On Tue, 2013-07-02 at 13:18 -0600, Jason Gunthorpe wrote: > On Mon, Jul 01, 2013 at 07:26:05AM -0400, David Dillow wrote: > > You assume independent failures, which is suspect -- many times these > > are data-dependent, or so I tend to think. Jason, do you have any > > insight on this (overall) topic you could share? > > All data transmitted on modern serial links is 'whitened' > somehow. This is does independently on a link-by-link basis either > with 8b/10b coding or with the 64b/66b scrambler. So the idea of a > high level 'magic packet' that causes data-dependent errors is not > statistically likely.
My thought was that if we hit a statistically unlikely pattern that caused an issue, the retransmission is likely to also hit the issue given the deterministic scrambling. But I didn't think about the fact that the signal stream was being whitened. > It is best to use all the information the SM provides when setting up > the path, however I don't think there is a best practice idea yet for > how to setup the retry count though.. Hmm, that would be a useful presentation for the workshop; I'll have to see if I can get some people interested here. Thanks for the information, Dave -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
