Try to make students think about performance of scheduler dispatching.

[pintos-anon] / doc / threads.texi

diff --git a/doc/threads.texi b/doc/threads.texi
index d1ff66640cd05f9d428375bf6bf0bd91958357ea..a28d7a41d1c14842c8ee65a8ca3bf26c177c4ff8 100644 (file)
--- a/doc/threads.texi
+++ b/doc/threads.texi
@@ -442,8 +442,8 @@ priority such that it no longer has the highest priority must cause it
 to immediately yield the CPU.
 
 Thread priorities range from @code{PRI_MIN} (0) to @code{PRI_MAX} (63).
-Lower numbers correspond to @emph{higher} priorities, so that priority 0
-is the highest priority and priority 63 is the lowest.
+Lower numbers correspond to lower priorities, so that priority 0
+is the lowest priority and priority 63 is the highest.
 The initial thread priority is passed as an argument to
 @func{thread_create}.  If there's no reason to choose another
 priority, use @code{PRI_DEFAULT} (31).  The @code{PRI_} macros are
@@ -675,7 +675,7 @@ list.
 
 @item If the highest-priority thread yields, does it continue running?
 
-Yes.  As long as there is a single highest-priority thread, it continues
+Yes.  If there is a single highest-priority thread, it continues
 running until it blocks or finishes, even if it calls
 @func{thread_yield}.
 If multiple threads have the same highest priority,
@@ -685,8 +685,8 @@ 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 3) donates
-to thread @var{B} (with priority 5), then @var{B}'s new priority is 3, not 8.
+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.
 
 @item Can a thread's priority change while it is on the ready queue?
 
@@ -730,9 +730,6 @@ 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.
+Yes.  In general, your implementation may differ from the description,
+as long as its behavior is the same.
 @end table