X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2F44bsd.texi;h=3bbce0d572c2a6b3cc051920fa7caa7906b439ae;hb=ffd63f8d7e284c6d49889666953b581db8a8d0cd;hp=4d61c17afb995b8daf753c6a57ad42f4d1419bf8;hpb=9018e28b2292aef7055eff62d48aa814ad180b12;p=pintos-anon

diff --git a/doc/44bsd.texi b/doc/44bsd.texi
index 4d61c17..3bbce0d 100644
--- a/doc/44bsd.texi
+++ b/doc/44bsd.texi
@@ -52,6 +52,12 @@ time, the scheduler chooses a thread from the highest-priority non-empty
 queue.  If the highest-priority queue contains multiple threads, then
 they run in ``round robin'' order.
 
+Multiple facets of the scheduler require data to be updated after a
+certain number of timer ticks.  In every case, these updates should
+occur before any ordinary kernel thread has a chance to run, so that
+there is no chance that a kernel thread could see a newly increased
+@func{timer_ticks} value but old scheduler data values.
+
 @menu
 * Thread Niceness::             
 * Calculating Priority::        
@@ -75,9 +81,9 @@ time from other threads.
 
 The initial thread starts with a @var{nice} value of zero.  Other
 threads start with a @var{nice} value inherited from their parent
-thread.  You
-must implement these functions, for which we have provided skeleton
-definitions in @file{threads/thread.c}.
+thread.  You must implement the functions described below, which are for
+use by test programs.  We have provided skeleton definitions for them in
+@file{threads/thread.c}.  by test programs
 
 @deftypefun int thread_get_nice (void)
 Returns the current thread's @var{nice} value.