perf util: Make the timechart SVG width dynamic

This patch adds a command line option for timechart that allows the
user to specify the width of the SVG file.

This patch also makes sure that each second of recording has at
least 200 units (pixels at 96 DPI) of width.  This impacts
recordings longer than 5 seconds; recordings shorter than 5 second
will scale up to have a width of 1000 units for the whole recording
(as before).
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20090920181416.69570c5d@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

tools/perf/Documentation/perf-timechart.txt

@@ -28,6 +28,9 @@ OPTIONS
 -i::
 --input=::
         Select the input file (default: perf.data)
+-w::
+--width=::
+        Select the width of the SVG file (default: 1000)
 
 
 SEE ALSO

tools/perf/builtin-timechart.c

@@ -915,9 +915,9 @@ static void write_svg_file(const char *filename)
 	if (count < 15)
 		count = determine_display_tasks(TIME_THRESH / 10);
 
-	open_svg(filename, numcpus, count);
+	open_svg(filename, numcpus, count, first_time, last_time);
 
-	svg_time_grid(first_time, last_time);
+	svg_time_grid();
 	svg_legenda();
 
 	for (i = 0; i < numcpus; i++)
@@ -1132,6 +1132,8 @@ static const struct option options[] = {
 		    "input file name"),
 	OPT_STRING('o', "output", &output_name, "file",
 		    "output file name"),
+	OPT_INTEGER('w', "width", &svg_page_width,
+		    "page width"),
 	OPT_END()
 };
 

tools/perf/util/svghelper.c

@@ -25,7 +25,8 @@ static u64 turbo_frequency, max_freq;
 
 #define SLOT_MULT 30.0
 #define SLOT_HEIGHT 25.0
-#define WIDTH 1000.0
+
+int svg_page_width = 1000;
 
 #define MIN_TEXT_SIZE 0.001
 
@@ -46,21 +47,35 @@ static double time2pixels(u64 time)
 {
 	double X;
 
-	X = WIDTH * (time - first_time) / (last_time - first_time);
+	X = 1.0 * svg_page_width * (time - first_time) / (last_time - first_time);
 	return X;
 }
 
-void open_svg(const char *filename, int cpus, int rows)
+void open_svg(const char *filename, int cpus, int rows, u64 start, u64 end)
 {
+	int new_width;
 
 	svgfile = fopen(filename, "w");
 	if (!svgfile) {
 		fprintf(stderr, "Cannot open %s for output\n", filename);
 		return;
 	}
+	first_time = start;
+	first_time = first_time / 100000000 * 100000000;
+	last_time = end;
+
+	/*
+	 * if the recording is short, we default to a width of 1000, but
+	 * for longer recordings we want at least 200 units of width per second
+	 */
+	new_width = (last_time - first_time) / 5000000;
+
+	if (new_width > svg_page_width)
+		svg_page_width = new_width;
+
 	total_height = (1 + rows + cpu2slot(cpus)) * SLOT_MULT;
 	fprintf(svgfile, "<?xml version=\"1.0\" standalone=\"no\"?> \n");
-	fprintf(svgfile, "<svg width=\"%4.1f\" height=\"%llu\" version=\"1.1\" xmlns=\"http://www.w3.org/2000/svg\">\n", WIDTH, total_height);
+	fprintf(svgfile, "<svg width=\"%i\" height=\"%llu\" version=\"1.1\" xmlns=\"http://www.w3.org/2000/svg\">\n", svg_page_width, total_height);
 
 	fprintf(svgfile, "<defs>\n  <style type=\"text/css\">\n    <![CDATA[\n");
 
@@ -404,15 +419,10 @@ void svg_legenda(void)
 	svg_legenda_box(800,	"Blocked on IO", "blocked");
 }
 
-void svg_time_grid(u64 start, u64 end)
+void svg_time_grid(void)
 {
 	u64 i;
 
-	first_time = start;
-	last_time = end;
-
-	first_time = first_time / 100000000 * 100000000;
-
 	if (!svgfile)
 		return;
 

tools/perf/util/svghelper.h

@@ -3,7 +3,7 @@
 
 #include "types.h"
 
-extern void open_svg(const char *filename, int cpus, int rows);
+extern void open_svg(const char *filename, int cpus, int rows, u64 start, u64 end);
 extern void svg_box(int Yslot, u64 start, u64 end, const char *type);
 extern void svg_sample(int Yslot, int cpu, u64 start, u64 end);
 extern void svg_waiting(int Yslot, u64 start, u64 end);
@@ -15,7 +15,7 @@ extern void svg_cstate(int cpu, u64 start, u64 end, int type);
 extern void svg_pstate(int cpu, u64 start, u64 end, u64 freq);
 
 
-extern void svg_time_grid(u64 start, u64 end);
+extern void svg_time_grid(void);
 extern void svg_legenda(void);
 extern void svg_wakeline(u64 start, int row1, int row2);
 extern void svg_partial_wakeline(u64 start, int row1, char *desc1, int row2, char *desc2);
@@ -23,4 +23,6 @@ extern void svg_interrupt(u64 start, int row);
 extern void svg_text(int Yslot, u64 start, const char *text);
 extern void svg_close(void);
 
+extern int svg_page_width;
+
 #endif