Hi, > After poking around with different headers it appears I need one of the > object type files such as "viennacl/matrix.hpp" in order to declare > viennacl::context objects. Shouldn't this be possible from just > "viennacl/ocl/backend.hpp"? Just curious on the design at this point.
have you tried to include viennacl/context.hpp directly? Best regards, Karli > On Tue, May 10, 2016 at 8:40 AM, Charles Determan <cdeterma...@gmail.com > <mailto:cdeterma...@gmail.com>> wrote: > > Excellent, thank you for explaining that. One followup thing, I am > trying a trivial function to test this: > > int findContext(int x){ > viennacl::context > ctx(viennacl::ocl::get_context(static_cast<long>(x))) > return x > } > > but I keep getting a compiler error: > > >error: variable ‘viennacl::context ctx’ has initializer but > incomplete type > > Did I miss something? > > Thanks, > Charles > > > On Mon, May 9, 2016 at 4:09 PM, Karl Rupp <r...@iue.tuwien.ac.at > <mailto:r...@iue.tuwien.ac.at>> wrote: > > Hi Charles, > > setContext() is not thread-safe, so if mclapply() is executing > in parallel, there will be a race. MPI works across processes, > so globals are not shared (and hence setContext() has no problems). > > If you want to run multithreaded, you should manage the contexts > explicitly. That is, pass a viennacl::context object to the > respective constructors of viennacl::vector, viennacl::matrix, > etc. You can find examples here: > > https://github.com/viennacl/viennacl-dev/blob/master/examples/tutorial/multithreaded.cpp > > https://github.com/viennacl/viennacl-dev/blob/master/examples/tutorial/multithreaded_cg.cpp > > Best regards, > Karli > > > > > On 05/09/2016 10:32 PM, Charles Determan wrote: > > I am trying to use multiple GPU's in parallel using ViennaCL > through my > gpuR package. In essence the context is selected at the R > level (one > context per device already initialized). Then a matrix is > created on > that device. The code looks like this: > > create_matrix <- function(id){ > # sets context > setContext(id) > # create matrix > mat <- vclMatrix(rnorm(16), nrow=4, ncol=4) > return(mat) > } > > # a fork over context 1 and 2 > out <- mclapply(1:2, function(x) create_matrix(x)) > > Yet, strangely this just hangs. It doesn't return > anything. Perhaps I > am missing something in how OpenCL contexts are handed in > parallel? I > ask as I recall that PETSC had some multi GPU functionality > with MPI. > The above makes sense to me without MPI but again I may be > missing > something. > > The actual copying happens in this file at line 36 > (https://github.com/cdeterman/gpuR/blob/develop/src/dynVCLMat.cpp) > just > after "starting to copy". It seems almost like it a problem > with the > class objects (defined in > > https://github.com/cdeterman/gpuR/blob/develop/inst/include/gpuR/dynVCLMat.hpp). > > Any insight would be appreciated. > > Regards, > Charles > > > > ------------------------------------------------------------------------------ > Mobile security can be enabling, not merely restricting. > Employees who > bring their own devices (BYOD) to work are irked by the > imposition of MDM > restrictions. Mobile Device Manager Plus allows you to > control only the > apps on BYO-devices by containerizing them, leaving personal > data untouched! > https://ad.doubleclick.net/ddm/clk/304595813;131938128;j > > > > _______________________________________________ > ViennaCL-devel mailing list > ViennaCL-devel@lists.sourceforge.net > <mailto:ViennaCL-devel@lists.sourceforge.net> > https://lists.sourceforge.net/lists/listinfo/viennacl-devel > > > > ------------------------------------------------------------------------------ Mobile security can be enabling, not merely restricting. Employees who bring their own devices (BYOD) to work are irked by the imposition of MDM restrictions. Mobile Device Manager Plus allows you to control only the apps on BYO-devices by containerizing them, leaving personal data untouched! https://ad.doubleclick.net/ddm/clk/304595813;131938128;j _______________________________________________ ViennaCL-devel mailing list ViennaCL-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/viennacl-devel
