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