schulung_tools: add various demos and tools

Different tools have been used by various trainers as demos. Put
all these into master so they are available to all trainers.

ipc_pipe: ipc demo using pipes
ipc_shm: ipc demo using shared memory
libduma: source and instructions for compiling libduma
matrix: demo of good and bad cache access
mtrace: patch and infos for using mtrace with ASLR
rtex: demo of handling page faults

Signed-off-by: John Ogness <john.ogness@linutronix.de>

1 files changed, 69 insertions, 0 deletions

diff --git a/schulung_tools/rtex/func.c b/schulung_tools/rtex/func.c
new file mode 100644
index 0000000..4b88166
--- /dev/null
+++ b/schulung_tools/rtex/func.c
@@ -0,0 +1,69 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+
+void timestamp(const char *msg, int val)
+{
+	static struct timespec tsl;
+	static long minfltl;
+
+	struct timespec ts;
+	unsigned long diff;
+	struct rusage r;
+	long rdiff;
+
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	getrusage(RUSAGE_SELF, &r);
+
+	if (tsl.tv_sec != 0) {
+		diff = (ts.tv_sec - tsl.tv_sec) * 1000000000;
+		diff += ts.tv_nsec - tsl.tv_nsec;
+
+		rdiff = r.ru_minflt - minfltl;
+
+		printf("% 10d ns % 5ld faults : %s", diff, rdiff, msg);
+		if (val >= 0)
+			printf(" (%d)", val);
+		printf("\n");
+	}
+
+	tsl = ts;
+	minfltl = r.ru_minflt;
+}
+
+/* 10 MiB */
+#define SIZE (10 * 1024 * 1024)
+
+void testfunc_malloc(void)
+{
+	char *p;
+
+	p = malloc(SIZE);
+	if (!p) {
+		fprintf(stderr, "MALLOC FAILED: %s:%d\n", __FILE__, __LINE__);
+		return;
+	}
+
+	memset(p, 42, SIZE);
+
+	if (p[SIZE - 1] != 42)
+		fprintf(stderr, "MEMSET FAILED: %s:%d\n", __FILE__, __LINE__);
+
+	free(p);
+}
+
+void recursive_stack(int i)
+{
+	char buf[1024];
+	if (i > 0)
+		recursive_stack(i - 1);
+}
+
+void testfunc_deepstack(void)
+{
+	char buf[1024];
+	recursive_stack(7 * 1024);
+}