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