Update docs.

[pintos-anon] / doc / vm.texi

diff --git a/doc/vm.texi b/doc/vm.texi
index bf53bf8ee17ddb977347f488737c5554fdc2bc7f..260f9d99c751fce1a3c211e04cbd9119be7f202a 100644 (file)
--- a/doc/vm.texi
+++ b/doc/vm.texi
@@ -374,6 +374,12 @@ pages less frequently using your algorithm than using some inferior
 page replacement policy.  The canonical example of a poor page
 replacement policy is random replacement.
 
+You must write your code so that we can choose a page replacement policy
+at compile time.  By default, the LRU-like algorithm must be in effect,
+but we must be able to choose random replacement by inserting the line
+@code{#define RANDOM_REPLACEMENT 1} in @file{constants.h}.
+@xref{Conditional Compilation}, for details.
+
 Since you will already be paging from disk, you should implement a
 ``lazy'' loading scheme for new processes.  When a process is created,
 it will not run immediately.  Therefore, it doesn't make sense to load