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Hi, I am using LLVM 3.6.1 to test the following code: #include <omp.h> #include <stdio.h> #include <stdlib.h> int main() { int tid, nthreads; #pragma omp parallel sections private(nthreads, tid) { #pragma omp section { tid = omp_get_thread_num(); printf("Hello, tid = %d\n ", tid); } #pragma omp section { tid = omp_get_thread_num(); printf("Hello, tid = %d\n ", tid); } } if (tid =...

I got this to work on Linux but it is not working on Windows. *My understanding is that this should also work on windows, is that correct?* If so, what should I do? differently? To get it to work on Linux, I modified my R script as follows: #' OpenMP Hello World #' #' @param nthreads The number of threads that you want to use #' @example #' hello(nthreads=2) #' @export #' @useDynLib helloOpenMP, .registration = TRUE hello <- function(nthreads=4) { (OpenMPController::omp_set_num_threads(nthreads)) .Fortran("hello") return('Each thread wi...

Dear R experts, recently I started developing a Rcpp package "OpenMPTest". Within that package I want to use OpenMP, as in the following code example: // header file #include <omp.h> using namespace Rcpp ; RcppExport SEXP testOpenMP( SEXP nThreads ) ; // cpp file SEXP testOpenMP( SEXP nThreads ) { BEGIN_RCPP NumericVector numberThreads = NumericVector( nThreads ); omp_set_num_threads( numberThreads(0) ); #pragma omp parallel { // Code inside this region runs in parallel. printf("Hello!\n"); } END_RCPP } A...

Hi everybody! Could somebody help me with the following? I'm trying to run a simple Hello World code in openmp using .C function. The C code i have is: #include <omp.h> #include <stdio.h> #include <R.h> void hello_omp(int *n) { int th_id, nthreads; omp_set_num_threads(*n); #pragma omp parallel private(th_id) { th_id = omp_get_thread_num(); Rprintf("Hello World from thread %d\n", th_id); #pragma omp barrier if ( th_id == 0 ) { nthreads = omp_get_num_threads(); Rprintf("There are %d th...

...ver 12746: 7.445: FileServer Version 1.14 2005/06/21 21:18:52 personality successfully loaded 12746: 7.445: Usage: set $dir=<dir> 12746: 7.445: set $filesize=<size> defaults to 131072 12746: 7.445: set $nfiles=<value> defaults to 1000 12746: 7.445: set $nthreads=<value> defaults to 100 12746: 7.445: set $meaniosize=<value> defaults to 16384 12746: 7.445: set $meandirwidth=<size> defaults to 20 12746: 7.445: (sets mean dir width and dir depth is calculated as log (width, nfiles) 12746: 7.445: 12746: 7.445: run runti...

Hi everybody, I'm trying to develop an R package with Fortran and OpenMP. I wrote a simple hello world but I'm not able to set the number of threads. I found this old email chain <http://r.789695.n4.nabble.com/Set-the-number-of-threads-using-openmp-with-C-td2284685.html> and I tried to set my compile instructions accordingly but i had no luck. *This is my makevars:*

...family = "poisson", n.cores=2) range(gbmpred1$Predictions) [1] 10.04643 31.39230 # the expected predictions # Here are results from xgboost # use count:poisson library(xgboost) xgbst2.1 <- xgboost(data = as.matrix(sponge[, -c(3)]), label = sponge[, 3], max_depth = 2, eta = 0.001, nthread = 6, nrounds = 3000, objective = "count:poisson") xgbstpred2 <- predict(xgbst2.1, as.matrix(sponge.grid)) head(xgbstpred2) range(xgbstpred2) [1] 1.109032 4.083049 # much lower than expected table(xgbstpred2) 1.10903215408325 1.26556181907654 3.578040599823 4.0...

I am trying to parallelize part of a C function that is called from R (via .C) using OpenMP's "parallel for" pragma. I get mixed results: some runs finish with no problem, but some lead to R crashing after issuing a long error message involving memory violations. I found this post, which describes how a .Call() function can be made to avoid crashing R by raising the stack limit:

...irectives. When compiling the code in gfortran 4.4 does not occur any problem. When compiling the code in gfortran 4.6, an error message appears. In other compilers the error does not occur. A small example. ## Code in Fortran        subroutine hello()        implicit none        integer :: nthreads, tid        integer :: omp_get_num_threads, omp_get_thread_num        integer :: omp_get_max_threads, omp_set_num_threads        print *, 'Máximo de threads', omp_get_max_threads()        !$omp parallel         tid = omp_get_thread_num()        print *, 'Hello World from thread = ...

...unt = std::min(MAX, std::max(NUMBER_OF_THREADS, NUMBER_OF_CORES)) > > Threads do not produce contention, it's cores that produce contention. > The formula must be: shard_count = k*NCORES > And if you want less memory in single-threaded case, then: shard_count = > min(k*NCORES, c*NTHREADS) > > > > >We are talking about developers here. Nobody would know the exact thread > counts, but developers know the ballpark number > > I strongly believe that we must relief developers from this choice during > build time, and do our best to auto-tune (if the final sch...

...irectives. When compiling the code in gfortran 4.4 does not occur any problem. When compiling the code in gfortran 4.6, an error message appears. In other compilers the error does not occur. A small example. ## Code in Fortran        subroutine hello()        implicit none        integer :: nthreads, tid        integer :: omp_get_num_threads, omp_get_thread_num        integer :: omp_get_max_threads, omp_set_num_threads        print *, 'Máximo de threads', omp_get_max_threads()        !$omp parallel         tid = omp_get_thread_num()        print *, 'Hello World from thread = ...

...hdd/fs32k; $statsdir=/export/home/abdullah/bench.stat/woow87; stats = /export/home/abdullah/bench.stat; filesystem = zfs; description = "ZFS-RR-WS-10M"; } CONFIG rr32k { function = generic; personality = randomread; filesize = 5g; iosize = 32k; nthreads = 1; workingset=10m; } And the Run result .... abdullah at HP_HDX_16:/usr/benchmarks/filebench/config# filebench rrws10m parsing profile for config: rr32k Creating Client Script /export/home/abdullah/bench.stat/HP_HDX_16-zfs-rrws10m-Mar_2_2010-03h_10m_46s/rr32k/thisrun.f Running /export/hom...

On Apr 17, 2014, at 2:04 PM, Chandler Carruth <chandlerc at google.com> wrote: > On Thu, Apr 17, 2014 at 1:27 PM, Justin Bogner <mail at justinbogner.com> wrote: > Chandler Carruth <chandlerc at google.com> writes: > > if (thread-ID != main's thread-ID && shard_count < std::min(MAX, NUMBER_OF_CORES)) { > > shard_count = std::min(MAX,

...gt;> NUMBER_OF_CORES)) >>> >>> Threads do not produce contention, it's cores that produce contention. >>> The formula must be: shard_count = k*NCORES >>> And if you want less memory in single-threaded case, then: shard_count = >>> min(k*NCORES, c*NTHREADS) >>> >>> >>> >>> >We are talking about developers here. Nobody would know the exact >>> thread counts, but developers know the ballpark number >>> >>> I strongly believe that we must relief developers from this choice >>> d...

...AC_LANG_PROGRAM( + [[ + #include <unistd.h> + ]] , [[ + sysconf(_SC_NPROCESSORS_CONF); + ]] + ) + ] , [ + AC_DEFINE([HAVE___SC_NPROCESSORS_CONF],[],[Whether sysconf(_SC_NPROCESSORS_CONF) is supported.]) + AC_MSG_RESULT([yes]) + ssh_agent_options="$ssh_agent_options nthreads:auto" + ] , [ + AC_MSG_RESULT([no]) + AC_MSG_WARN([ssh-agent: do not use threading by default]) + ssh_agent_options="$ssh_agent_options nthreads:manual,default=0" + ] + ) +fi + # Check for PAM libs PAM_MSG="no" AC_ARG_WITH([pam], @@ -4285,6 +4362,7 @@ echo &quo...

...function. The pointer refers to an array of values, one for each thread that will execute the region. After the region completes, a loop must be created to actually perform the requested reduction. Inside the parallel region, each thread accesses its value using its thread id as the index. See the nthreads and tidx intrinsics below. -- Special handling regions -- - Serial Regions - Serial regions within parallel blocks (called 'single' in OpenMP) are executed only by one thread. As with parallel regions themselves, they are lowered as functions; the call site(s) of these functions are tag...

The vendor wanted to come in and replace an HDD in the 2nd X4500, as it was "constantly busy", and since our x4500 has always died miserably in the past when a HDD dies, they wanted to replace it before the HDD actually died. The usual was done, HDD replaced, resilvering started and ran for about 50 minutes. Then the system hung, same as always, all ZFS related commands would just

This patch series resurrects the earlier multiple TX/RX queues functionality for virtio_net, and addresses the issues pointed out. It also includes an API to share irq's, f.e. amongst the TX vqs. I plan to run TCP/UDP STREAM and RR tests for local->host and local->remote, and send the results in the next couple of days. patch #1: Introduce VIRTIO_NET_F_MULTIQUEUE patch #2: Move

This patch series resurrects the earlier multiple TX/RX queues functionality for virtio_net, and addresses the issues pointed out. It also includes an API to share irq's, f.e. amongst the TX vqs. I plan to run TCP/UDP STREAM and RR tests for local->host and local->remote, and send the results in the next couple of days. patch #1: Introduce VIRTIO_NET_F_MULTIQUEUE patch #2: Move