3 ms·
Isn't TCP packet shaping normally done on the network interface these days so you have CPU offloading?
by olavgg 9y ago
Isn't TCP packet shaping normally done on the network interface these days so you have CPU offloading?
- kev009 9y agos/shaping/pacing/, we're trying to smooth out the bursty nature of sending from high speed links and TSO so a flow is less likely to incur large contiguous buffer drops and tail drops along its path rather than limit the flow's throughput. I have a large fleet of intel NICs on the back half of their life cycle. NIC pacers sound good in theory and I'd like to eventually partial offload but they have limitations in terms of flows and number of pacing rates so will still require a software fallback. On a timerwheel, the system overhead for no offload and a partial offload is not nearly economical as theoretical full offload. And contrary to some misinformation from one of the varnish devs in this thread, taking an SWI/context switch/scheduler overhead (these basic concepts will probably get called "babble" by the dude) comprise much of the overhead.