Already answered...

Forum: Tour of the Linux kernel source
Re: Do you still need to run bdflush? (Steve Dunham)
Keywords: kflushd, searching
Date: Mon, 27 May 1996 19:42:00 GMT
From: Michael K. Johnson <johnsonm@redhat.com>

It looks like I'll eventually have to add search capability to the KHG. It will be a while before I have time, though. Your questions is already answered in a response elsewhere in this document; see Kernel threads, posted by Paul Gortmaker.