The run-time performance of PMDs is often difficult to understand and trouble-shoot. The existing PMD statistics counters only provide a coarse grained average picture. At packet rates of several Mpps sporadic drops of packet bursts happen at sub-millisecond time scales and are impossible to capture and analyze with existing tools.
This patch set refactors the existing PMD statistics into a dedicated submodule and collects a large number of important PMD performance metrics per PMD iteration, maintaining histograms and circular histories for iteration metrics and millisecond averages. To capture sporadic drop events, the patch set can be configured to monitor iterations for suspicious metrics and to log the neighborhood of such iterations for off-line analysis. The extra cost for the performance metric collection and the supervision has been measured to be in the order of 1% compared to the base commit in a PVP setup with L3 pipeline over VXLAN tunnels. For that reason the metrics collection is disabled by default and can be enabled at run-time through configuration. The first patch in the series fully includes the changes proposed in Darrel's earlier "[patch_v5 0/3] dpif-netdev: Fix and refactor pmd stats" (https://mail.openvswitch.org/pipermail/ovs-dev/2017-August/337686.html). v3->v4: Rebased to master (commit 4d0a31b) Reverting changes to struct dp_netdev_pmd_thread Make metrics collection configurable Several bugfixes v2->v3: Rebased to OVS master (commit 3728b3b) Non-trivial adaptation to struct dp_netdev_pmd_thread refactored in commit a807c157 (Bhanu) No other changes compared to v2 v1 -> v2: Rebased to OVS master (commit 7468ec788) No other changes compared to v1 Jan Scheurich (3): dpif-netdev: Refactor PMD performance into dpif-netdev-perf dpif-netdev: Detailed performance stats for PMDs dpif-netdev: Detection and logging of suspicious PMD iterations lib/automake.mk | 2 + lib/dp-packet.h | 2 + lib/dpif-netdev-perf.c | 515 +++++++++++++++++++++++++++++++++++++++++++++++++ lib/dpif-netdev-perf.h | 322 +++++++++++++++++++++++++++++++ lib/dpif-netdev.c | 471 ++++++++++++++++++++++++++------------------ lib/netdev-dpdk.c | 23 ++- lib/netdev-dpdk.h | 14 ++ ofproto/ofproto-dpif.c | 3 +- tests/pmd.at | 22 ++- 9 files changed, 1168 insertions(+), 206 deletions(-) create mode 100644 lib/dpif-netdev-perf.c create mode 100644 lib/dpif-netdev-perf.h -- 1.9.1 _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
