Friendly reminder to test and/or review this patch series presented in the OVS conference talk "Troubleshooting the OVS Data Plane".
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. We believe this is fast enough to not warrant a build- or run-time configuration option to disable this. 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). Jan Scheurich (3) Patch 1/3: Refactor PMD performance into dpif-netdev-perf Patch 2/3: Detailed performance stats for PMDs Patch 3/3: Detection and logging of suspicious PMD iterations 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 lib/automake.mk | 2 + lib/dp-packet.h | 2 + lib/dpif-netdev-perf.c | 512 +++++++++++++++++++++++ lib/dpif-netdev-perf.h | 317 ++++++++++++++ lib/dpif-netdev.c | 479 +++++++++++---------- lib/netdev-dpdk.c | 28 +- lib/netdev-dpdk.h | 14 + ofproto/ofproto-dpif.c | 3 +- tests/pmd.at | 22 +- 9 files changed, 1150 insertions(+), 229 deletions(-) _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
