X-Git-Url: http://git.vrable.net/?a=blobdiff_plain;f=microbench%2Flockmem.c;fp=microbench%2Flockmem.c;h=c0ea9d2258449ae454baf98db185bd8d3609cfab;hb=1d1d7431b759d5027929362bdc668ccd64db6753;hp=0000000000000000000000000000000000000000;hpb=c1f4367b3c65b01562bc6484226dff0135cd4780;p=bluesky.git

diff --git a/microbench/lockmem.c b/microbench/lockmem.c
new file mode 100644
index 0000000..c0ea9d2
--- /dev/null
+++ b/microbench/lockmem.c
@@ -0,0 +1,38 @@
+/* A very simple program to lock a specified amount of memory (in megabytes)
+ * into memory.  Used to decrease the available amount of free memory on a
+ * system for benchmarking purposes. */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+int main(int argc, char *argv[])
+{
+    if (argc != 2) {
+        fprintf(stderr,
+                "Usage: %s <amount in MiB>\n"
+                "Locks the specified number of megabytes of RAM.\n",
+                argv[0]);
+        return 1;
+    }
+
+    size_t bufsize = atoi(argv[1]) << 20;
+    char *buf = malloc(bufsize);
+    if (buf == NULL) {
+        fprintf(stderr, "Unable to allocate buffer: %m\n");
+        return 1;
+    }
+
+    if (mlock(buf, bufsize) < 0) {
+        fprintf(stderr, "Unable to lock memory: %m\n");
+        return 1;
+    }
+
+    /* Infinite loop; simply wait for the program to be killed. */
+    while (1) {
+        sleep(3600);
+    }
+
+    return 0;
+}