test: add test that verifies proper intraction between lazy-pages and THP

Acked-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

test/zdtm/transition/Makefile

@@ -20,6 +20,7 @@ TST_NOFILE	=	\
 		socket-tcp      \
 		socket-tcp6     \
 		shmem		\
+		lazy-thp	\
 
 
 TST_FILE	=	\

test/zdtm/transition/lazy-thp.c

+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <linux/limits.h>
+#include "zdtmtst.h"
+
+#define N_PAGES 1024
+
+const char *test_doc	= "Test interaction between THP and lazy-pages";
+
+/* The test is based on example by Adrian Reber <areber@redhat.com> */
+const char *test_author	= "Mike Rapoport <rppt@linux.vnet.ibm.com>";
+
+int main(int argc, char ** argv)
+{
+	char *mem, *org, *m;
+	int count;
+
+	test_init(argc, argv);
+
+	/* we presume that malloc returns not page aliged address */
+	mem = malloc(PAGE_SIZE * N_PAGES);
+	org = malloc(PAGE_SIZE);
+	if (!mem || !org) {
+		fail("malloc failed\n");
+		exit(1);
+	}
+
+	memset(mem, 0x42, PAGE_SIZE * N_PAGES);
+	memset(org, 0x42, PAGE_SIZE);
+
+	test_daemon();
+	while (test_go()) {
+		for (count = 0; count < N_PAGES; count += 2) {
+			m = mem + (count * PAGE_SIZE) + 128;
+			*m = count;
+		}
+
+		for (count = 0; count < N_PAGES; count++) {
+			m = mem+(count*PAGE_SIZE);
+			org[128] = (count % 2 == 0) ? count : 0x42;
+
+			if (memcmp(org, m, PAGE_SIZE)) {
+				fail("memory corruption\n");
+				return 1;
+			}
+		}
+
+		sleep(1);
+	}
+
+	pass();
+	return 0;
+}