X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2F44bsd.texi;h=d49f23490281312499a91d2d00ef9e7bd9f6c91d;hb=4879d73c341778a907b777da3a6a15a131c5a913;hp=2269cdc629eeed0aff0653a3a0412da340bf7458;hpb=ea69fc9dbb8d947fbec0e78fe266c6402c112731;p=pintos-anon diff --git a/doc/44bsd.texi b/doc/44bsd.texi index 2269cdc..d49f234 100644 --- a/doc/44bsd.texi +++ b/doc/44bsd.texi @@ -86,7 +86,7 @@ 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 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 +@file{threads/thread.c}. @deftypefun int thread_get_nice (void) Returns the current thread's @var{nice} value. @@ -237,14 +237,13 @@ nearest integer. @node 4.4BSD Scheduler Summary @section Summary -This section summarizes the calculations required to implement the -scheduler. It is not a complete description of scheduler requirements. +The following formulas summarize the calculations required to implement the +scheduler. They are not a complete description of scheduler requirements. Every thread has a @var{nice} value between -20 and 20 directly under its control. Each thread also has a priority, between 0 (@code{PRI_MIN}) through 63 (@code{PRI_MAX}), which is recalculated -using the following formula whenever the value of either variable term -changes: +using the following formula every fourth tick: @center @t{@var{priority} = @code{PRI_MAX} - (@var{recent_cpu} / 4) - (@var{nice} * 2)}.