Re: [PATCH, 1/4] Show value of GOMP_OPENACC_DIM in libgomp nvptx plugin

[Tom de Vries]

On 06/26/2017 01:31 PM, Tom de Vries wrote:

On 06/26/2017 01:24 PM, Tom de Vries wrote:

Hi,

I've written a patch series to facilitate debugging libgomp openacc testcase failures on the nvptx accelerator.

When running an openacc test-case on an nvptx accelerator, the following happens:

- the plugin obtains the ptx assembly for the acceleration kernels
- it calls the cuda jit to compile and link the ptx into a module
- it loads the module
- it starts an acceleration kernel

The patch series adds these environment variables:
- GOMP_OPENACC_NVPTX_SAVE_TEMPS: a means to save the resulting module
   such that it can be investigated using nvdisasm and cuobjdump.
- GOMP_OPENACC_NVPTX_DISASM: a means to see the resulting module in
   the debug output,  by writing it into a file and calling nvdisasm on
   it
- GOMP_OPENACC_NVPTX_JIT: a means to set parameters of the
   compilation/linking process, currently supporting:
   * -O[0-4], mapping onto CU_JIT_OPTIMIZATION_LEVEL
   * -ori, mapping onto CU_JIT_NEW_SM3X_OPT


The patch series consists of these patches:

1. Show value of GOMP_OPENACC_DIM in libgomp nvptx plugin

This patch adds a debug message (for GOMP_DEBUG=1) about the value of the GOMP_OPENACC_DIM variable read from the environment.

Committed as trivial.

Thanks,
- Tom

Thanks,
- Tom

0001-Show-value-of-GOMP_OPENACC_DIM-in-libgomp-nvptx-plugin.patch


Show value of GOMP_OPENACC_DIM in libgomp nvptx plugin

2017-06-26  Tom de Vries  <t...@codesourcery.com>

        * plugin/plugin-nvptx.c (notify_var): New function.
        (nvptx_exec): Use notify_var for GOMP_OPENACC_DIM.

---
  libgomp/plugin/plugin-nvptx.c | 12 +++++++++++-
  1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/libgomp/plugin/plugin-nvptx.c b/libgomp/plugin/plugin-nvptx.c
index 0e1b3e2..71630b5 100644
--- a/libgomp/plugin/plugin-nvptx.c
+++ b/libgomp/plugin/plugin-nvptx.c
@@ -867,6 +867,14 @@ nvptx_get_num_devices (void)
    return n;
  }

+static void

+notify_var (const char *var_name, const char *env_var)
+{
+  if (env_var == NULL)
+    GOMP_PLUGIN_debug (0, "%s: <Not defined>\n", var_name);
+  else
+    GOMP_PLUGIN_debug (0, "%s: '%s'\n", var_name, env_var);
+}

static bool

  link_ptx (CUmodule *module, const struct targ_ptx_obj *ptx_objs,
@@ -1089,10 +1097,12 @@ nvptx_exec (void (*fn), size_t mapnum, void 
**hostaddrs, void **devaddrs,
        pthread_mutex_lock (&ptx_dev_lock);
        if (!default_dims[0])
        {
+         const char *var_name = "GOMP_OPENACC_DIM";
          /* We only read the environment variable once.  You can't
             change it in the middle of execution.  The syntax  is
             the same as for the -fopenacc-dim compilation option.  */
-         const char *env_var = getenv ("GOMP_OPENACC_DIM");
+         const char *env_var = getenv (var_name);
+         notify_var (var_name, env_var);
          if (env_var)
            {
              const char *pos = env_var;