Preload all of the normal SLURM plugins used by the slurmstepd. Avoids

the possibility of processes forked from slurmstepd needing to dlopen
plugin libraries.

src/common/mpi.c

@@ -236,9 +236,8 @@ done:
 	return retval;
 }
 
-
-int mpi_hook_slurmstepd_task (const mpi_plugin_task_info_t *job, char ***env)
-{   
+int mpi_hook_slurmstepd_init (char ***env)
+{
 	char *mpi_type = getenvp (*env, "SLURM_MPI_TYPE");
 	
 	debug("mpi type = %s", mpi_type);
@@ -247,6 +246,15 @@ int mpi_hook_slurmstepd_task (const mpi_plugin_task_info_t *job, char ***env)
 		return SLURM_ERROR;
 	
 	unsetenvp (*env, "SLURM_MPI_TYPE");
+
+	return SLURM_SUCCESS;
+}
+
+int mpi_hook_slurmstepd_task (const mpi_plugin_task_info_t *job, char ***env)
+{   
+	if (mpi_hook_slurmstepd_init(env) == SLURM_ERROR)
+		return SLURM_ERROR;
+
 	return (*(g_context->ops.slurmstepd_init))(job, env);
 }
 

src/common/mpi.h

@@ -74,7 +74,19 @@ typedef struct {
  **********************************************************************/
 
 /*
- * Load the plugin and call the plugin p_mpi_hook_slurmstepd_task() function.
+ * Just load the requested plugin.  No explicit calls into the plugin
+ * once loaded (just the implicit call to the plugin's init() function).
+ *
+ * The MPI module type is passed through an environment variable
+ * SLURM_MPI_TYPE from the client.  There is no more official protocol.
+ * This function will remove SLURM_MPI_TYPE from the environment variable
+ * array "env", if it exists.
+ */
+int mpi_hook_slurmstepd_init (char ***env);
+
+/*
+ * Load the plugin (if not already loaded) and call the plugin
+ * p_mpi_hook_slurmstepd_task() function.
  *
  * This function is called from within each process that will exec() a
  * task.  The process will be running as the user of the job step at that

src/common/slurm_jobacct.c

@@ -294,6 +294,14 @@ static int _slurm_jobacct_fini(void)
 	return rc;
 }
 
+extern int jobacct_init(void)
+{
+	if (_slurm_jobacct_init() < 0)
+		return SLURM_ERROR;
+
+	return SLURM_SUCCESS;
+}
+
 extern int jobacct_g_init_struct(jobacctinfo_t *jobacct, 
 				 jobacct_id_t *jobacct_id)
 {

src/common/slurm_jobacct.h

@@ -66,6 +66,7 @@
 #include "src/sacct/sacct_stat.h"
 
 /* common */
+extern int jobacct_init(void); /* load the plugin */
 extern int jobacct_g_init_struct(jobacctinfo_t *jobacct, 
 				 jobacct_id_t *jobacct_id);
 /* must free jobacctinfo_t if not NULL */

src/slurmd/slurmstepd/mgr.c

@@ -647,7 +647,14 @@ job_manager(slurmd_job_t *job)
 
 	debug3("Entered job_manager for %u.%u pid=%lu",
 	       job->jobid, job->stepid, (unsigned long) job->jmgr_pid);
-	if (slurm_proctrack_init() != SLURM_SUCCESS) {
+	/*
+	 * Preload plugins.
+	 */
+	if (switch_init() != SLURM_SUCCESS
+	    || slurmd_task_init() != SLURM_SUCCESS
+	    || mpi_hook_slurmstepd_init(&job->env) != SLURM_SUCCESS
+	    || slurm_proctrack_init() != SLURM_SUCCESS
+	    || jobacct_init() != SLURM_SUCCESS) {
 		rc = SLURM_FAILURE;
 		goto fail1;
 	}