On 18.5.2022. 17:31, Alexander Bluhm wrote: > Hi, > > For parallel IP forwarding I had put kernel lock around arpresolve() > as a quick workaround for crashes. Moving the kernel lock inside > the function makes the hot path lock free. I see slight prerformace > increase in my test and no lock contention in kstack flamegraph. > > http://bluhm.genua.de/perform/results/latest/2022-05-16T00%3A00%3A00Z/btrace/tcpbench_-S1000000_-t10_-n100_10.3.45.35-btrace-kstack.0.svg > http://bluhm.genua.de/perform/results/latest/patch-sys-arpresolve-kernel-lock.1/btrace/tcpbench_-S1000000_-t10_-n100_10.3.45.35-btrace-kstack.0.svg > > Search for kernel_lock. Matched goes from 0.6% to 0.2% > > We are running such a diff in our genua code for a while. I think > route flags need more love. I doubt that all flags and fields are > consistent when run on multiple CPU. But this diff does not make > it worse and increases MP pressure.
Hi, I'm running this diff on messy network with lots of "arp: attempt to add entry" and sometimes "arpresolve: XXX: route contains no arp information" logs and everything seems fine ..
