X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=TODO;h=6a1a69f9d29dd3229a5f3531a6a04d929de9213f;hb=8df7142a8c2337dd184ebd1b2ab4347b400a5453;hp=9e332a36a320dc0d4fc6b927d2e35a0e0737e3e7;hpb=c95f2f01e84c7579f3230ae82899c907de9a2526;p=pintos-anon

diff --git a/TODO b/TODO
index 9e332a3..6a1a69f 100644
--- a/TODO
+++ b/TODO
@@ -1,20 +1,80 @@
 -*- text -*-
 
-* Code:
+* The tests in tests/ don't apply the grading patches.
+
+* 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.
+
+  - The semantics of the join system call should change so that it
+    only returns the exit code once.
+
+  - Mark read-only pages as actually read-only in the page table.  Or,
+    since this was consistently rated as the easiest project by the
+    students, require them to do it.
+
+  - Don't provide per-process pagedir implementation but only
+    single-process implementation and require students to implement
+    the separation?  This project was rated as the easiest after all.
+    Alternately we could just remove the synchronization on pid
+    selection and check that students fix it.
 
-  - Speed up disk routines: filling an 8 MB disk takes a long time.
-    (They're only slow because timer_sleep always waits for at least
-    one timer tick.)
+* VM project:
 
-  - userprog project should mark read-only pages as actually read-only
-    in the page table.  Or, since this was consistently rated as the
-    easiest project by the students, require them to do it.
+  - Discuss the perils of mixing dirty bits between kernel and user virtual
+    memory.
 
-  - For userprog project, don't provide per-process pagedir
-    implementation but only single-process implementation and require
-    students to implement the separation?  This project was rated as
-    the easiest after all.  Alternately we could just remove the
-    synchronization on pid selection and check that students fix it.
+  - 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:
 
@@ -32,13 +92,13 @@
 
     . Low-level x86 stuff, like paged page tables.
 
+    . Specifics on how to implement sbrk, malloc.
+
     . Other good ideas.
 
-  - The semantics of the join system call should change so that it
-    only returns the exit code once.
+    . opendir/readdir/closedir
 
-  - mmap/munmap should use segment IDs like Nachos.  Too hard
-    otherwise.
+    . everything needed for getcwd()
 
   - Add src/testcases/vm, src/testcases/filesys and make it clear to use
     them?
@@ -55,3 +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.