Limit printing to terminal height in intel_gpu_top.

When using intel_gpu_top in a small terminal, the most important
information (ring idle/busy units) scrolls off the top of the screen.
This patch limits the number of lines printed to the terminal height
so that the most idle units (at the bottom) are truncated instead.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>

1 files changed, 15 insertions, 5 deletions

diff --git a/tools/intel_gpu_top.c b/tools/intel_gpu_top.c
index d314edaf..9ef3ae4d 100644
--- a/tools/intel_gpu_top.c
+++ b/tools/intel_gpu_top.c
@@ -29,6 +29,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <err.h>
+#include <sys/ioctl.h>
 #include "intel_gpu_tools.h"
 #include "instdone.h"
 
@@ -257,6 +258,13 @@ int main(int argc, char **argv)
 		qsort(top_bits_sorted, num_instdone_bits,
 		      sizeof(struct top_bit *), top_bits_sort);
 
+		/* Limit the number of lines printed to the terminal height so the
+		 * most important info (at the top) will stay on screen. */
+		unsigned short int max_lines = -1;
+		struct winsize ws;
+		if (ioctl(0, TIOCGWINSZ, &ws) != -1)
+			max_lines = ws.ws_row - 6; /* exclude header lines */
+
 		printf("%s", clear_screen);
 
 		print_clock_info();
@@ -275,11 +283,13 @@ int main(int argc, char **argv)
 			if (top_bits_sorted[i]->count < 1)
 				break;
 
-			percent = top_bits_sorted[i]->count / SAMPLES_TO_PERCENT_RATIO;
-			len = printf("%30s: %3d%%: ",
-				     top_bits_sorted[i]->bit->name,
-				     percent);
-			print_percentage_bar (percent, len);
+			if (i < max_lines) {
+				percent = top_bits_sorted[i]->count / SAMPLES_TO_PERCENT_RATIO;
+				len = printf("%30s: %3d%%: ",
+					     top_bits_sorted[i]->bit->name,
+					     percent);
+				print_percentage_bar (percent, len);
+			}
 
 			top_bits_sorted[i]->count = 0;
 		}