Date: Wed, 3 Mar 2004 09:45:24 -0800 From: Luigi Rizzo <rizzo@icir.org> To: Andrew Gallatin <gallatin@cs.duke.edu> Cc: freebsd-hackers@freebsd.org Subject: Re: em0, polling performance, P4 2.8ghz FSB 800mhz Message-ID: <20040303094524.A26257@xorpc.icir.org> In-Reply-To: <16453.62383.59435.72390@grasshopper.cs.duke.edu>; from gallatin@cs.duke.edu on Wed, Mar 03, 2004 at 10:03:11AM -0500 References: <FE045D4D9F7AED4CBFF1B3B813C85337045D832C@mail.sandvine.com> <16453.62383.59435.72390@grasshopper.cs.duke.edu>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, Mar 03, 2004 at 10:03:11AM -0500, Andrew Gallatin wrote: > > Don Bowman writes: > > > I'm not sure what affect on fxp. fxp is inherently limited > > by something internal to it, which prevents achieving > > high packet rates. bge is the best chip, but doesn't but you should not compare apples and oranges. the fxp is a 100mbit NIC, the bge is a GigE NIC. > Just curious - why is bge the best chip? Is it because > it exports a really nice API (separate recv ring for small messages), > or is the chip inherently faster, regardless of its API? > > I'm trying to design a new ethernet API for a firmware-based nic, > and I'm trying to convince a colleague that having separate > receive rings for small and large frames is a really good thing. i am actually not very convinced either, unless you are telling me that there is a way to preserve ordering. Or you'd be in trouble when, on your busy link, there is a mismatch between user-level and link-level block sizes. So, what is your design like, you want to pass the NIC buffers of 2-3 different sizes and let the NIC choose from the most appropriate pool depending on the incoming frame size, but still return received frames in a single ring in arrival order ? This would make sense, but having completely separate rings (small frames here, large frames there) with no ordering relation would not. cheers luigi > Drew > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org"
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20040303094524.A26257>