From 4cdfee3f206d784f8a502af4f34180a0762df4fe Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Mon, 30 Jul 2018 08:17:26 +0000 Subject: [PATCH] [libgomp, nvptx] Handle per-function max-threads-per-block in default dims Currently parallel-loop-1.c fails at -O0 on a Quadro M1200, because one of the kernel launch configurations exceeds the resources available in the device, due to the default dimensions chosen by the runtime. This patch fixes that by taking the per-function max_threads_per_block into account when using the default dimensions. 2018-07-30 Tom de Vries * plugin/plugin-nvptx.c (MIN, MAX): Redefine. (nvptx_exec): Ensure worker and vector default dims don't exceed targ_fn->max_threads_per_block. From-SVN: r263062 --- libgomp/ChangeLog | 6 ++++++ libgomp/plugin/plugin-nvptx.c | 29 +++++++++++++++++++++++++---- 2 files changed, 31 insertions(+), 4 deletions(-) diff --git a/libgomp/ChangeLog b/libgomp/ChangeLog index 1d218f4be6c..6cd30bbf49d 100644 --- a/libgomp/ChangeLog +++ b/libgomp/ChangeLog @@ -1,3 +1,9 @@ +2018-07-30 Tom de Vries + + * plugin/plugin-nvptx.c (MIN, MAX): Redefine. + (nvptx_exec): Ensure worker and vector default dims don't exceed + targ_fn->max_threads_per_block. + 2018-07-30 Tom de Vries * plugin/plugin-nvptx.c (struct ptx_device): Add default_dims field. diff --git a/libgomp/plugin/plugin-nvptx.c b/libgomp/plugin/plugin-nvptx.c index 5c522aaf281..b6ec5f88d59 100644 --- a/libgomp/plugin/plugin-nvptx.c +++ b/libgomp/plugin/plugin-nvptx.c @@ -141,6 +141,11 @@ init_cuda_lib (void) #include "secure_getenv.h" +#undef MIN +#undef MAX +#define MIN(X,Y) ((X) < (Y) ? (X) : (Y)) +#define MAX(X,Y) ((X) > (Y) ? (X) : (Y)) + /* Convenience macros for the frequently used CUDA library call and error handling sequence as well as CUDA library calls that do the error checking themselves or don't do it at all. */ @@ -1135,6 +1140,7 @@ nvptx_exec (void (*fn), size_t mapnum, void **hostaddrs, void **devaddrs, void *kargs[1]; void *hp, *dp; struct nvptx_thread *nvthd = nvptx_thread (); + int warp_size = nvthd->ptx_dev->warp_size; const char *maybe_abort_msg = "(perhaps abort was called)"; function = targ_fn->fn; @@ -1175,7 +1181,6 @@ nvptx_exec (void (*fn), size_t mapnum, void **hostaddrs, void **devaddrs, int gang, worker, vector; { - int warp_size = nvthd->ptx_dev->warp_size; int block_size = nvthd->ptx_dev->max_threads_per_block; int cpu_size = nvthd->ptx_dev->max_threads_per_multiprocessor; int dev_size = nvthd->ptx_dev->num_sms; @@ -1213,9 +1218,25 @@ nvptx_exec (void (*fn), size_t mapnum, void **hostaddrs, void **devaddrs, } pthread_mutex_unlock (&ptx_dev_lock); - for (i = 0; i != GOMP_DIM_MAX; i++) - if (!dims[i]) - dims[i] = nvthd->ptx_dev->default_dims[i]; + { + bool default_dim_p[GOMP_DIM_MAX]; + for (i = 0; i != GOMP_DIM_MAX; i++) + { + default_dim_p[i] = !dims[i]; + if (default_dim_p[i]) + dims[i] = nvthd->ptx_dev->default_dims[i]; + } + + if (default_dim_p[GOMP_DIM_VECTOR]) + dims[GOMP_DIM_VECTOR] + = MIN (dims[GOMP_DIM_VECTOR], + (targ_fn->max_threads_per_block / warp_size * warp_size)); + + if (default_dim_p[GOMP_DIM_WORKER]) + dims[GOMP_DIM_WORKER] + = MIN (dims[GOMP_DIM_WORKER], + targ_fn->max_threads_per_block / dims[GOMP_DIM_VECTOR]); + } } /* Check if the accelerator has sufficient hardware resources to -- 2.30.2