Subject: Re: disk caching
To: None <>
From: Thor Lancelot Simon <>
List: tech-kern
Date: 04/14/2000 02:09:02
On Thu, Apr 13, 2000 at 10:36:56PM -0500, wrote:
> On Thu, Apr 13, 2000 at 10:49:19PM -0400, Thor Lancelot Simon wrote:
> > On Thu, Apr 13, 2000 at 10:38:50PM +0200, Manuel Bouyer wrote:
> > There are some very common cases which are pathological for the algorithm
> > we have in that its performance degrades to that of the old "flush all
> > buffers every 30 seconds of wall-clock time" method.  For example, if
> > you have a system that does most of its I/O to a single file... you lose.
> > 
> > On the other hand, the "right" way is pretty hard to do with UBC.  What
> > do you do, attach a timeval to every page?
> 	How about if you place individual buffers instead of vnodes in the
> syncer's work list?  And add a VOP_FSYNCBUF which only flushed the specified
> buffer.

When "buffers" are just lists of pages, what are you going to do, put
individual pages there?