelcl.py

@@ -22 +22 @@
 devices, where it can be combined with other structure factors and form
 factors and have instrumental resolution effects applied.
+
+In order to use OpenCL for your models, you will need OpenCL drivers for
+your machine.  These should be available from your graphics card vendor.
+Intel provides OpenCL drivers for CPUs as well as their integrated HD
+graphics chipsets.  AMD also provides drivers for Intel CPUs, but as of
+this writing the performance is lacking compared to the Intel drivers.
+NVidia combines drivers for CUDA and OpenCL in one package.  The result
+is a bit messy if you have multiple drivers installed.  You can see which
+drivers are available by starting python and running:
+
+    import pyopencl as cl
+    cl.create_some_context(interactive=True)
+
+Once you have done that, it will show the available drivers which you
+can select.  It will then tell you that you can use these drivers
+automatically by setting the PYOPENCL_CTX environment variable.
+
+Some graphics cards have multiple devices on the same card.  You cannot
+yet use both of them concurrently to evaluate models, but you can run
+the program twice using a different device for each session.
+
+OpenCL kernels are compiled when needed by the device driver.  Some
+drivers produce compiler output even when there is no error.  You
+can see the output by setting PYOPENCL_COMPILER_OUTPUT=1.  It should be
+harmless, albeit annoying.
 """
 import os

sasmodels/kerneldll.py

@@ -1 @@
-"""
+r"""
 C types wrapper for sasview models.
 
@@ -5 +5 @@
 you wish to allow single precision floating point evaluation for the compiled
 models, otherwise it defaults to *False*.
+
+The compiler command line is stored in the attribute *COMPILE*, with string
+substitutions for %(source)s and %(output)s indicating what to compile and
+where to store it.  The actual command is system dependent.
+
+On windows systems, you have a choice of compilers.  *MinGW* is the GNU
+compiler toolchain, available in packages such as anaconda and PythonXY,
+or available stand alone. This toolchain has had difficulties on some
+systems, and may or may not work for you.  In order to build DLLs, *gcc*
+must be on your path.  If the environment variable *SAS_OPENMP* is given
+then -fopenmp is added to the compiler flags.  This requires a version
+of MinGW compiled with OpenMP support.
+
+An alternative toolchain uses the Microsoft Visual C++ compiler, available
+free from microsoft:
+
+    `http://www.microsoft.com/en-us/download/details.aspx?id=44266`_
+
+Again, this requires that the compiler is available on your path.  This is
+done by running vcvarsall.bat in a windows terminal.  Install locations are
+system dependent, such as:
+
+    C:\Program Files (x86)\Common Files\Microsoft\Visual C++ for Python\9.0\vcvarsall.bat
+
+or maybe
+
+    C:\Users\yourname\AppData\Local\Programs\Common\Microsoft\Visual C++ for Python\9.0\vcvarsall.bat
+
+And again, the environment variable *SAS_OPENMP* controls whether OpenMP is
+used to compile the C code.  This requires the Microsoft vcomp90.dll library,
+which doesn't seem to be included with the compiler, nor does there appear
+to be a public download location.  There may be one on your machine already
+in a location such as:
+
+    C:\Windows\winsxs\x86_microsoft.vc90.openmp*\vcomp90.dll
+
+If you copy this onto your path, such as the python directory or the install
+directory for this application, then OpenMP should be supported.
 """