unruh <un...@invalid.ca> wrote: > This is a rare thing (Ie once in a 100 packets has round trip delay > of 10ms, vs 10us usually.) I have no idea if this is interrupt > coalescing or what. Since our network switched to Gigabit switches > and some of my systems use gigabit cards, the timing behaviour has > become really bad.
> It used to be that I got consistant 140us round trip delays ( with a > scatter of about 10-20us) Now, although that is still the minimum, > all have a scatter of about 50-100us, some have a bivalent round > trip of either around 150us but also around 300 us. Some have a > wildly varying ( a few packets around the 150, most around 300us, > with scatter up to 10ms.) round trip. It is a total mess. It really > seems like the GB switches are a disaster for timing. Of course > running them at 100 would not help. It is a problem with the switch > design I believe. Do you see the issue with classic 100Mbit/s NICs connected to your gigabit switch? Or do you only see the issues with 1 GbE connected systems? If so, then go ahead and disable the interrupt coalescing and see what that changes. Earlier I said that switches wouldn't coalesce - I should say "traditional" (my use of terminology) switches wouldn't - if the "switch" is really a Linux instance running bridging software then... > I have no idea where this horror is taking place-- the NICs, the > switches, .... But you are sure it is gigabit the technology... :-) rick jones -- firebug n, the idiot who tosses a lit cigarette out his car window these opinions are mine, all mine; HP might not want them anyway... :) feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH... _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
