iowatcher: Fix some rounding errors around the max offset

[blktrace.git] / iowatcher / plot.c

diff --git a/iowatcher/plot.c b/iowatcher/plot.c
index 79e5d3cefc07fad3574af852a835270b036b8e0b..1e9b7d7345612e999142e4e2e62a4dbae7f0867d 100644 (file)
--- a/iowatcher/plot.c
+++ b/iowatcher/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;