bgwriter_lru_multiplier blurbs inconsistent

Is the bgwriter_lru_multiplier parameter a limit on the number to scan
or to write?  GUC and docs seem to contradict one another.  GUC says

#: utils/misc/guc.c:1834
#, fuzzy
msgid "Background writer multiplier on average buffers to scan per round."

The docs say

         Unless limited by <varname>bgwriter_lru_maxpages</>, the number
         of dirty buffers written in each round is determined by reference
         to the number of new buffers that have been needed by server
         processes during recent rounds.  This number is multiplied by
         <varname>bgwriter_lru_multiplier</> to arrive at the estimate
         of the number of buffers that will be needed during the next round.


Which one is correct?  Do we need a correction of either?

--
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.