X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=TODO;h=7c9c42b841e0c2f820c789c315eb17f8491d751a;hb=bacf7817544d49aab659f8cb5a56213db23943f0;hp=15902a2cd3db19fd7e77209b9d82127190a96759;hpb=8176d4bd89c45d3b18a3240728ec650d822ab835;p=pintos-anon diff --git a/TODO b/TODO index 15902a2..7c9c42b 100644 --- a/TODO +++ b/TODO @@ -1,12 +1,51 @@ -*- text -*- -* Userprog project: +* Test pintos with GSX. + +* Get rid of warnings for NDEBUG build. + +* Need targets for checking single tests or single subdirs + + - `make check' should say how to get more information + + - `make recheck', `make clean-check' + +* Need to put time limits on tests. + +* Add a way for students to prints messages ignored by the autograder. + + - Ignore text between /* and */. + + - Allow for a comment on `exit' lines? + +* Improve automatic interpretation of exception messages. + +* Remove names from synchronization primitives? They don't seem + useful in practice. + +* debug_backtrace() in kernel should only dereference valid pointers. + +* Mention how to use add-symbol-file in gdb. + +* 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? + +* Threads: - - Move `join' implementation here, from `threads' project, to help - normalize the project difficulties. + - mlfqs tests suck. They aren't even correct, e.g. the amarv + submission from win0405 is graded incorrectly. - - The semantics of the join system call should change so that it - only returns the exit code once. +* 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. - Mark read-only pages as actually read-only in the page table. Or, since this was consistently rated as the easiest project by the @@ -18,6 +57,35 @@ 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 option to disable buffer cache. + + - 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. @@ -28,19 +96,21 @@ - Add explanations of what "real" OSes do to give students some perspective. + - GNU make 3.80 or later is required. + * Assignments: - Add extra credit: . 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 - - Add src/testcases/vm, src/testcases/filesys and make it clear to use - them? + . everything needed for getcwd() * Tests: @@ -54,3 +124,9 @@ too long (especially when SHOW_PROGRESS is turned on) and doesn't show significant improvement. +* Code: + + - Need an optimization barrier and an explanation of it in the + documentation. + + - Need to check the wait system call more thoroughly.