In my tests here this tremendously speeds up things when initializing a
1G file from /dev/urandom
#include "user-util.h"
#include "xattr-util.h"
-/* If we copy via a userspace buffer, size it to 16K */
-#define COPY_BUFFER_SIZE (16U*1024U)
+/* If we copy via a userspace buffer, size it to 64K */
+#define COPY_BUFFER_SIZE (64U*U64_KB)
/* If a byte progress function is specified during copying, never try to copy more than 1M, so that we can
* reasonably call the progress function still */