| Message ID | cover.1618236421.git.grive@u256.net |
|---|---|
| Headers | show |
| Series | dpif-netdev: Parallel offload processing | expand |
Hi Gaetan, On 4/12/21 5:19 PM, Gaetan Rivet wrote: > This patch series aims to improve the performance of the management > of hw-offloads in dpif-netdev. In the current version, some setup > will experience high memory usage and poor latency between a flow > decision and its execution regarding hardware offloading. > > This series starts by measuring key metrics regarding both issues > Those patches are introduced first to compare the current status > with each improvements introduced. > Offloads enqueued and inserted, as well as the latency > from queue insertion to hardware insertion is measured. A new > command 'ovs-appctl dpctl/offload-stats-show' is introduced > to show the current measure. > > In my current performance test setup I am measuring an > average latency hovering between 1~2 seconds. > After the optimizations, it is reduced to 500~900 ms. > Finally when using multiple threads and with proper driver > support[1], it is measured in the order of 1 ms. > > A few modules are introduced: > > * An ID pool with reduced capabilities, simplifying its > operations and allowing better performances in both > single and multi-thread setup. > > * A lockless queue between PMDs / revalidators and > offload thread(s). As the number of PMDs increases, > contention can be high on the shared queue. > This queue is designed to serve as message queue > between threads. > > * A bounded lockless MPMC ring and some helpers for > calculating moving averages. > > * A moving average module for Cumulative and Exponential > moving averages. > > The netdev-offload-dpdk module is made thread-safe. > Internal maps are made per-netdev instead, and locks are > taken for shorter critical sections within the module. > > CI result: https://github.com/grivet/ovs/actions/runs/554918929 > > [1]: The rte_flow API was made thread-safe in the 20.11 DPDK > release. Drivers that do not implement those operations > concurrently are protected by a lock. Others will > allow better concurrency, that improve the result > of this series. > > v2: > > * Improved the MPSC queue API to simplify usage. > > * Moved flush operation from initiator thread to offload > thread(s). This ensures offload metadata are shared only > among the offload thread pool. > > * Flush operation needs additional thread synchronization. > The ovs_barrier currently triggers a UAF. Add a unit-test to > validate its operations and a fix for the UAF. > > CI result: https://github.com/grivet/ovs/actions/runs/741430135 > The error comes from a failure to download 'automake' on > osx, unrelated to any change in this series. > > Gaetan Rivet (28): > netdev: Add flow API uninit function > netdev-offload-dpdk: Use per-netdev offload metadata > netdev-offload-dpdk: Implement hw-offload statistics read > dpctl: Add function to read hardware offload statistics > dpif-netdev: Rename flow offload thread > dpif-netdev: Rename offload thread structure > mov-avg: Add a moving average helper structure > dpif-netdev: Implement hardware offloads stats query > ovs-atomic: Expose atomic exchange operation > mpsc-queue: Module for lock-free message passing > llring: Add lockless MPMC bounded queue structure > seq-pool: Module for faster ID generation > netdev-offload: Add multi-thread API > dpif-netdev: Quiesce offload thread periodically > dpif-netdev: Postpone flow offload item freeing > dpif-netdev: Use seq-pool for mark allocation > dpif-netdev: Introduce tagged union of offload requests > tests: Add ovs-barrier unit test > ovs-thread: Fix barrier use-after-free > dpif-netdev: Execute flush from offload thread > netdev-offload-dpdk: Use per-thread HW offload stats > netdev-offload-dpdk: Lock rte_flow map access > netdev-offload-dpdk: Protect concurrent offload destroy/query > dpif-netdev: Use lockless queue to manage offloads > dpif-netdev: Make megaflow and mark mappings thread objects > dpif-netdev: Replace port mutex by rwlock > dpif-netdev: Use one or more offload threads > netdev-dpdk: Remove rte-flow API access locks > > lib/automake.mk | 7 + > lib/dpctl.c | 36 ++ > lib/dpif-netdev.c | 742 +++++++++++++++++++++++++--------- > lib/dpif-netlink.c | 1 + > lib/dpif-provider.h | 7 + > lib/dpif.c | 8 + > lib/dpif.h | 9 + > lib/llring.c | 153 +++++++ > lib/llring.h | 76 ++++ > lib/mov-avg.h | 171 ++++++++ > lib/mpsc-queue.c | 251 ++++++++++++ > lib/mpsc-queue.h | 189 +++++++++ > lib/netdev-dpdk.c | 6 - > lib/netdev-offload-dpdk.c | 277 +++++++++++-- > lib/netdev-offload-provider.h | 4 + > lib/netdev-offload.c | 92 ++++- > lib/netdev-offload.h | 21 + > lib/ovs-atomic-c++.h | 3 + > lib/ovs-atomic-clang.h | 5 + > lib/ovs-atomic-gcc4+.h | 5 + > lib/ovs-atomic-gcc4.7+.h | 5 + > lib/ovs-atomic-i586.h | 5 + > lib/ovs-atomic-locked.h | 9 + > lib/ovs-atomic-msvc.h | 22 + > lib/ovs-atomic-pthreads.h | 5 + > lib/ovs-atomic-x86_64.h | 5 + > lib/ovs-atomic.h | 8 +- > lib/ovs-thread.c | 61 ++- > lib/ovs-thread.h | 6 +- > lib/seq-pool.c | 198 +++++++++ > lib/seq-pool.h | 66 +++ > tests/automake.mk | 3 + > tests/library.at | 15 + > tests/test-barrier.c | 264 ++++++++++++ > tests/test-mpsc-queue.c | 727 +++++++++++++++++++++++++++++++++ > tests/test-seq-pool.c | 543 +++++++++++++++++++++++++ > vswitchd/vswitch.xml | 16 + > 37 files changed, 3788 insertions(+), 233 deletions(-) > create mode 100644 lib/llring.c > create mode 100644 lib/llring.h > create mode 100644 lib/mov-avg.h > create mode 100644 lib/mpsc-queue.c > create mode 100644 lib/mpsc-queue.h > create mode 100644 lib/seq-pool.c > create mode 100644 lib/seq-pool.h > create mode 100644 tests/test-barrier.c > create mode 100644 tests/test-mpsc-queue.c > create mode 100644 tests/test-seq-pool.c > > -- > 2.31.1 > The series looks almost good to me. Please note that I haven't had a setup to test it this week, I'll try to run some tests with it next week. Thanks, Maxime
On Fri, Apr 23, 2021, at 15:21, Maxime Coquelin wrote: > Hi Gaetan, > > On 4/12/21 5:19 PM, Gaetan Rivet wrote: > > This patch series aims to improve the performance of the management > > of hw-offloads in dpif-netdev. In the current version, some setup > > will experience high memory usage and poor latency between a flow > > decision and its execution regarding hardware offloading. > > > > This series starts by measuring key metrics regarding both issues > > Those patches are introduced first to compare the current status > > with each improvements introduced. > > Offloads enqueued and inserted, as well as the latency > > from queue insertion to hardware insertion is measured. A new > > command 'ovs-appctl dpctl/offload-stats-show' is introduced > > to show the current measure. > > > > In my current performance test setup I am measuring an > > average latency hovering between 1~2 seconds. > > After the optimizations, it is reduced to 500~900 ms. > > Finally when using multiple threads and with proper driver > > support[1], it is measured in the order of 1 ms. > > > > A few modules are introduced: > > > > * An ID pool with reduced capabilities, simplifying its > > operations and allowing better performances in both > > single and multi-thread setup. > > > > * A lockless queue between PMDs / revalidators and > > offload thread(s). As the number of PMDs increases, > > contention can be high on the shared queue. > > This queue is designed to serve as message queue > > between threads. > > > > * A bounded lockless MPMC ring and some helpers for > > calculating moving averages. > > > > * A moving average module for Cumulative and Exponential > > moving averages. > > > > The netdev-offload-dpdk module is made thread-safe. > > Internal maps are made per-netdev instead, and locks are > > taken for shorter critical sections within the module. > > > > CI result: https://github.com/grivet/ovs/actions/runs/554918929 > > > > [1]: The rte_flow API was made thread-safe in the 20.11 DPDK > > release. Drivers that do not implement those operations > > concurrently are protected by a lock. Others will > > allow better concurrency, that improve the result > > of this series. > > > > v2: > > > > * Improved the MPSC queue API to simplify usage. > > > > * Moved flush operation from initiator thread to offload > > thread(s). This ensures offload metadata are shared only > > among the offload thread pool. > > > > * Flush operation needs additional thread synchronization. > > The ovs_barrier currently triggers a UAF. Add a unit-test to > > validate its operations and a fix for the UAF. > > > > CI result: https://github.com/grivet/ovs/actions/runs/741430135 > > The error comes from a failure to download 'automake' on > > osx, unrelated to any change in this series. > > > > Gaetan Rivet (28): > > netdev: Add flow API uninit function > > netdev-offload-dpdk: Use per-netdev offload metadata > > netdev-offload-dpdk: Implement hw-offload statistics read > > dpctl: Add function to read hardware offload statistics > > dpif-netdev: Rename flow offload thread > > dpif-netdev: Rename offload thread structure > > mov-avg: Add a moving average helper structure > > dpif-netdev: Implement hardware offloads stats query > > ovs-atomic: Expose atomic exchange operation > > mpsc-queue: Module for lock-free message passing > > llring: Add lockless MPMC bounded queue structure > > seq-pool: Module for faster ID generation > > netdev-offload: Add multi-thread API > > dpif-netdev: Quiesce offload thread periodically > > dpif-netdev: Postpone flow offload item freeing > > dpif-netdev: Use seq-pool for mark allocation > > dpif-netdev: Introduce tagged union of offload requests > > tests: Add ovs-barrier unit test > > ovs-thread: Fix barrier use-after-free > > dpif-netdev: Execute flush from offload thread > > netdev-offload-dpdk: Use per-thread HW offload stats > > netdev-offload-dpdk: Lock rte_flow map access > > netdev-offload-dpdk: Protect concurrent offload destroy/query > > dpif-netdev: Use lockless queue to manage offloads > > dpif-netdev: Make megaflow and mark mappings thread objects > > dpif-netdev: Replace port mutex by rwlock > > dpif-netdev: Use one or more offload threads > > netdev-dpdk: Remove rte-flow API access locks > > > > lib/automake.mk | 7 + > > lib/dpctl.c | 36 ++ > > lib/dpif-netdev.c | 742 +++++++++++++++++++++++++--------- > > lib/dpif-netlink.c | 1 + > > lib/dpif-provider.h | 7 + > > lib/dpif.c | 8 + > > lib/dpif.h | 9 + > > lib/llring.c | 153 +++++++ > > lib/llring.h | 76 ++++ > > lib/mov-avg.h | 171 ++++++++ > > lib/mpsc-queue.c | 251 ++++++++++++ > > lib/mpsc-queue.h | 189 +++++++++ > > lib/netdev-dpdk.c | 6 - > > lib/netdev-offload-dpdk.c | 277 +++++++++++-- > > lib/netdev-offload-provider.h | 4 + > > lib/netdev-offload.c | 92 ++++- > > lib/netdev-offload.h | 21 + > > lib/ovs-atomic-c++.h | 3 + > > lib/ovs-atomic-clang.h | 5 + > > lib/ovs-atomic-gcc4+.h | 5 + > > lib/ovs-atomic-gcc4.7+.h | 5 + > > lib/ovs-atomic-i586.h | 5 + > > lib/ovs-atomic-locked.h | 9 + > > lib/ovs-atomic-msvc.h | 22 + > > lib/ovs-atomic-pthreads.h | 5 + > > lib/ovs-atomic-x86_64.h | 5 + > > lib/ovs-atomic.h | 8 +- > > lib/ovs-thread.c | 61 ++- > > lib/ovs-thread.h | 6 +- > > lib/seq-pool.c | 198 +++++++++ > > lib/seq-pool.h | 66 +++ > > tests/automake.mk | 3 + > > tests/library.at | 15 + > > tests/test-barrier.c | 264 ++++++++++++ > > tests/test-mpsc-queue.c | 727 +++++++++++++++++++++++++++++++++ > > tests/test-seq-pool.c | 543 +++++++++++++++++++++++++ > > vswitchd/vswitch.xml | 16 + > > 37 files changed, 3788 insertions(+), 233 deletions(-) > > create mode 100644 lib/llring.c > > create mode 100644 lib/llring.h > > create mode 100644 lib/mov-avg.h > > create mode 100644 lib/mpsc-queue.c > > create mode 100644 lib/mpsc-queue.h > > create mode 100644 lib/seq-pool.c > > create mode 100644 lib/seq-pool.h > > create mode 100644 tests/test-barrier.c > > create mode 100644 tests/test-mpsc-queue.c > > create mode 100644 tests/test-seq-pool.c > > > > -- > > 2.31.1 > > > > The series looks almost good to me. > Please note that I haven't had a setup to test it this week, I'll try to > run some tests with it next week. > > Thanks, > Maxime > > Thank you Maxime, I've made the modifications to the RCU quiescing, as well as moved the two fixes from this series (flow offload thread renaming, ovs-barrier UAF) first to ensure backporting would be easy if needed. In tests, it seems using ovsrcu_quiesce() actually improved latency, so I decided to send the v3 so you would see the correct numbers in your tests. v3 is here: https://patchwork.ozlabs.org/project/openvswitch/list/?series=240678 Cheers,
This patch series aims to improve the performance of the management of hw-offloads in dpif-netdev. In the current version, some setup will experience high memory usage and poor latency between a flow decision and its execution regarding hardware offloading. This series starts by measuring key metrics regarding both issues Those patches are introduced first to compare the current status with each improvements introduced. Offloads enqueued and inserted, as well as the latency from queue insertion to hardware insertion is measured. A new command 'ovs-appctl dpctl/offload-stats-show' is introduced to show the current measure. In my current performance test setup I am measuring an average latency hovering between 1~2 seconds. After the optimizations, it is reduced to 500~900 ms. Finally when using multiple threads and with proper driver support[1], it is measured in the order of 1 ms. A few modules are introduced: * An ID pool with reduced capabilities, simplifying its operations and allowing better performances in both single and multi-thread setup. * A lockless queue between PMDs / revalidators and offload thread(s). As the number of PMDs increases, contention can be high on the shared queue. This queue is designed to serve as message queue between threads. * A bounded lockless MPMC ring and some helpers for calculating moving averages. * A moving average module for Cumulative and Exponential moving averages. The netdev-offload-dpdk module is made thread-safe. Internal maps are made per-netdev instead, and locks are taken for shorter critical sections within the module. CI result: https://github.com/grivet/ovs/actions/runs/554918929 [1]: The rte_flow API was made thread-safe in the 20.11 DPDK release. Drivers that do not implement those operations concurrently are protected by a lock. Others will allow better concurrency, that improve the result of this series. v2: * Improved the MPSC queue API to simplify usage. * Moved flush operation from initiator thread to offload thread(s). This ensures offload metadata are shared only among the offload thread pool. * Flush operation needs additional thread synchronization. The ovs_barrier currently triggers a UAF. Add a unit-test to validate its operations and a fix for the UAF. CI result: https://github.com/grivet/ovs/actions/runs/741430135 The error comes from a failure to download 'automake' on osx, unrelated to any change in this series. Gaetan Rivet (28): netdev: Add flow API uninit function netdev-offload-dpdk: Use per-netdev offload metadata netdev-offload-dpdk: Implement hw-offload statistics read dpctl: Add function to read hardware offload statistics dpif-netdev: Rename flow offload thread dpif-netdev: Rename offload thread structure mov-avg: Add a moving average helper structure dpif-netdev: Implement hardware offloads stats query ovs-atomic: Expose atomic exchange operation mpsc-queue: Module for lock-free message passing llring: Add lockless MPMC bounded queue structure seq-pool: Module for faster ID generation netdev-offload: Add multi-thread API dpif-netdev: Quiesce offload thread periodically dpif-netdev: Postpone flow offload item freeing dpif-netdev: Use seq-pool for mark allocation dpif-netdev: Introduce tagged union of offload requests tests: Add ovs-barrier unit test ovs-thread: Fix barrier use-after-free dpif-netdev: Execute flush from offload thread netdev-offload-dpdk: Use per-thread HW offload stats netdev-offload-dpdk: Lock rte_flow map access netdev-offload-dpdk: Protect concurrent offload destroy/query dpif-netdev: Use lockless queue to manage offloads dpif-netdev: Make megaflow and mark mappings thread objects dpif-netdev: Replace port mutex by rwlock dpif-netdev: Use one or more offload threads netdev-dpdk: Remove rte-flow API access locks lib/automake.mk | 7 + lib/dpctl.c | 36 ++ lib/dpif-netdev.c | 742 +++++++++++++++++++++++++--------- lib/dpif-netlink.c | 1 + lib/dpif-provider.h | 7 + lib/dpif.c | 8 + lib/dpif.h | 9 + lib/llring.c | 153 +++++++ lib/llring.h | 76 ++++ lib/mov-avg.h | 171 ++++++++ lib/mpsc-queue.c | 251 ++++++++++++ lib/mpsc-queue.h | 189 +++++++++ lib/netdev-dpdk.c | 6 - lib/netdev-offload-dpdk.c | 277 +++++++++++-- lib/netdev-offload-provider.h | 4 + lib/netdev-offload.c | 92 ++++- lib/netdev-offload.h | 21 + lib/ovs-atomic-c++.h | 3 + lib/ovs-atomic-clang.h | 5 + lib/ovs-atomic-gcc4+.h | 5 + lib/ovs-atomic-gcc4.7+.h | 5 + lib/ovs-atomic-i586.h | 5 + lib/ovs-atomic-locked.h | 9 + lib/ovs-atomic-msvc.h | 22 + lib/ovs-atomic-pthreads.h | 5 + lib/ovs-atomic-x86_64.h | 5 + lib/ovs-atomic.h | 8 +- lib/ovs-thread.c | 61 ++- lib/ovs-thread.h | 6 +- lib/seq-pool.c | 198 +++++++++ lib/seq-pool.h | 66 +++ tests/automake.mk | 3 + tests/library.at | 15 + tests/test-barrier.c | 264 ++++++++++++ tests/test-mpsc-queue.c | 727 +++++++++++++++++++++++++++++++++ tests/test-seq-pool.c | 543 +++++++++++++++++++++++++ vswitchd/vswitch.xml | 16 + 37 files changed, 3788 insertions(+), 233 deletions(-) create mode 100644 lib/llring.c create mode 100644 lib/llring.h create mode 100644 lib/mov-avg.h create mode 100644 lib/mpsc-queue.c create mode 100644 lib/mpsc-queue.h create mode 100644 lib/seq-pool.c create mode 100644 lib/seq-pool.h create mode 100644 tests/test-barrier.c create mode 100644 tests/test-mpsc-queue.c create mode 100644 tests/test-seq-pool.c -- 2.31.1