Date: Thu, 27 Sep 2001 12:24:10 -0400 (EDT) From: Andrew Gallatin <gallatin@cs.duke.edu> To: Ronald G Minnich <rminnich@lanl.gov> Cc: "Louis A. Mamakos" <louie@TransSys.COM>, <hackers@FreeBSD.ORG> Subject: Re: TCP&IP cksum offload on FreeBSD 4.2 Message-ID: <15283.21162.173735.343154@grasshopper.cs.duke.edu> In-Reply-To: <Pine.LNX.4.33.0109271009300.27057-100000@snaresland.acl.lanl.gov> References: <15283.19536.410864.339942@grasshopper.cs.duke.edu> <Pine.LNX.4.33.0109271009300.27057-100000@snaresland.acl.lanl.gov>
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Ronald G Minnich writes: > On Thu, 27 Sep 2001, Andrew Gallatin wrote: > > > At this level, you're basically screwed. A sofware checksum isn't > > even an option on other PCI users, like disk controllers. If you > > don't trust your PCI chipset, what do you do about things like that? > > > > I'm rather curious -- what was the problematic hardware combination? > > Can't say yet :-( > > But it is one of the fancy network interfaces that essentially runs an > RTOS on the NIC so it can "help you". Actually fancy $5000 network > interfaces are in general less reliable than your average garden-variety > $2 IDE chip. Partly because they have so much capability. > > So we don't worry a lot about lossage with IDE. But it's a big problem on > expensive, high end, high performance network interfaces. But SCSI isn't immune either. We had some data corruption problems with early adaptec Ultra-2 scsi controllers too, before Justin fixed it by working around it in the driver. Basically, anything that uses a PCI chipset harder or in different ways than its designers expected can end up being a problem. Low volume hardware is somtimes worse, but not always... Drew To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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