On Wed, Apr 04, 2001 at 06:42:25PM -0000, eeh@netbsd.org wrote:
> 
> 	I think this is the problem. We don't seem to make a difference between
> 	recently-used pages for a file we are writing, and recently-used pages
> 	by text or data process. When writing a large file I guess the most recently
> 	used pages are the ones for the file's data, and the pagedaemon free pages of
> 	programs instead. Maybe the pagedaemon should first free pages of file
> 	data ?
> 
> That's also done by my patch.  (At least that's what I thought when I wrote
> the patch.)  Pages are immediately cleaned and put onto the idle list.  Of
> course this implementation could cause other performance problems, like 
> multiple writes of the same page, and does chew up lot's of CPU time.

Doesn't this also basically defeat the write-behind nature of the buffer
cache and make all I/O if not synchronous, quite close to it?

-- 
Thor Lancelot Simon	                                      tls@rek.tjls.com
    And now he couldn't remember when this passion had flown, leaving him so
  foolish and bewildered and astray: can any man?
						   William Styron