doc: improve description of "niceness" values

* doc/coreutils.texi (nice invocation):

diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index f42e73670251eeeabbd3bc5801f027504b8df974..206f8dd823500335e3c9415878bf915c9af5f9a1 100644 (file)
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -13533,8 +13533,10 @@ If no arguments are given, @command{nice} prints the current niceness.
 Otherwise, @command{nice} runs the given @var{command} with its
 niceness adjusted.  By default, its niceness is incremented by 10.
 
-Nicenesses range at least from @minus{}20 (resulting in the most
-favorable scheduling) through 19 (the least favorable).  Some systems
+Niceness values range at least from @minus{}20 (process has high priority
+and gets more resources, thus slowing down other processes) through 19
+(process has lower priority and runs slowly itself, but has less impact
+on the speed of other running processes).  Some systems
 may have a wider range of nicenesses; conversely, other systems may
 enforce more restrictive limits.  An attempt to set the niceness
 outside the supported range is treated as an attempt to use the