On Wed, Aug 31, 2011 at 7:58 PM, Adam Carter <[email protected]> wrote: >> I just might have an opportunity to setup a Gentoo >> System using 10 G ethernet (fiber). The .39 >> kernel lists this hardware [1]. >> >> Does anyone have any experience with this hardware? >> Does it work? Did you make any bandwidth measurements? >> What type of fiber (mulimode/singlemode) (ST/SC) did you >> use? >> >> Any comments? Is the kernel a bottleneck or your application? > > Intel are active in linux kernel development and their linux drivers > seem to be very good. > > When testing Intel copper gig interfaces on an intel firewall (HP > DL380G5 8 core box), I was able to send a core to 100% with ~330Mb of > small packets. The limiting factor appears to be packet rate, and the > consequent processing of interrupts (1 irq to 1 core). I don't think > that a 10Gig interface would pass any more than that due to similar > limitations. > > Tweaking the e1000 driver options RxDescriptors, TxDescriptors and > RxIntDelay pushed it up to ~350Mb. MSI was enabled so no interrupt > sharing. > > So if you're running normal sized packets, you should be ok. Otherwise > you way want to look at what irqbalance can do for you (I didn't try > it at the time). > > Also don't forget stuff like Large Receive Offload in your kernel.
I've overheard IRC conversations that discussed multi-queue network cards in the context of multi-core systems. My educated guess, based on what you mention, is that each queue in the card would ping a different interrupt. Each interrupt might be handled by a different core, so you'd see a scaleable improvement there. -- :wq
