From: Alexei Starovoitov Date: Fri, 26 Jul 2019 01:00:51 +0000 (-0700) Subject: Merge branch 'flow_dissector-input-flags' X-Git-Tag: Ubuntu-5.13.0-19.19~7681^2~248^2~18 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=943e398dd36c2f50ab5828e6ce502a16d4bad4db;p=mirror_ubuntu-jammy-kernel.git Merge branch 'flow_dissector-input-flags' Stanislav Fomichev says: ==================== C flow dissector supports input flags that tell it to customize parsing by either stopping early or trying to parse as deep as possible. BPF flow dissector always parses as deep as possible which is sub-optimal. Pass input flags to the BPF flow dissector as well so it can make the same decisions. Series outline: * remove unused FLOW_DISSECTOR_F_STOP_AT_L3 flag * export FLOW_DISSECTOR_F_XXX flags as uapi and pass them to BPF flow dissector * add documentation for the export flags * support input flags in BPF_PROG_TEST_RUN via ctx_{in,out} * sync uapi to tools * support FLOW_DISSECTOR_F_PARSE_1ST_FRAG in selftest * support FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL in kernel and selftest * support FLOW_DISSECTOR_F_STOP_AT_ENCAP in selftest Pros: * makes BPF flow dissector faster by avoiding burning extra cycles * existing BPF progs continue to work by ignoring the flags and always parsing as deep as possible Cons: * new UAPI which we need to support (OTOH, if we need to deprecate some flags, we can just stop setting them upon calling BPF programs) Some numbers (with .repeat = 4000000 in test_flow_dissector): test_flow_dissector:PASS:ipv4-frag 35 nsec test_flow_dissector:PASS:ipv4-frag 35 nsec test_flow_dissector:PASS:ipv4-no-frag 32 nsec test_flow_dissector:PASS:ipv4-no-frag 32 nsec test_flow_dissector:PASS:ipv6-frag 39 nsec test_flow_dissector:PASS:ipv6-frag 39 nsec test_flow_dissector:PASS:ipv6-no-frag 36 nsec test_flow_dissector:PASS:ipv6-no-frag 36 nsec test_flow_dissector:PASS:ipv6-flow-label 36 nsec test_flow_dissector:PASS:ipv6-flow-label 36 nsec test_flow_dissector:PASS:ipv6-no-flow-label 33 nsec test_flow_dissector:PASS:ipv6-no-flow-label 33 nsec test_flow_dissector:PASS:ipip-encap 38 nsec test_flow_dissector:PASS:ipip-encap 38 nsec test_flow_dissector:PASS:ipip-no-encap 32 nsec test_flow_dissector:PASS:ipip-no-encap 32 nsec The improvement is around 10%, but it's in a tight cache-hot BPF_PROG_TEST_RUN loop. ==================== Signed-off-by: Alexei Starovoitov --- 943e398dd36c2f50ab5828e6ce502a16d4bad4db