3 * debug_backtrace() in kernel should only dereference valid pointers.
5 * Mention how to use add-symbol-file in gdb.
7 * We need better and more example programs.
9 - Need an mmap example program as a replacement for the crappy mmap FAQ
12 - How about `diff' and `cmp' programs?
16 - mlfqs tests suck. They aren't even correct, e.g. the amarv
17 submission from win0405 is graded incorrectly.
21 - Don't emphasize that stuff needs to be copied from user space to
22 kernel space. Instead, emphasize validation and suggest that
23 copying is a common solution and that it will be necessary in
24 project 3 and in real OSes. Also revise the grading criteria to
27 - Mark read-only pages as actually read-only in the page table. Or,
28 since this was consistently rated as the easiest project by the
29 students, require them to do it.
31 - Don't provide per-process pagedir implementation but only
32 single-process implementation and require students to implement
33 the separation? This project was rated as the easiest after all.
34 Alternately we could just remove the synchronization on pid
35 selection and check that students fix it.
39 - Discuss the perils of mixing dirty bits between kernel and user virtual
44 - Update grading/vm to reflect new mmap, munmap forms.
48 - Increase maximum disk size from 8 MB to something that actually
49 requires doubly indirect nodes. There is a negative pressure here
50 from the bitmap object--perhaps we need a specialized bitmap that
51 doesn't have to be all in-memory at once.
53 Alternatively, shrink the inode size.
55 - Add option to disable buffer cache.
59 - Need a better way to measure performance improvement of buffer
60 cache. Some students reported that their system was slower with
61 cache--likely, Bochs doesn't simulate a disk with a realistic
64 - Clarify effect of remove(cwd).
68 - Finish writing tour.
70 - Add "Digging Deeper" sections that describe the nitty-gritty x86
71 details for the benefit of those interested.
73 - Add explanations of what "real" OSes do to give students some
76 - GNU make 3.80 or later is required.
82 . Low-level x86 stuff, like paged page tables.
84 . Specifics on how to implement sbrk, malloc.
88 . opendir/readdir/closedir
90 . everything needed for getcwd()
94 - Release some of them.
96 - The threads, userprog, vm test source files could use
97 factorization and cleanup along the lines of fslib in the filesys
100 - The p1-4.c testcase needs significant tuning. Currently it takes
101 too long (especially when SHOW_PROGRESS is turned on) and doesn't
102 show significant improvement.
106 - Need an optimization barrier and an explanation of it in the
109 - Need to check the wait system call more thoroughly.