Subject: Re: filesystem read-ahead caching....
To: NetBSD Kernel Technical Discussion List <tech-kern@NetBSD.ORG>
From: Jason R Thorpe <>
List: tech-kern
Date: 05/03/2001 16:01:21
On Thu, May 03, 2001 at 05:53:54PM -0400, Greg A. Woods wrote:

 > It seems from a cursory reading of the NetBSD kernel source that there's
 > currently no implementation of read-ahead for FFS, but there does seem
 > to be support for LFS.  Has anyone experimented with adding hooks to
 > cluster_read() to FFS?

If you were looking at -current, then it's because the clustering is
now all done with UBC (using the "clustered pageout" stuff in the
pageout daemon).

That is not to say that cluster pageout couldn't stand some improvement,
but Chuq is working on these issues.

        -- Jason R. Thorpe <>