From: Matt Mullins <mmullins@mmlx.us>
Date: Sat, 21 Sep 2013 03:37:56 +0000 (-0700)
Subject: Keep a count of how many pages allocated
X-Git-Url: http://git.mmlx.us/?a=commitdiff_plain;h=93fcb3c831c0cc09895d3f68079d8255f30e01cc;p=mmap_everything.git

Keep a count of how many pages allocated
---

diff --git a/mmap_everything.c b/mmap_everything.c
index 2940a11..bc52ec6 100644
--- a/mmap_everything.c
+++ b/mmap_everything.c
@@ -4,21 +4,41 @@
 #include <stdio.h>
 #include <unistd.h>
 
+#define MAX_BITS (sizeof(size_t) * CHAR_BIT - 1)
+
 int main() {
 	pid_t pid = getpid();
 	printf("My pid is: %d\n", pid);
 
-	size_t size = ((size_t)1 << (sizeof(size_t) * CHAR_BIT - 1));
+	size_t allocated[MAX_BITS+1];
+	for (size_t i = 0; i <= MAX_BITS; ++i) {
+		allocated[i] = 0;
+	}
+
+	size_t size = ((size_t)1 << MAX_BITS);
+	size_t bit = MAX_BITS;
 
 	void *p;
 	do {
 		do {
 			p = mmap(0, size, PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-		} while (p != MAP_FAILED);
+			if (p != MAP_FAILED) {
+				allocated[bit]++;
+			} else {
+				break;
+			}
+		} while (1);
 		
 		size >>= 1;
+		bit--;
 	} while (size);
-	printf("Mapped at: %p\n", p);
+
+	printf("Mapped the following sizes:\n");
+	for (size_t i = 0; i <= MAX_BITS; ++i) {
+		if (allocated[i] != 0) {
+			printf("%zu\t%zu\n", i, allocated[i]);
+		}
+	}
 
 	getchar();
 }