On Thu, 9 Aug 2018 22:15:22 +0200 Daniel Borkmann <dan...@iogearbox.net> wrote:
> On 08/09/2018 03:26 PM, Jesper Dangaard Brouer wrote: > > This implement XDP CPU redirection load-balancing across available > > CPUs, based on the hashing IP-pairs + L4-protocol. This equivalent to > > xdp-cpu-redirect feature in Suricata, which is inspired by the > > Suricata 'ippair' hashing code. > > > > An important property is that the hashing is flow symmetric, meaning > > that if the source and destination gets swapped then the selected CPU > > will remain the same. This is helps locality by placing both directions > > of a flows on the same CPU, in a forwarding/routing scenario. > > > > The hashing INITVAL (15485863 the 10^6th prime number) was fairly > > arbitrary choosen, but experiments with kernel tree pktgen scripts > > (pktgen_sample04_many_flows.sh +pktgen_sample05_flow_per_thread.sh) > > showed this improved the distribution. > > > > This patch also change the default loaded XDP program to be this > > load-balancer. As based on different user feedback, this seems to be > > the expected behavior of the sample xdp_redirect_cpu. > > > > Link: https://github.com/OISF/suricata/commit/796ec08dd7a63 > > Signed-off-by: Jesper Dangaard Brouer <bro...@redhat.com> > > --- > > samples/bpf/xdp_redirect_cpu_kern.c | 103 > > +++++++++++++++++++++++++++++++++++ > > samples/bpf/xdp_redirect_cpu_user.c | 4 + > > 2 files changed, 105 insertions(+), 2 deletions(-) > > > > diff --git a/samples/bpf/xdp_redirect_cpu_kern.c > > b/samples/bpf/xdp_redirect_cpu_kern.c > > index 0cc3d71057f0..a306d1c75622 100644 > > --- a/samples/bpf/xdp_redirect_cpu_kern.c > > +++ b/samples/bpf/xdp_redirect_cpu_kern.c > > @@ -13,6 +13,7 @@ > > > > #include <uapi/linux/bpf.h> > > #include "bpf_helpers.h" > > +#include "hash_func01.h" > > > > #define MAX_CPUS 64 /* WARNING - sync with _user.c */ > > Hmm, this doesn't apply cleanly. I have the following in bpf-next: > > #define MAX_CPUS 12 /* WARNING - sync with _user.c */ > > https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/tree/samples/bpf/xdp_redirect_cpu_kern.c#n17 > > Rebase issue? Please respin, thanks. Ah, this is due to the teardown-fixes patchset for "bpf" git-tree, which you just applied, which changed MAX_CPUS to 64 (so, QA can use the reproducer). -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer
