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[libgomp, nvptx] Handle per-function max-threads-per-block in default dims

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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  <tdevries@suse.de>

	* 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
This commit is contained in:
Tom de Vries 2018-07-30 08:17:26 +00:00 committed by Tom de Vries
parent 0b210c43bb
commit 4cdfee3f20
2 changed files with 31 additions and 4 deletions
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6
libgomp/ChangeLog
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@ -1,3 +1,9 @@
2018-07-30 Tom de Vries <tdevries@suse.de>
* 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 <tdevries@suse.de>
* plugin/plugin-nvptx.c (struct ptx_device): Add default_dims field.

29
libgomp/plugin/plugin-nvptx.c
View File

@ -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