Re: Handling of short frames in gem(4) (was: CVS commit: src/sys/dev/ic)

[David Laight <david%l8s.co.uk@localhost>]

On Wed, Jan 02, 2008 at 03:40:19PM -0600, David Young wrote:
> 
> If you
> mean that scatter/gather is expensive, then let us see some measurements
> of how expensive.

Years ago, somewone I know got a break-even point of about 1k [1] for an
mbus/sbus sparc system (running a SYSV variant).  I've also got significant
improvements from removing 'buffer loaning' and all its complications
by inserting a data copy from a solaris (old) FDDI driver.

        David

[1] I'm also not sure he ensured the data copies where aligned (test data
wouldn't have been IP).

-- 
David Laight: david%l8s.co.uk@localhost