use anonymous maps in vmfill

needed on s390 where /dev/zero maps cannot fill all memory.

diff --git a/src/common/vmfill.c b/src/common/vmfill.c
index 32b6cce..d44ad50 100644 (file)
--- a/src/common/vmfill.c
+++ b/src/common/vmfill.c
@@ -7,6 +7,9 @@
 #ifndef PAGE_SIZE
        #define PAGE_SIZE sysconf(_SC_PAGE_SIZE)
 #endif
 #ifndef PAGE_SIZE
        #define PAGE_SIZE sysconf(_SC_PAGE_SIZE)
 #endif

+#ifndef MAP_ANONYMOUS
+       #define MAP_ANONYMOUS 0
+#endif

 
 /* max mmap size, *start is the largest power-of-2 size considered */
 static size_t mmax(int fd, size_t *start)
 
 /* max mmap size, *start is the largest power-of-2 size considered */
 static size_t mmax(int fd, size_t *start)


@@ -15,7 +18,7 @@ static size_t mmax(int fd, size_t *start)
        void *p;
 
        for (i=n=*start; i>=PAGE_SIZE; i/=2) {
        void *p;
 
        for (i=n=*start; i>=PAGE_SIZE; i/=2) {

-               if ((p=mmap(0, n, PROT_NONE, MAP_PRIVATE, fd, 0)) == MAP_FAILED) {
+               if ((p=mmap(0, n, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, fd, 0)) == MAP_FAILED) {

                        n -= i/2;
                } else {
                        munmap(p, n);
                        n -= i/2;
                } else {
                        munmap(p, n);


@@ -34,7 +37,7 @@ the return value is the number of mappings or -1 on failure.
 */
 int t_vmfill(void **p, size_t *n, int len)
 {
 */
 int t_vmfill(void **p, size_t *n, int len)
 {

-       int fd = open("/dev/zero", O_RDWR);
+       int fd = MAP_ANONYMOUS ? -1 : open("/dev/zero", O_RDWR);

        size_t start = SIZE_MAX/2 + 1;
        size_t m;
        void *q;
        size_t start = SIZE_MAX/2 + 1;
        size_t m;
        void *q;


@@ -44,7 +47,7 @@ int t_vmfill(void **p, size_t *n, int len)
                m = mmax(fd, &start);
                if (!m)
                        break;
                m = mmax(fd, &start);
                if (!m)
                        break;

-               q = mmap(0, m, PROT_NONE, MAP_PRIVATE, fd, 0);
+               q = mmap(0, m, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, fd, 0);

                if (q == MAP_FAILED)
                        return -1;
                if (i < len) {
                if (q == MAP_FAILED)
                        return -1;
                if (i < len) {