Add getpid to measure the performance of system calls

regression/apps/getpid/getpid.c

@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: MPL-2.0
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <sys/syscall.h>
+#include <time.h>
+#include <unistd.h>
+
+#define NUM_OF_CALLS 1000000
+
+int main()
+{
+	struct timespec start, end;
+	long seconds, nanoseconds, total_nanoseconds, avg_latency;
+	pid_t pid;
+
+	clock_gettime(CLOCK_MONOTONIC, &start);
+
+	for (int i = 0; i < NUM_OF_CALLS; i++) {
+		pid = syscall(SYS_getpid);
+	}
+
+	clock_gettime(CLOCK_MONOTONIC, &end);
+
+	seconds = end.tv_sec - start.tv_sec;
+	nanoseconds = end.tv_nsec - start.tv_nsec;
+
+	total_nanoseconds = seconds * 1e9 + nanoseconds;
+	avg_latency = total_nanoseconds / NUM_OF_CALLS;
+
+	printf("Process %d executed the getpid() syscall %d times.\n", pid,
+	       NUM_OF_CALLS);
+	printf("Syscall average latency: %ld nanoseconds.\n", avg_latency);
+
+	return 0;
+}