Subject: RE: disk caching
To: None <>
From: Andy Sporner <>
List: tech-kern
Date: 04/12/2000 13:29:51
> > Linux' buffer cache grows and shrinks with the availability 
> of memory,
> > i.e. it's dynamically sized.
> > 

I have looked into this and was amazed at how much better it
has gotten since I first got started in the 1.59 days.

There is a syscall that allows you to program how the BDFLUSH
daemon behaves (establish min/max values for when to flush 
buffers, etc).  The syscall is #134.  There is a pretty good
discussion in the source code about this by reading sort of
between the lines (bad pun! :-))

This only goes to show the superiority in some respects of 
BSD, because I would not have had to spend the last 45 minutes
crawling through code to find this!

This strategy is better at least than it used to be.  At one
point the strategy was that buffers would only be flushed if
the load average was .7 or more, because the assumption was
that there was excessive paging and/or swapping going on!