3 ms·
I discovered that putting a 10G interface into a bridge implies a very significant slowdown. Linux has to do stuff on the CPU to do the bridging, so that turns
by dale_glass 2y ago
I discovered that putting a 10G interface into a bridge implies a very significant slowdown. Linux has to do stuff on the CPU to do the bridging, so that turns off a large part of the card's acceleration.
That's not a good thing for a server that runs a bunch of VMs.
Fortunately SR-IOV exists, but it seems a tad silly to me that I have to do all this weird PCIe passthrough stuff just for this. It's nice, don't get me wrong, but a bit too exotic for what should be a simple setup.
- toast0 2y agoOh yeah, bridged mode on my little pentium system brings perf way down. It was fine on 1G, but when I upgraded to 10G and wanted to hit numbers, I needed to stop doing software bridging. For me, I have slots and NICs, so I moved away from virtual ethernet on a bridge to actual ports; main host gets the 10G, and everything else gets to use 1G ports. No SR-IOV on my board, but that's ok.
- kjellsbells 2y agoI always found it ironic that virtualization made me have to care about the hardware more than I ever had to before. 2013 me: slap the app on a Dell. It'll be fine. 2017 me: aw crap, the nic doesnt support SR-IOV. What do you mean, I need a special driver? Oh lordy, I'm pinning a whole damn CPU just so DPDK can pull packets off the wire?