mmap: Check if size exceeds available memory when MAP_HUGETLB

If size exceeds, mmap fails and set -ENOMEM

Change-Id: I4f0d6e18ee3a7c8e32e251b7ed07ee9f76305603
Refs: #1183

test/issues/1183/hugemap.c

@@ -0,0 +1,73 @@
+#include <stdio.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+
+#define MAP_HUGE_SHIFT 26
+
+void print_usage(void)
+{
+	printf("usage: hugemap <total_mapsize(GB)> <mapsize(GB)> <pgshift>\n");
+}
+
+int mmap_flag(size_t mapsize, int page_shift)
+{
+	char *addr_mmap;
+	int flags = MAP_ANONYMOUS | MAP_PRIVATE;
+
+	if (page_shift >= 0) {
+		/* mean use MAP_HUGETLB */
+		flags |= MAP_HUGETLB | (page_shift << MAP_HUGE_SHIFT);
+	}
+
+	addr_mmap = mmap(0, mapsize,
+			PROT_READ | PROT_WRITE,
+			flags, -1, 0);
+
+	if (addr_mmap == MAP_FAILED) {
+		return 1;
+	}
+
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	int ret;
+	int i;
+	unsigned long maptotal;
+	size_t mapsize;
+	int pgshift;
+
+	void *addr = NULL;
+
+	if (argc < 4) {
+		print_usage();
+		return 1;
+	}
+
+	maptotal = atol(argv[1]) << 30;
+	mapsize = atol(argv[2]) << 30;
+	pgshift = atoi(argv[3]);
+
+	printf("*** total_mapsize: %ld GB, mapsize: %ld pgshift: %d\n",
+		maptotal >> 30, mapsize >> 30, pgshift);
+
+	for (i = 0; i < maptotal / mapsize; i++) {
+		printf("** mmap %ld GB: ", mapsize >> 30);
+
+		ret = mmap_flag(mapsize, pgshift);
+
+		if (ret != 0) {
+			printf("failed\n");
+			goto out;
+		}
+		else {
+			printf("succeed\n");
+		}
+	}
+	printf("** all mmaps succeeded\n");
+out:
+	return ret;
+}