From patchwork Sat Jan 12 20:37:46 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Lam, Tiago" X-Patchwork-Id: 1023974 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=openvswitch.org (client-ip=140.211.169.12; helo=mail.linuxfoundation.org; envelope-from=ovs-dev-bounces@openvswitch.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=intel.com Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 43cWzb6MqNz9s3q for ; Sun, 13 Jan 2019 07:48:42 +1100 (AEDT) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 4EA5D241C; Sat, 12 Jan 2019 20:48:38 +0000 (UTC) X-Original-To: ovs-dev@openvswitch.org Delivered-To: ovs-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id DEAAF23F8 for ; Sat, 12 Jan 2019 20:38:06 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 4558E710 for ; Sat, 12 Jan 2019 20:38:05 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Jan 2019 12:38:04 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,470,1539673200"; d="scan'208";a="109394865" Received: from silpixa00399125.ir.intel.com ([10.237.223.34]) by orsmga008.jf.intel.com with ESMTP; 12 Jan 2019 12:38:01 -0800 From: Tiago Lam To: ovs-dev@openvswitch.org Date: Sat, 12 Jan 2019 20:37:46 +0000 Message-Id: <1547325477-207468-1-git-send-email-tiago.lam@intel.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: fbl@sysclose.org, i.maximets@samsung.com Subject: [ovs-dev] [PATCH v14 00/11] Support multi-segment mbufs X-BeenThere: ovs-dev@openvswitch.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: ovs-dev-bounces@openvswitch.org Errors-To: ovs-dev-bounces@openvswitch.org Overview ======== This patchset introduces support for multi-segment mbufs to OvS-DPDK. Multi-segment mbufs are typically used when the size of an mbuf is insufficient to contain the entirety of a packet's data. Instead, the data is split across numerous mbufs, each carrying a portion, or 'segment', of the packet data. Mbufs are chained via their 'next' attribute (an mbuf pointer). The main motivation behind the support for multi-segment mbufs is to later introduce TSO (use case i. below) / GRO in OvS-DPDK, which is planned to be introduced after this series. Use Cases ========= i. Handling oversized (guest-originated) frames, which are marked for hardware accelration/offload (TSO, for example). Packets which originate from a non-DPDK source may be marked for offload; as such, they may be larger than the permitted ingress interface's MTU, and may be stored in an oversized dp-packet. In order to transmit such packets over a DPDK port, their contents must be copied to a DPDK mbuf (via dpdk_do_tx_copy). However, in its current implementation, that function only copies data into a single mbuf; if the space available in the mbuf is exhausted, but not all packet data has been copied, then it is lost. Similarly, when cloning a DPDK mbuf, it must be considered whether that mbuf contains multiple segments. Both issues are resolved within this patchset. ii. Handling jumbo frames. While OvS already supports jumbo frames, it does so by increasing mbuf size, such that the entirety of a jumbo frame may be handled in a single mbuf. This is certainly the preferred, and most performant approach (and remains the default). Enabling multi-segment mbufs ============================ Multi-segment and single-segment mbufs are mutually exclusive, and the user must decide on which approach to adopt on init. The introduction of a new OVSDB field, 'dpdk-multi-seg-mbufs', facilitates this. This is a global boolean value, which determines how jumbo frames are represented across all DPDK ports. In the absence of a user-supplied value, 'dpdk-multi-seg-mbufs' defaults to false, i.e. multi-segment mbufs must be explicitly enabled / single-segment mbufs remain the default. Setting the field is identical to setting existing DPDK-specific OVSDB fields: ovs-vsctl set Open_vSwitch . other_config:dpdk-init=true ovs-vsctl set Open_vSwitch . other_config:dpdk-lcore-mask=0x10 ovs-vsctl set Open_vSwitch . other_config:dpdk-socket-mem=4096,0 ==> ovs-vsctl set Open_vSwitch . other_config:dpdk-multi-seg-mbufs=true Performance notes (based on v8, 1st non-RFC) ================= In order to test for regressions in performance, tests were run on top of master 88125d6 and v8 of this patchset, both with the multi-segment mbufs option enabled and disabled. VSperf was used to run the phy2phy_cont and pvp_cont tests with varying packet sizes of 64B, 1500B and 7000B, on a 10Gbps interface. Test | Size | Master | Multi-seg disabled | Multi-seg enabled ------------------------------------------------------------- p2p | 64 | ~22.7 | ~22.65 | ~18.3 p2p | 1500 | ~1.6 | ~1.6 | ~1.6 p2p | 7000 | ~0.36 | ~0.36 | ~0.36 pvp | 64 | ~6.7 | ~6.7 | ~6.3 pvp | 1500 | ~1.6 | ~1.6 | ~1.6 pvp | 7000 | ~0.36 | ~0.36 | ~0.36 Packet size is in bytes, while all packet rates are reported in mpps (aggregated). No noticeable regression has been observed (certainly everything is within the ± 5% margin of existing performance), aside from the 64B packet size case when multi-segment mbuf is enabled. This is expected, however, because of how Tx vectoriszed functions are incompatible with multi-segment mbufs on some PMDs. The PMD under use during these tests was the i40e (on a Intel X710 NIC), which indeed doesn't support vectorized Tx functions with multi-segment mbufs. --- v14: - Rebase on master adb3f0b ("python: Avoid flake8 warning for unused variables."); - Reorder changes to dp_packet_l2_5/l3/l4() from patch 06/11 to patch 03/11 (Ian Stokes); - Fix non-null warning in GCC 8.2.1 (06/11, David Merchant); - Linearize packet in process_one() only, when entering Userspace Conntrack (06/11, Darrell Ball); - Change dp_packet_linearize() logic to be aware if a packet is linear and bail out early if so (06/11, Darrell Ball); - Add function header comments to new functions introduced in lib/packets.c (06/11, Darrell Ball); - Fix leakeage in dp_packet_linearize() when calling rte_pktmbuf_read(), if error occurs (06/11, Ilya Maximets); - Return miniflow_extract() error in flow_extract() and check error in callers, appropriately (06/11, Ilya Maximets). v13: - Fix patch 05/11, which was missing the copy of the mbufs flags in dp_packet_copy_mbuf_flags(); - Re-order changes in dp_packet_copy_mbuf_flags() back to patch 05/11, instead of being done later in patch 06/11. v12: - Rebase on master 46df7fa ("netdev-tc-offloads: Support IPv6 hlimit rewrite"); - Previous patchset v11 took the approach of modifying the dp_packet_l2_5/l3/l4() functions so the size of the header to be fetched would be passed by the caller. This, however, would mean that many places throughout the code base would need to be modified. Instead, v12 takes the approach of, when multi-segments is enabled, verifying that incoming packets have their respective headers in the first mbuf. This is done in miniflow_extract(), which now may return an error; - Now that we have moved to DPDK 18.11, where more devices are reporting their offload capabilities, check for the DEV_TX_OFFLOAD_MULTI_SEGS offload capability before setting it; - Add comment to dp_packet_set_size() in dp-packet.h, to clarify its behaviour (Ian Stokes); - Fix coding style in several comments (Ian Stokes). v11: - Rebase on master 35fe9ef ("dpif-netdev: Add vlan to mask for flow_put operation."); - Address Flavio's comments: - Remove unneeded RTE_PKTMBUF_HEADROOM used to extend an mbufs' data room when calling rte_pktmbuf_pool_create(); - Remove MIN() condition in __packet_set_data() as the condition could never go above the packet's size; - Move dp_packet_copy_mbuf_flags() to the header file and fix a leak when calling dp_packet_clone_with_headroom(); - Remove condition from dp_packet_linearize(). Callers must ensure the packet is non-linear before calling this function; - Add new dp_packet_read_data() which enables callers to get a specific portion of a dp_packet's data, copied only as last resort; - Address Ilya's comments: - Fix failing STP tests; - Improve dp_packet_equal() to consider packets identical in data but different in mbuf layout; - New packet_csum() and packet_crc32c() now provide a new way to calculate the checksum and crc32 of a dp_packet, by taking advantage of the newly introduced dp_packet_read_data(); - Move the code base, where appropriate, to use the new packet_csum() and packet_crc32c() APIs where appropriate. v10: - Rebase on master 0d5450a ("ovsdb-client: Fix a bug that uses wrong index"); - Address Ilya's comments: - Fix dp_packet_reset() to not trim the packet; - Remove unused netdev_dpdk_is_multi_segment_mbufs_enabled() function; - Modify the dp_packet_l[2_5|3|4] layer functions to check that enough data is present in the packet before returning. The callers were also modified to act accordingly. - Add comment to dp_packet_set_size() to clarify its usage and modify dp_packet_pull() to comply with that; - Modified slightly the "linearization" approach. Instead of making it an implict operation there are now two functions, dp_packet_is_linear() and dp_packet_linearize(), that enable the callers to explicity check if a packet needs linearization and linearize it if needed; - Briefly mention the Userspace Conntrack as one of the "limitations" when using multi-segment mbufs. v9: - Rebase on master e4e2009 ("tunnel, tests: Sort flow output in ERSPAN v1/v2 metadata"); - Simplify patch 09/14. The functions introduced in packets.c were dropped so the code in netdev-native-tnl.c remains largely the same. These can be introduced at a later time, if needed (maybe when csum across segmented data is introduced); v8: - Rebase on master 1dd218a ("ovsdb-idl: Fix recently introduced Python 3 tests."); - Address Ian's comment: - Fix sparse warnings on patch 07/14 and 12/14 by allocating memory dynamically. - Address Ilya's comments: - netdev_linux_tap_batch_send() and udp_extract_tnl_md() now linearize the data before hand, beforing write()'ing or performing the checksums in the data; - Some other cases have been found and adapted; The new patch 09/14 introduced in the series is where the "linearization" logic is introduced and, as a consequence, some users of the dp_packet API, which were assuming the data is held contiguously in memory, are changed to use the new APIs. - Add support for multi-segment mbufs to dp_packet_equal() (patch 06/14); - Fix a bug in patch 08/14 where the call to dp_packet_copy_mbuf_flags() in dp_packet_clone_with_headroom() was setting incorrectly the nb_segs field on the destination mbuf; - Add unit-tests for dp_packet_equal() and (new) dp_packet_linear_data() to patch 12/14; - Add a comment to jumbo-frames.rst under topics/dpdk/ to warn how multi-segments mbufs may affect performance when using large packets across DPDK and non-DPDK ports. v7: - Rebase on master 024810c ("Prepare for post-2.10.0 (2.10.90)."); - Add Ben's proposed fix for automake's warning; - Add a note to cover letter to explain this is preperatory work for TSO / GRO. v6: - Rebase on master d1b235d ("tests: Add test for ovn-nbctl's command parser error paths."); - Address Darrell's comments: - The changes in dp_packet_resize__() were trying to alleviate the call to OVS_NOT_REACHED() for DPDK packets, by trying to reuse the available tailroom space when no more headroom space is available, and vice-versa. However, this was breaking the API for the dp_packet_resize__() function (only called in dp_packet_prealloc_tailroom() and dp_packet_prealloc_headroom()), which doesn't seem to suit the purposes for DPDK packets. Instead, and because this is isolate funtionality, revert to the previous state where dp_packet_resize__() is not supported for DPDK packets. Hence, then patch 08/14 has been dropped. - Additionally, fix the tests that were relying on the removed functionality. v5: - Rebase on master 030958a0cc ("conntrack: Fix conn_update_state_alg use after free."); - Address Eelco's comments: - Remove dpdk_mp_sweep() call in netdev_dpdk_mempool_configure(), a leftover from rebase. Only call should be in dpdk_mp_get(); - Remove NEWS line added by mistake during rebase (about adding experimental vhost zero copy support). - Address Ian's comments: - Drop patch 01 from previous series entirely; - Patch (now) 01/14 adds a new call to dpdk_buf_size() inside dpdk_mp_create() to get the correct "mbuf_size" to be used; - Patch (now) 11/14 modifies dpdk_mp_create() to check if multi-segment mbufs is enabled, in which case it calculates the new "mbuf_size" to be used; - In free_dpdk_buf() and dpdk_buf_alloc(), don't lock and unlock conditionally. - Add "per-port-memory=true" to test "Multi-segment mbufs Tx" as the current DPDK set up in system-dpdk-testsuite can't handle higher MTU sizes using the shared mempool model (runs out of memory); - Add new examples for when multi-segment mbufs are enabled in topics/dpdk/memory.rst, and a reference to topics/dpdk/jumbo-frames.rst (now patch 11/14). v4: - Rebase on master b22fb00 ("ovn-nbctl: Clarify error messages in qos-add command."): - A new patch (now 01/15) has been introduced to differentiate between MTU and mbuf size when creating the mempool. This is because as part of the new support for both per port and shared mempools, mempools were being reused based on the mbuf size, and for multi-segment mbufs the mbuf size can end up being the same for all mbufs; - A couple of other patches (now 02/15 and 12/15) have been modified as part of the rebase, but only to adapt to the code changes to "Support both shared and per port mempools.", no functionality should have been changed. v3: - Address Eelco's comment: - Fix the ovs_assert() introduced in v2 in __packet_set_data(), which wasn't correctly asserting that the passed 'v' was smaller than the first mbuf's buf_len. v2: - Rebase on master e7cd8cf ("db-ctl-base: Don't die in cmd_destroy() on error."); - Address Eelco's comments: - In free_dpdk_buf(), use mbuf's struct address in dp_packet instead of casting; - Remove unneeded variable in dp_packet_set_size(), pointing to the first mbuf in the chain; - Assert in dp_packet_set_size() to enforce that "pkt_len == v" is always true for DPBUF_DPDK packets; - Assert in __packet_set_data() to enforce that data_off never goes beyond the first mbuf in the chain. v1: - v8 should have been sent as v1 really, as that's usually the approach followed in OvS. That clearly didn't happen, so restarting the series now. This also helps making it clear it is no longer an RFC series; - Rebase on master e461481 ("ofp-meter: Fix ofp_print_meter_flags() output."); - Address Eelco's comments: - Change dp_packet_size() so that for `DPBUF_DPDK` packets their `pkt_len` and `data_len` can't be set to values bigger than the available space. Also fix assigment to `data_len` which was incorrectly being set to just`pkt_len`; - Improve `nonpmd_mp_mutex` comment with a better explanation as to why the mutex is needed; - Fix dp_packet_clear() to not call rte_pktmbuf_reset() for non `DPBUF_DPDK` packets; - Dropped `if` clause in dp_packet_l4_size(), keep just the `else`; - Change dp_packet_clone_with_headroom() to use rte_pktmbuf_read() for copying `DPBUF_DPDK` packets' data. Also, change it to return appropriate and meaningful errors, instead of just "0" or "1"; - Change dpdk_prep_tx_buf() name's to dpdk_clone_dp_packet_to_mbuf(), and reuse dp_packet_mbuf_write() instead of manual copy; - Add note vswitchd/vswitch.xml to make it clear the enabling of dpdk-multi-seg-mbufs requires a restart; - Change dpdk_mp_create() to increase # mbufs used under the multi-segment mbufs approach; - Increase test coverage by adding "end-to-end" tests that verify that "dpdk-multi-seg-mbufs" is disabled by default and that a packet is successfully sent out; - Some helper funcs such as dp_packet_tail() and dp_packet_end() were moved back to be common between `DPBUF_DPDK` and non `DPBUF_DPDK` packets, to minimise changes; - Add some extra notes to "Performance notes" in jumbo-frames.rst doc, after further testing; - Structure changes: - Drop patch 07/13 which is now unneeded; - Two more patches added for extra test coverage. This is what accounts for the increase in size (+1 patch) in the series. v8 (non-RFC): - Rebase on master 88125d6 ("rhel: remove ovs-sim man page from temporary directory (also for RHEL)"); - Address Ciara's and Ilya's comments: - Drop the dp_packet_mbuf_tail() function and use only the already existing dp_packet_tail(); - Fix bug in dpdk_do_tx_copy() where the error return from dpdk_prep_tx_buf() was being wrongly checked; - Use dpdk_buf_alloc() and free_dpdk_buf() instead of rte_pktmbuf_alloc() and rte_pktmbuf_free(); - Fix some other code style and duplication issues pointed out. - Refactored dp_packet_shift(), dp_packet_resize__() and dp_packet_put*() functions to work within the bounds of existing mbufs only; - Fix dp_packet_clear() which wasn't correctly clearing / freeing other mbufs in the chain for chains with more than a single mbuf; - dp_packet layer functions (such as dp_packet_l3()) now check if the header is within the first mbuf, when using mbufs; - Move patch 08/13 to before patch 04/13, since dp_packet_set_size() was refactored to use free_dpdk_buf(); - Fix wrong rte_memcpy() when performing dp_packet_clone() which was leading to memory corruption; - Modified the added tests to account for some of the above changes; - Run performance tests, compiling results and adding them to the cover letter; - Add a multi-seg mbufs explanation to the jumbo-frames.rst doc, together with a "Performance notes" sub-section reflecting the findings mentioned above in the cover letter. v7: - Rebase on master 5e720da ("erspan: fix invalid erspan version."); - Address Ilya comments; - Fix non-DPDK build; - Serialise the access of non pmds to allocation and free of mbufs by using a newly introduced mutex. - Add a new set of tests that integrates with the recently added DPDK testsuite. These focus on allocating dp_packets, with a single or multiple mbufs, from an instantiated mempool and performing several operations on those, verifying if the data at the end matches what's expected; - Fix bugs found by the new tests: - dp_packet_shift() wasn't taking into account shift lefts; - dp_packet_resize__() was misusing and miscalculating the tailrooms and headrooms, ending up calculating the wrong number of segments that needed allocation; - An mbuf's end was being miscalculated both in dp_packet_tail, dp_packet_mbuf_tail() and dp_packet_end(); - dp_packet_set_size() was not updating the number of chained segments 'nb_segs'; - Add support for multi-seg mbufs in dp_packet_clear(). v6: - Rebase on master 7c0cb29 ("conntrack-tcp: Handle tcp session reuse."); - Further improve dp_packet_put_uninit() and dp_packet_shift() to support multi-seg mbufs; - Add support for multi-seg mbufs in dp_packet_l4_size() and improve other helper funcs, such as dp_packet_tail() and dp_ packet_tailroom(). - Add support for multi-seg mbufs in dp_packet_put(), dp_packet_ put_zeros(), as well as dp_packet_resize__() - allocating new mbufs and linking them together; Restructured patchset: - Squash patch 5 into patch 6, since they were both related to copying data while handling multi-seg mbufs; - Split patch 4 into two separate patches - one that introduces the changes in helper functions to deal with multi-seg mbufs and two others for the shift() and put_uninit() functionality; - Move patch 4 to before patch 3, so that ihelper functions come before functionality improvement that rely on those helpers. v5: - Rebased on master e5e22dc ("datapath-windows: Prevent ct-counters from getting redundantly incremented"); - Sugesh's comments have been addressed: - Changed dp_packet_set_data() and dp_packet_set_size() logic to make them independent of each other; - Dropped patch 3 now that dp_packet_set_data() and dp_packet_set_ size() are independent; - dp_packet_clone_with_headroom() now has split functions for handling DPDK sourced packets and non-DPDK packets; - Modified various functions in dp-packet.h to account for multi-seg mbufs - dp_packet_put_uninit(), dp_packet_tail(), dp_packet_tail() and dp_packet_at(); - Added support for shifting packet data in multi-seg mbufs, using dp_packet_shift(); - Fixed some minor inconsistencies. Note that some of the changes in v5 have been contributed by Mark Kavanagh as well. v4: - restructure patchset - account for 128B ARM cacheline when sizing mbufs Mark Kavanagh (2): netdev-dpdk: copy large packet to multi-seg. mbufs netdev-dpdk: support multi-segment jumbo frames Michael Qiu (1): dp-packet: copy data from multi-seg. DPDK mbuf Tiago Lam (8): netdev-dpdk: Serialise non-pmds mbufs' alloc/free. dp-packet: Fix data_len handling multi-seg mbufs. dp-packet: Handle multi-seg mbufs in helper funcs. dp-packet: Handle multi-seg mubfs in shift() func. dp-packet: Add support for data "linearization". dpdk-tests: Add unit-tests for multi-seg mbufs. dpdk-tests: Accept other configs in OVS_DPDK_START dpdk-tests: End-to-end tests for multi-seg mbufs. Documentation/topics/dpdk/jumbo-frames.rst | 73 +++ Documentation/topics/dpdk/memory.rst | 36 ++ NEWS | 1 + lib/conntrack.c | 5 + lib/crc32c.c | 17 +- lib/crc32c.h | 2 + lib/dp-packet.c | 189 +++++++- lib/dp-packet.h | 485 +++++++++++++++++-- lib/dpdk.c | 8 + lib/dpif-netdev.c | 18 +- lib/dpif-netlink.c | 3 + lib/dpif.c | 6 + lib/flow.c | 113 ++++- lib/flow.h | 4 +- lib/mcast-snooping.c | 2 + lib/netdev-bsd.c | 3 + lib/netdev-dpdk.c | 190 +++++++- lib/netdev-dpdk.h | 1 + lib/netdev-dummy.c | 6 + lib/netdev-linux.c | 6 + lib/netdev-native-tnl.c | 26 +- lib/odp-execute.c | 24 +- lib/packets.c | 96 +++- lib/packets.h | 7 + ofproto/ofproto-dpif-upcall.c | 21 +- ofproto/ofproto-dpif-xlate.c | 27 +- tests/automake.mk | 10 +- tests/dpdk-packet-mbufs.at | 7 + tests/system-dpdk-macros.at | 6 +- tests/system-dpdk-testsuite.at | 1 + tests/system-dpdk.at | 65 +++ tests/test-dpdk-mbufs.c | 722 +++++++++++++++++++++++++++++ tests/test-rstp.c | 9 +- tests/test-stp.c | 9 +- vswitchd/vswitch.xml | 22 + 35 files changed, 2068 insertions(+), 152 deletions(-) create mode 100644 tests/dpdk-packet-mbufs.at create mode 100644 tests/test-dpdk-mbufs.c