Michal Zalewski <lcamtufat_private> wrote: > Try the same via loopback device - should not work. I believe this is not > Linux kernel UDP handling problem. It might be, as suggested, but > something between hardware and software, instead (like "IRQ congestion"), > and probably should work for everything - TCP, ICMP? At the last Linux Kernel Summit, Jamal Hadi Salim had a proposal for speeding up packet handling in the 2.5 kernel. The issue is currently that each packet coming into a network interface triggers an interrupt. It's the interrupt servicing overhead that is slowing the machine. The proposal for 2.5 was to disable interrupts on an interface after the first packet, and use other methods for noticing and grabbing the later packets. There are other operating systems (QNX, etc) that do this already. Jamal's tests showed that removing this overhead drastically sped up the network response, and removed much of the CPU overhead. > Of course I can be wrong - all I say is that I was not able to > reproduce this behavior in my test network, maybe because it is 10 > Mbit, Implementations which appear to work under small loads may not scale to higher loads. Alan DeKok.
This archive was generated by hypermail 2b30 : Fri Jul 27 2001 - 12:47:35 PDT