From owner-freebsd-hackers Tue Feb 20 21:39:31 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id VAA08161 for hackers-outgoing; Tue, 20 Feb 1996 21:39:31 -0800 (PST) Received: from baygull.rtd.com (baygull.rtd.com [198.102.68.5]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id VAA08156 for ; Tue, 20 Feb 1996 21:39:28 -0800 (PST) Received: (from news@localhost) by baygull.rtd.com (8.6.9/8.6.9.1) id WAA14972; Tue, 20 Feb 1996 22:39:15 -0700 To: hackers@freebsd.org Path: freefall.freebsd.org!owner-freebsd-hackers From: davidg@Root.COM (David Greenman) Newsgroups: rtd.freebsd.hackers Subject: Re: mbuf enhancement patch Date: Tue, 20 Feb 1996 18:59:13 -0800 Lines: 21 Message-ID: <199602210259.SAA04978@Root.COM> NNTP-Posting-Host: seagull.rtd.com Sender: owner-hackers@freebsd.org Precedence: bulk >>>I found the ep driver always keeps some mbuf's in its pool. Is this >>>because mbuf allocation is too expensive for boards which equip small >>>receive buffer? If this is the case, some improvement (not mine :-) is >>>desirable. >> >> I think that's what the author thought, but the FIFO on the 3c509 should be >>sufficiently large enough to not need the extra 1% of speed that having the >>private pool gets you. Our malloc implementation is quite efficient, actually. > >The old 3c509 has 2k bytes RX FIFO. Is this large enough? Yes, but a bit tight. If the driver were properly written, large packets would be put in mbuf clusters which are allocated out of a private pool and should be as fast as the pool that the driver is maintaining. I haven't looked at the driver source in any detail...I've instead decided to rewrite it at some point in the future, but haven't had the time + enough interest yet. -DG David Greenman Core-team/Principal Architect, The FreeBSD Project