From 3ad98707c78ba6c1bf59d22d29d5d1229dbb7132 Mon Sep 17 00:00:00 2001
From: Wenchao Hao <haowenchao22@gmail.com>
Date: Mon, 21 Oct 2024 23:35:32 +0800
Subject: [PATCH] update

Signed-off-by: Wenchao Hao <haowenchao22@gmail.com>
---
 madvise.c | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 madvise.c

diff --git a/madvise.c b/madvise.c
new file mode 100644
index 0000000..1d6ad1b
--- /dev/null
+++ b/madvise.c
@@ -0,0 +1,36 @@
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/time.h>
+
+unsigned long long tv_to_ms(struct timeval tv)
+{
+	return tv.tv_sec * 1000 + tv.tv_usec / 1000;
+}
+
+void main()
+{
+	struct timeval tv_b, tv_e;;
+#define SIZE 400*1024*1024
+	void *p = mmap(NULL, SIZE, PROT_READ | PROT_WRITE,
+				MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	if (!p) {
+		perror("fail to get memory");
+		exit(-1);
+	}
+
+	madvise(p, SIZE, MADV_HUGEPAGE);
+	memset(p, 0x11, SIZE); /* write to get mem */
+
+	gettimeofday(&tv_b, NULL);
+	madvise(p, SIZE, MADV_PAGEOUT);
+	gettimeofday(&tv_e, NULL);
+
+	printf("swp out bandwidth: %ld bytes/ms\n",
+			SIZE/(tv_to_ms(tv_e) - tv_to_ms(tv_b)));
+}