Add TODOs.

[pintos-anon] / TODO

diff --git a/TODO b/TODO
index 31606d182661ee33ae3ceefb616355d5f7daac19..6a1a69f9d29dd3229a5f3531a6a04d929de9213f 100644 (file)
--- a/TODO
+++ b/TODO
@@ -1,13 +1,32 @@
 -*- text -*-
 
-* Miscellaneous:
+* The tests in tests/ don't apply the grading patches.
 
-  - Currently the `pintos' utility has a broken return code policy: it
-    returns 1 to indicate success.  It inherited this mistake from
-    Bochs, which does something similar.  This needs to be fixed.
+* We need better and more example programs.
+
+  - Need an mmap example program as a replacement for the crappy mmap FAQ
+    question.
+
+  - How about `diff' and `cmp' programs?
+
+* Make it clear that the students own their code, because there was some
+  confusion on that point.
+
+* Threads:
+
+  - join-invalid doesn't compile if tid_t is not scalar type.
+
+  - mlfqs tests suck.  They aren't even correct, e.g. the amarv
+    submission from win0405 is graded incorrectly.
 
 * Userprog project:
 
+  - Don't emphasize that stuff needs to be copied from user space to
+    kernel space.  Instead, emphasize validation and suggest that
+    copying is a common solution and that it will be necessary in
+    project 3 and in real OSes.  Also revise the grading criteria to
+    match.
+
   - Move `join' implementation here, from `threads' project, to help
     normalize the project difficulties.
 
@@ -24,6 +43,39 @@
     Alternately we could just remove the synchronization on pid
     selection and check that students fix it.
 
+* VM project:
+
+  - Discuss the perils of mixing dirty bits between kernel and user virtual
+    memory.
+
+  - Sample solution.
+
+  - Update grading/vm to reflect new mmap, munmap forms.
+
+* Filesys project:
+
+  - Increase maximum disk size from 8 MB to something that actually
+    requires doubly indirect nodes.  There is a negative pressure here
+    from the bitmap object--perhaps we need a specialized bitmap that
+    doesn't have to be all in-memory at once.
+
+    Alternatively, shrink the inode size.
+
+  - Add mkdir and ls example user programs.
+
+  - Add option to disable buffer cache.
+
+  - Get rid of "dump" commands--they're not really useful.
+
+  - Sample solution.
+
+  - Need a better way to measure performance improvement of buffer
+    cache.  Some students reported that their system was slower with
+    cache--likely, Bochs doesn't simulate a disk with a realistic
+    speed.
+
+  - Clarify effect of remove(cwd).
+
 * Documentation:
 
   - Finish writing tour.
@@ -40,10 +92,13 @@
 
     . Low-level x86 stuff, like paged page tables.
 
+    . Specifics on how to implement sbrk, malloc.
+
     . Other good ideas.
 
-  - mmap/munmap should use segment IDs like Nachos.  Too hard
-    otherwise.
+    . opendir/readdir/closedir
+
+    . everything needed for getcwd()
 
   - Add src/testcases/vm, src/testcases/filesys and make it clear to use
     them?
@@ -60,3 +115,8 @@
     too long (especially when SHOW_PROGRESS is turned on) and doesn't
     show significant improvement.
 
+* Code:
+
+  - Rewrite quick_sort() to use heap sort, for O(1) stack usage.
+
+  - Rewrite list_sort() to use merge sort, for O(1) heap usage.