X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Fthreads.texi;h=77afeda0e17a49a0062062b16d6c9ba328c705b5;hb=1802b7b7b8d5e3d6754da9468e22942a8c29982b;hp=1093f335636dcc13c85e3bebe944129d97c7beae;hpb=021e47db7a7a0527bc7d0a9eefb25d4f36caace0;p=pintos-anon diff --git a/doc/threads.texi b/doc/threads.texi index 1093f33..77afeda 100644 --- a/doc/threads.texi +++ b/doc/threads.texi @@ -185,8 +185,8 @@ project 3. For now, you can ignore it. @item flags.h Macros that define a few bits in the 80@var{x}86 ``flags'' register. -Probably of no interest. See @bibref{IA32-v1}, section 3.4.3, for more -information. +Probably of no interest. See @bibref{IA32-v1}, section 3.4.3, ``EFLAGS +Register,'' for more information. @end table @menu @@ -511,7 +511,8 @@ must be active, but we must be able to choose the 4.4@acronym{BSD} scheduler with the @option{-mlfqs} kernel option. Passing this option sets @code{enable_mlfqs}, declared in @file{threads/init.h}, to -true. +true when the options are parsed by @func{parse_options}, which happens +midway through @func{main}. When the 4.4@acronym{BSD} scheduler is enabled, threads no longer directly control their own priorities. The @var{priority} argument to @@ -531,6 +532,12 @@ Here's a summary of our reference solution, produced by the @command{diffstat} program. The final row gives total lines inserted and deleted; a changed line counts as both an insertion and a deletion. +The reference solution represents just one possible solution. Many +other solutions are also possible and many of those differ greatly from +the reference solution. Some excellent solutions may not modify all the +files modified by the reference solution, and some may modify files not +modified by the reference solution. + @verbatim devices/timer.c | 42 +++++- threads/fixed-point.h | 120 ++++++++++++++++++ @@ -675,8 +682,8 @@ If multiple threads have the same highest priority, Priority donation only changes the priority of the donee thread. The donor thread's priority is unchanged. -Priority donation is not additive: if thread @var{A} (with priority 5) donates -to thread @var{B} (with priority 3), then @var{B}'s new priority is 5, not 8. +Priority donation is not additive: if thread @var{A} (with priority 3) donates +to thread @var{B} (with priority 5), then @var{B}'s new priority is 3, not 8. @item Can a thread's priority change while it is on the ready queue? @@ -717,4 +724,12 @@ just before the first @func{printf} in @func{main}. Then modify It doesn't have to. We won't test priority donation and the advanced scheduler at the same time. + +@item Can I use one queue instead of 64 queues? + +Yes, that's fine. It's easiest to describe the algorithm in terms of 64 +separate queues, but that doesn't mean you have to implement it that +way. + +If you use a single queue, it should probably be sorted. @end table