mm: move hugepage test examples to tools/testing/selftests/vm

hugepage-mmap.c, hugepage-shm.c and map_hugetlb.c in Documentation/vm are
simple pass/fail tests, It's better to promote them to
tools/testing/selftests.

Thanks suggestion of Andrew Morton about this.  They all need firstly
setting up proper nr_hugepages and hugepage-mmap need to mount hugetlbfs.
So I add a shell script run_vmtests to do such work which will call the
three test programs and check the return value of them.

Changes to original code including below:
a. add run_vmtests script
b. return error when read_bytes mismatch with writed bytes.
c. coding style fixes: do not use assignment in if condition

[akpm@linux-foundation.org: build the targets before trying to execute them]
[akpm@linux-foundation.org: Documentation/vm/ no longer has a Makefile. Fixes "make clean"]
Signed-off-by: Dave Young <dyoung@redhat.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/Makefile

@@ -1,3 +1,3 @@
 obj-m := DocBook/ accounting/ auxdisplay/ connector/ \
 	filesystems/ filesystems/configfs/ ia64/ laptops/ networking/ \
-	pcmcia/ spi/ timers/ vm/ watchdog/src/
+	pcmcia/ spi/ timers/ watchdog/src/

Documentation/vm/Makefile

@@ -1,8 +0,0 @@
-# kbuild trick to avoid linker error. Can be omitted if a module is built.
-obj- := dummy.o
-
-# List of programs to build
-hostprogs-y := hugepage-mmap hugepage-shm map_hugetlb
-
-# Tell kbuild to always build the programs
-always := $(hostprogs-y)

tools/testing/selftests/Makefile

@@ -1,4 +1,4 @@
-TARGETS = breakpoints
+TARGETS = breakpoints vm
 
 all:
 	for TARGET in $(TARGETS); do \

tools/testing/selftests/vm/Makefile

@@ -0,0 +1,14 @@
+# Makefile for vm selftests
+
+CC = $(CROSS_COMPILE)gcc
+CFLAGS = -Wall -Wextra
+
+all: hugepage-mmap hugepage-shm  map_hugetlb
+%: %.c
+	$(CC) $(CFLAGS) -o $@ $^
+
+run_tests: all
+	/bin/sh ./run_vmtests
+
+clean:
+	$(RM) hugepage-mmap hugepage-shm  map_hugetlb

tools/testing/selftests/vm/hugepage-mmap.c

@@ -22,7 +22,7 @@
 #include <sys/mman.h>
 #include <fcntl.h>
 
-#define FILE_NAME "/mnt/hugepagefile"
+#define FILE_NAME "huge/hugepagefile"
 #define LENGTH (256UL*1024*1024)
 #define PROTECTION (PROT_READ | PROT_WRITE)
 
@@ -48,7 +48,7 @@ static void write_bytes(char *addr)
 		*(addr + i) = (char)i;
 }
 
-static void read_bytes(char *addr)
+static int read_bytes(char *addr)
 {
 	unsigned long i;
 
@@ -56,14 +56,15 @@ static void read_bytes(char *addr)
 	for (i = 0; i < LENGTH; i++)
 		if (*(addr + i) != (char)i) {
 			printf("Mismatch at %lu\n", i);
-			break;
+			return 1;
 		}
+	return 0;
 }
 
 int main(void)
 {
 	void *addr;
-	int fd;
+	int fd, ret;
 
 	fd = open(FILE_NAME, O_CREAT | O_RDWR, 0755);
 	if (fd < 0) {
@@ -81,11 +82,11 @@ int main(void)
 	printf("Returned address is %p\n", addr);
 	check_bytes(addr);
 	write_bytes(addr);
-	read_bytes(addr);
+	ret = read_bytes(addr);
 
 	munmap(addr, LENGTH);
 	close(fd);
 	unlink(FILE_NAME);
 
-	return 0;
+	return ret;
 }

tools/testing/selftests/vm/hugepage-shm.c

@@ -57,8 +57,8 @@ int main(void)
 	unsigned long i;
 	char *shmaddr;
 
-	if ((shmid = shmget(2, LENGTH,
-			    SHM_HUGETLB | IPC_CREAT | SHM_R | SHM_W)) < 0) {
+	shmid = shmget(2, LENGTH, SHM_HUGETLB | IPC_CREAT | SHM_R | SHM_W);
+	if (shmid < 0) {
 		perror("shmget");
 		exit(1);
 	}
@@ -82,14 +82,16 @@ int main(void)
 
 	dprintf("Starting the Check...");
 	for (i = 0; i < LENGTH; i++)
-		if (shmaddr[i] != (char)i)
+		if (shmaddr[i] != (char)i) {
 			printf("\nIndex %lu mismatched\n", i);
+			exit(3);
+		}
 	dprintf("Done.\n");
 
 	if (shmdt((const void *)shmaddr) != 0) {
 		perror("Detach failure");
 		shmctl(shmid, IPC_RMID, NULL);
-		exit(3);
+		exit(4);
 	}
 
 	shmctl(shmid, IPC_RMID, NULL);

tools/testing/selftests/vm/map_hugetlb.c

@@ -44,7 +44,7 @@ static void write_bytes(char *addr)
 		*(addr + i) = (char)i;
 }
 
-static void read_bytes(char *addr)
+static int read_bytes(char *addr)
 {
 	unsigned long i;
 
@@ -52,13 +52,15 @@ static void read_bytes(char *addr)
 	for (i = 0; i < LENGTH; i++)
 		if (*(addr + i) != (char)i) {
 			printf("Mismatch at %lu\n", i);
-			break;
+			return 1;
 		}
+	return 0;
 }
 
 int main(void)
 {
 	void *addr;
+	int ret;
 
 	addr = mmap(ADDR, LENGTH, PROTECTION, FLAGS, 0, 0);
 	if (addr == MAP_FAILED) {
@@ -69,9 +71,9 @@ int main(void)
 	printf("Returned address is %p\n", addr);
 	check_bytes(addr);
 	write_bytes(addr);
-	read_bytes(addr);
+	ret = read_bytes(addr);
 
 	munmap(addr, LENGTH);
 
-	return 0;
+	return ret;
 }

tools/testing/selftests/vm/run_vmtests

@@ -0,0 +1,77 @@
+#!/bin/bash
+#please run as root
+
+#we need 256M, below is the size in kB
+needmem=262144
+mnt=./huge
+
+#get pagesize and freepages from /proc/meminfo
+while read name size unit; do
+	if [ "$name" = "HugePages_Free:" ]; then
+		freepgs=$size
+	fi
+	if [ "$name" = "Hugepagesize:" ]; then
+		pgsize=$size
+	fi
+done < /proc/meminfo
+
+#set proper nr_hugepages
+if [ -n "$freepgs" ] && [ -n "$pgsize" ]; then
+	nr_hugepgs=`cat /proc/sys/vm/nr_hugepages`
+	needpgs=`expr $needmem / $pgsize`
+	if [ $freepgs -lt $needpgs ]; then
+		lackpgs=$(( $needpgs - $freepgs ))
+		echo $(( $lackpgs + $nr_hugepgs )) > /proc/sys/vm/nr_hugepages
+		if [ $? -ne 0 ]; then
+			echo "Please run this test as root"
+			exit 1
+		fi
+	fi
+else
+	echo "no hugetlbfs support in kernel?"
+	exit 1
+fi
+
+mkdir $mnt
+mount -t hugetlbfs none $mnt
+
+echo "--------------------"
+echo "runing hugepage-mmap"
+echo "--------------------"
+./hugepage-mmap
+if [ $? -ne 0 ]; then
+	echo "[FAIL]"
+else
+	echo "[PASS]"
+fi
+
+shmmax=`cat /proc/sys/kernel/shmmax`
+shmall=`cat /proc/sys/kernel/shmall`
+echo 268435456 > /proc/sys/kernel/shmmax
+echo 4194304 > /proc/sys/kernel/shmall
+echo "--------------------"
+echo "runing hugepage-shm"
+echo "--------------------"
+./hugepage-shm
+if [ $? -ne 0 ]; then
+	echo "[FAIL]"
+else
+	echo "[PASS]"
+fi
+echo $shmmax > /proc/sys/kernel/shmmax
+echo $shmall > /proc/sys/kernel/shmall
+
+echo "--------------------"
+echo "runing map_hugetlb"
+echo "--------------------"
+./map_hugetlb
+if [ $? -ne 0 ]; then
+	echo "[FAIL]"
+else
+	echo "[PASS]"
+fi
+
+#cleanup
+umount $mnt
+rm -rf $mnt
+echo $nr_hugepgs > /proc/sys/vm/nr_hugepages