Performance models files are now stored in a directory whose name

include the version of the performance model format. The version
number is also written in the file itself.

When updating the format, the internal variable
_STARPU_PERFMODEL_VERSION should be updated. It is then possible
to switch easily between differents versions of StarPU having
different performance model formats.

ChangeLog

@@ -40,6 +40,13 @@ New features:
     handle (sequential consistency will be enabled or disabled based
     on the value of the function parameter and the value of the
     sequential consistency defined for the given data)
+  * Performance models files are now stored in a directory whose name
+    include the version of the performance model format. The version
+    number is also written in the file itself.
+    When updating the format, the internal variable
+    _STARPU_PERFMODEL_VERSION should be updated. It is then possible
+    to switch easily between differents versions of StarPU having
+    different performance model formats.
 
 Small features:
   * Add cl_arg_free field to enable automatic free(cl_arg) on task

src/core/perfmodel/perfmodel.c

@@ -426,8 +426,9 @@ void _starpu_get_perf_model_dir(char *path, size_t maxlen)
 
 void _starpu_get_perf_model_dir_codelets(char *path, size_t maxlen)
 {
-	_starpu_get_perf_model_dir(path, maxlen);
-	strncat(path, "/codelets/", maxlen);
+	char perf_model_path[256];
+	_starpu_get_perf_model_dir(perf_model_path, maxlen);
+	snprintf(path, maxlen, "%s/codelets/%d/", perf_model_path, _STARPU_PERFMODEL_VERSION);
 }
 
 void _starpu_get_perf_model_dir_bus(char *path, size_t maxlen)

src/core/perfmodel/perfmodel.h

@@ -29,6 +29,17 @@ extern "C"
 {
 #endif
 
+/**
+ * Performance models files are stored in a directory whose name
+ * include the version of the performance model format. The version
+ * number is also written in the file itself.
+ * When updating the format, the variable _STARPU_PERFMODEL_VERSION
+ * should be updated. It is then possible to switch easily between
+ * differents versions of StarPU having different performance model
+ * formats.
+ */
+#define _STARPU_PERFMODEL_VERSION 42
+
 struct _starpu_perfmodel_list
 {
 	struct _starpu_perfmodel_list *next;

src/core/perfmodel/perfmodel_history.c

@@ -295,6 +295,13 @@ static void parse_arch(FILE *f, struct starpu_perfmodel *model, unsigned scan_hi
 static void parse_device(FILE *f, struct starpu_perfmodel *model, unsigned scan_history, unsigned * arch, unsigned archmax)
 {
 	unsigned maxncore, ncore, ret;
+	int version;
+
+	/* Parsing performance model version */
+	_starpu_drop_comments(f);
+	ret = fscanf(f, "%d\n", &version);
+	STARPU_ASSERT_MSG(version == _STARPU_PERFMODEL_VERSION, "Incorrect performance model file with a model version %d not being the current model version (%d)\n",
+			  version, _STARPU_PERFMODEL_VERSION);
 
 	/* Parsing maximun number of worker for this device */
 	_starpu_drop_comments(f);
@@ -419,6 +426,10 @@ static void dump_model_file(FILE *f, struct starpu_perfmodel *model)
 	unsigned nimpl;
 	unsigned idx = 0;
 
+	fprintf(f, "##################\n");
+	fprintf(f, "# Performance Model Version\n");
+	fprintf(f, "%d\n\n", _STARPU_PERFMODEL_VERSION);
+
 	/* Finding the number of archs to write for each kind of device */
 	for (arch = 0; arch < STARPU_NARCH_VARIATIONS; arch++)
 	{
@@ -888,7 +899,7 @@ void _starpu_load_history_based_model(struct starpu_perfmodel *model, unsigned s
 		else
 		{
 			/* We load the available file */
-			_STARPU_DEBUG("File exists\n");
+                        _STARPU_DEBUG("File exists\n");
 			FILE *f;
 			f = fopen(path, "r");
 			STARPU_ASSERT(f);