From: Paolo Abeni <pab...@redhat.com> Date: Tue, 10 May 2016 22:22:50 +0200
> On Tue, 2016-05-10 at 09:08 -0700, Eric Dumazet wrote: >> On Tue, 2016-05-10 at 18:03 +0200, Paolo Abeni wrote: >> >> > If a single core host is under network flood, i.e. ksoftirqd is >> > scheduled and it eventually (after processing ~640 packets) will let the >> > user space process run. The latter will execute a syscall to receive a >> > packet, which will have to disable/enable bh at least once and that will >> > cause the processing of another ~640 packets. To receive a single packet >> > in user space, the kernel has to process more than one thousand packets. >> >> Looks you found the bug then. Have you tried to fix it ? ... > The ksoftirq and the local_bh_enable() design are the root of the > problem, they need to be touched/affected to solve it. That's not what I read from your description, processing 640 packets before going to ksoftirqd seems to the be the absolute root problem.
