interrupt handling latency, which can make a machine feel sluggish if
taken too far.
+You may need to add or modify code where interrupts are already
+disabled, such as in @func{sema_up} or @func{sema_down}. You should
+still try to keep this code as short as you can.
+
Disabling interrupts can be useful for debugging, if you want to make
sure that a section of code is not interrupted. You should remove
-debugging code before turning in your project.
+debugging code before turning in your project. (Don't just comment it
+out, because that can make the code difficult to read.)
There should be no busy waiting in your submission. A tight loop that
calls @func{thread_yield} is one form of busy waiting.
donation, before you start work on the advanced scheduler.
You must write your code so that we can choose a scheduling algorithm
-policy at Pintos startup time. By default, the round-robin scheduler
+policy at Pintos startup time. By default, the priority scheduler
must be active, but we must be able to choose the 4.4@acronym{BSD}
scheduler
with the @option{-mlfqs} kernel option. Passing this
@func{thread_set_priority}, and @func{thread_get_priority} should return
the thread's current priority as set by the scheduler.
+The 4.4@acronym{BSD} scheduler does not implement priority donation.
+
The advanced scheduler is not used in any later project.
@node Project 1 FAQ