Re: cvs commit: src/sys/conf options src/sys/netinet ip_output.c

From: Sam Leffler <>
Date: Tue, 25 Mar 2003 17:54:55 -0800
> I've been pondering where the tradeoff between avoiding memory copies and
> doing excessive scatter / gather DMA lies.  Perhaps we should be
> defragmenting any chain over a certain amount of length, no matter the
> limit imposed by the card.  This sounds like a Terry question. :)

I hit this in fast ipsec.  I do "agressive coalescing" when creating
writable mbuf chains on output.  It's a big win for various things.  Full
results will be in the paper I'm writing for bsdcon.

Received on Tue Mar 25 2003 - 17:55:20 UTC