Kok, Auke wrote: > Max Krasnyansky wrote: >> Kok, Auke wrote: >>> Max Krasnyansky wrote: >>>> So you don't think it's related to the interrupt coalescing by any chance ? >>>> I'd suggest to try and disable the coalescing and see if it makes any >>>> difference. >>>> We've had lots of issues with coalescing misbehavior. Not this bad (ie 1 >>>> second) though. >>>> >>>> Add this to modprobe.conf and reload e1000 module >>>> >>>> options e1000 RxIntDelay=0,0 RxAbsIntDelay=0,0 InterruptThrottleRate=0,0 >>>> TxIntDelay=0,0 TxAbsIntDelay=0,0 >>> that can't be the problem. irq moderation would only account for 2-3ms >>> variance >>> maximum. >> Oh, I've definitely seen worse than that. Not as bad as a 1second though. >> Plus you're talking >> about the case when coalescing logic is working as designed ;-). What if >> there is some kind of >> bug where timer did not expire or something. > > we don't use a software timer in e1000 irq coalescing/moderation, it's all in > hardware, so we don't have that problem at all. And I certainly have never > seen > anything you are referring to with e1000 hardware, and I do not know of any > bug > related to this. > > are you maybe confused with other hardware ? > > feel free to demonstrate an example...
Just to give you a background. I wrote and maintain http://libe1000.sf.net So I know E1000 HW and SW in and out. And no I'm not confused with other HW and I know that we're not using SW timers for the coalescing. HW can be buggy as well. Note that I'm not saying that I know for sure that the problem is coalescing, I'm just suggesting to take it out of the equation while Pavel is investigating. Unfortunately I cannot demonstrate an example but I've seen unexplained packet delays in the range of 1-20 milliseconds on E1000 HW (and boy ... I do have a lot of it in my labs). Once coalescing was disabled those problems have gone away. Max -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
