Fix some rounding errors around the max offset

set_gdd_bit makes sure that we don't try to set bits past the max offset
we used to allocate our gdd array.

But, it only does this when the function is first called, and the whole
byte range for the IO we're recording may go past max offset.  This adds
a check to be sure we stay in the right range.

Signed-off-by: Chris Mason <chris.mason@fusionio.com>

2 files changed, 4 insertions, 5 deletions

diff --git a/main.c b/main.c
index 23fb707..6e392f2 100644
--- a/main.c
+++ b/main.c
@@ -297,8 +297,8 @@ static void read_traces(void)
 
 		last_time = find_last_time(trace);
 		tf->trace = trace;
-		tf->max_seconds = SECONDS(last_time);
-		tf->stop_seconds = SECONDS(last_time);
+		tf->max_seconds = SECONDS(last_time) + 1;
+		tf->stop_seconds = SECONDS(last_time) + 1;
 		find_extreme_offsets(trace, &tf->min_offset, &tf->max_offset,
 				    &max_bank, &max_bank_offset);
 		filter_outliers(trace, tf->min_offset, tf->max_offset, &ymin, &ymax);
diff --git a/plot.c b/plot.c
index 79e5d3c..1e9b7d7 100644
--- a/plot.c
+++ b/plot.c
@@ -148,7 +148,7 @@ struct graph_dot_data *alloc_dot_data(int min_seconds, int max_seconds, u64 min_
 	arr_size = (rows + 1) * cols;
 
 	/* the number of bytes */
-	arr_size /= 8;
+	arr_size = (arr_size + 7) / 8;
 
 	gdd = calloc(1, size + arr_size);
 	if (!gdd) {
@@ -191,10 +191,9 @@ void set_gdd_bit(struct graph_dot_data *gdd, u64 offset, double bytes, double ti
 
 	if (offset > gdd->max_offset || offset < gdd->min_offset)
 		return;
-
 	gdd->total_ios++;
 	time = time / 1000000000.0;
-	while (bytes > 0) {
+	while (bytes > 0 && offset <= gdd->max_offset) {
 		row = (double)(offset - gdd->min_offset) / bytes_per_row;
 		col = (time - gdd->min_seconds) / secs_per_col;