Merge branch 'multicore-eff'

2 files changed, 48 insertions, 4 deletions

diff --git a/fractal-gen.c b/fractal-gen.c
index 7f4e326..c5930c9 100644
--- a/fractal-gen.c
+++ b/fractal-gen.c
@@ -56,6 +56,24 @@ defaultsd(double *who, double def)
 		*who = def;
 }
 
+double
+timespec_diff(struct timespec start, struct timespec end) {
+	long weight = 1000000000;
+	time_t s = (end.tv_sec - start.tv_sec);
+	long ns = (end.tv_nsec - start.tv_nsec) % weight;
+
+	return s + ((double)ns)/weight;
+}
+
+void
+*generate(void *section) {
+	data_section *s = (data_section*)section;
+	clock_gettime(CLOCK_THREAD_CPUTIME_ID, &(s->time_start));
+	(s->generator)(s);
+	clock_gettime(CLOCK_THREAD_CPUTIME_ID, &(s->time_end));
+	return NULL;
+}
+
 int
 main(int argc, char **argv)
 {
@@ -107,6 +125,10 @@ main(int argc, char **argv)
 		ram_nice /= 1024;
 	}
 
+	/* FIXME clean up */
+	struct timespec time_start, time_end;
+	clock_gettime(CLOCK_REALTIME, &time_start);
+
 	fprintf(stderr,
 		"Forecast resource use:\n"
 		" Threads: %d\n"
@@ -142,10 +164,11 @@ main(int argc, char **argv)
 		sections[i].width = width;
 		sections[i].parent_frame.y = f.y;
 		sections[i].parent_frame.x = f.x;
+		sections[i].generator = generator;
 		sections[i].parent_frame.scale = f.scale;
 		sections[i].datasize = toalloc;
 		fprintf(stderr, " -> Thread %lu\r", i);
-		pthread_create(&sections[i].thread, NULL, generator, &(sections[i]));
+		pthread_create(&sections[i].thread, NULL, generate, &(sections[i]));
 	}
 
 	s = &(sections[cores-1]);
@@ -170,6 +193,24 @@ main(int argc, char **argv)
 
 	kill(child, SIGKILL);
 
+	clock_gettime(CLOCK_REALTIME, &time_end);
+
+	fprintf(stderr, "\nDone\n");
+
+	double time_wall = timespec_diff(time_start, time_end);
+	double time_ch = 0;
+
+	for (i = 0; i < cores; i++) {
+		data_section *s = &(sections[i]);
+		time_ch += (timespec_diff(s->time_start, s->time_end)) / cores;
+	}
+
+	fprintf(stderr,
+		"Wall-clock time: %.2f seconds\n"
+		"Average worker time: %.2f seconds\n"
+		"Multi-core efficiency: %.2f%%\n"
+		, time_wall, time_ch, 100*(time_ch)/time_wall);
+
 	/* Output PGM Header */
 	printf("P5\n%d\n%d\n255\n",size,size/clust_total);
 
@@ -182,7 +223,6 @@ main(int argc, char **argv)
 			putchar(s->data[y*(s->width) + x/cores]);
 		}
 	}
-	fprintf(stderr, "\nDone\n");
 
 	/* Free the memory we allocated for point data */
 	for (i = 0; i < cores; i++)
diff --git a/fractal-gen.h b/fractal-gen.h
index 210d50f..8dcd167 100644
--- a/fractal-gen.h
+++ b/fractal-gen.h
@@ -28,16 +28,21 @@
 #include <stdbool.h>
 #include <pthread.h>
 
+typedef void* (*generator_func)(void *);
+
 struct frame {
 	double x;
 	double y;
 	double scale;
 };
 
-typedef struct {
+typedef struct data_section_s {
 	volatile unsigned long idx;
+	generator_func generator;
 	struct frame parent_frame;
 	unsigned long core;
+	struct timespec time_start;
+	struct timespec time_end;
 	unsigned long width;
 	unsigned long datasize;
 	char* data;
@@ -53,7 +58,6 @@ double power;
 double thread_mult; /* number to multiply available cores by to get thread count */
 char *argv0;
 
-typedef void* (*generator_func)(void *);
 
 void defaultsd(double*, double);
 int parse_args(int argc, char **argv);