On Thu, Mar 09, 2000 at 11:31:14AM -0500, Andrew Gillham wrote:

 > This makes a good "denial of service" attack IMHO.  Your server happily
 > runs along with 'NMBCLUSTERS=1024' for months, and suddenly you lose access
 > to it, have have to rebuild a kernel with 2048.  Oops, that isn't enough,
 > lost access again, try 4096, oops, 8192, oops, 16384.  Whew!  Damn thing
 > is "stable" again.

For what it's worth, in -current on the Alpha port, you can change this
number dynamically at run-time, using the kern.mbuf.nmbclusters sysctl
variable.

You can't do this on the i386 port... the Alpha does it by using a
direct-mapped segment for mapping pool pages.  The i386 can't do this :-)

-- 
        -- Jason R. Thorpe <thorpej@shagadelic.org>