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{ "id": 2228721, "url": "http://patchwork.ozlabs.org/api/covers/2228721/?format=api", "web_url": "http://patchwork.ozlabs.org/project/openvswitch/cover/20260427091153.3210301-1-amorenoz@redhat.com/", "project": { "id": 47, "url": "http://patchwork.ozlabs.org/api/projects/47/?format=api", "name": "Open vSwitch", "link_name": "openvswitch", "list_id": "ovs-dev.openvswitch.org", "list_email": "ovs-dev@openvswitch.org", "web_url": "http://openvswitch.org/", "scm_url": "git@github.com:openvswitch/ovs.git", "webscm_url": "https://github.com/openvswitch/ovs", "list_archive_url": "", "list_archive_url_format": "", "commit_url_format": "" }, "msgid": "<20260427091153.3210301-1-amorenoz@redhat.com>", "list_archive_url": null, "date": "2026-04-27T09:11:46", "name": "[ovs-dev,net-next,v3,0/2] Decouple flow operations from RTNL", "submitter": { "id": 77477, "url": "http://patchwork.ozlabs.org/api/people/77477/?format=api", "name": "Adrian Moreno", "email": "amorenoz@redhat.com" }, "mbox": "http://patchwork.ozlabs.org/project/openvswitch/cover/20260427091153.3210301-1-amorenoz@redhat.com/mbox/", "series": [ { "id": 501610, "url": "http://patchwork.ozlabs.org/api/series/501610/?format=api", "web_url": "http://patchwork.ozlabs.org/project/openvswitch/list/?series=501610", "date": "2026-04-27T09:11:46", "name": "Decouple flow operations from RTNL", "version": 3, "mbox": "http://patchwork.ozlabs.org/series/501610/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/covers/2228721/comments/", "headers": { "Return-Path": "<ovs-dev-bounces@openvswitch.org>", "X-Original-To": [ "incoming@patchwork.ozlabs.org", "dev@openvswitch.org" ], "Delivered-To": [ "patchwork-incoming@legolas.ozlabs.org", "ovs-dev@lists.linuxfoundation.org" ], "Authentication-Results": [ "legolas.ozlabs.org;\n\tdkim=fail reason=\"signature verification failed\" (1024-bit key;\n unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256\n header.s=mimecast20190719 header.b=UfKaWJk0;\n\tdkim-atps=neutral", "legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=openvswitch.org\n (client-ip=2605:bc80:3010::133; 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receiver=<UNKNOWN> ", "DKIM-Filter": [ "OpenDKIM Filter v2.11.0 smtp2.osuosl.org 4864240227", "OpenDKIM Filter v2.11.0 smtp1.osuosl.org 29ACD854F2" ], "Received-SPF": "Pass (mailfrom) identity=mailfrom; client-ip=170.10.133.124;\n helo=us-smtp-delivery-124.mimecast.com; envelope-from=amorenoz@redhat.com;\n receiver=<UNKNOWN>", "DMARC-Filter": "OpenDMARC Filter v1.4.2 smtp1.osuosl.org 29ACD854F2", "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com;\n s=mimecast20190719; t=1777281126;\n h=from:from:reply-to:subject:subject:date:date:message-id:message-id:\n to:to:cc:cc:mime-version:mime-version:content-type:content-type:\n content-transfer-encoding:content-transfer-encoding;\n bh=nxu8EEl/NSWtPFSsHpu2gcxuc2ncIwFUJimar90n8NA=;\n b=UfKaWJk09VwzL6dYUVZIOXzcT9x/Cg3HhQcTiVadcAtmR9t9WfA3cjE0CszcVRTD8TnctT\n RrXA5vr3pts2Pp+YB9mAGFLiTLhTSvfRIoqBzDveq5rRzem6Fbliz8QtxcrNEdlyyfl1zh\n +hq8JGwMh7tBPJimdQIXSL02C//PmOg=", "X-MC-Unique": "8kmpqUAEPUmG_aAUQJJJGA-1", "X-Mimecast-MFC-AGG-ID": "8kmpqUAEPUmG_aAUQJJJGA_1777281123", "To": "netdev@vger.kernel.org", "Date": "Mon, 27 Apr 2026 11:11:46 +0200", "Message-ID": "<20260427091153.3210301-1-amorenoz@redhat.com>", "MIME-Version": "1.0", "X-Scanned-By": "MIMEDefang 3.4.1 on 10.30.177.111", "X-Mimecast-MFC-PROC-ID": "ryPRpMoMx6HnKvy49qXBt7JgBzTCPgOA6T106nz91-c_1777281123", "X-Mimecast-Originator": "redhat.com", "Subject": "[ovs-dev] [PATCH net-next v3 0/2] Decouple flow operations from RTNL", "X-BeenThere": "ovs-dev@openvswitch.org", "X-Mailman-Version": "2.1.30", "Precedence": "list", "List-Id": "<ovs-dev.openvswitch.org>", "List-Unsubscribe": "<https://mail.openvswitch.org/mailman/options/ovs-dev>,\n <mailto:ovs-dev-request@openvswitch.org?subject=unsubscribe>", "List-Archive": "<http://mail.openvswitch.org/pipermail/ovs-dev/>", "List-Post": "<mailto:ovs-dev@openvswitch.org>", "List-Help": "<mailto:ovs-dev-request@openvswitch.org?subject=help>", "List-Subscribe": "<https://mail.openvswitch.org/mailman/listinfo/ovs-dev>,\n <mailto:ovs-dev-request@openvswitch.org?subject=subscribe>", "From": "Adrian Moreno via dev <ovs-dev@openvswitch.org>", "Reply-To": "Adrian Moreno <amorenoz@redhat.com>", "Cc": "\"open list:OPENVSWITCH\" <dev@openvswitch.org>,\n open list <linux-kernel@vger.kernel.org>, Simon Horman <horms@kernel.org>,\n pabeni@redhat.com", "Content-Type": "text/plain; charset=\"us-ascii\"", "Content-Transfer-Encoding": "7bit", "Errors-To": "ovs-dev-bounces@openvswitch.org", "Sender": "\"dev\" <ovs-dev-bounces@openvswitch.org>" }, "content": "When RTNL is contended, network-related control-plane operations can be\ndelayed.\n\nIn such scenario, if OVS control-plane operations (such as vport\ncreation) take a bit longer, it's acceptable. However, flow installation\noperations happen as part of upcall processing, executed in the context\nof of handler threads. If they get delayed, it affects the data-plane\nand can even result in packet drops.\n\nBecause flow operations also use ovs_mutex for concurrency protection and\ngiven RTNL can nest under ovs_mutex, contention can be easily transferred\nfrom RTNL to ovs_mutex, causing delay in flow operations.\n\nIn order to protect flow operations from RTNL delays, this series\ndecouples them from ovs_mutex. First, the flow_table is converted into an\nrcu-protected pointer. Then two locking mechanisms are introduced: a\nper-table mutex and a refcount.\n\nThe mutex protects the flow_table against concurrent modifications,\nwhile the refcount is used to extend the lifetime of the flow_table\nbeyond the rcu read-protected region used to dereference it.\n\nv3:\n- Split in 2 patches (Paolo)\n- Improve locking in get_dp_stats (Paolo and Sashiko)\n- Use __always_unused in lockdep stubs (Paolo)\n- Use READ_ONCE/WRITE_ONCE for table->count (Aaron)\n- Take a reference in ovs_dp_masks_rebalance (Aaron) \n\nv2: Fix argument in ovs_flow_tbl_put (sparse)\n Remove rcu checks in ovs_dp_masks_rebalance\n\nAdrian Moreno (2):\n net: openvswitch: make flow_table an rcu pointer\n net: openvswitch: decouple flow_table from ovs_mutex\n\n net/openvswitch/datapath.c | 293 ++++++++++++++++++++++++-----------\n net/openvswitch/datapath.h | 2 +-\n net/openvswitch/flow.c | 13 +-\n net/openvswitch/flow.h | 9 +-\n net/openvswitch/flow_table.c | 194 ++++++++++++++---------\n net/openvswitch/flow_table.h | 56 ++++++-\n 6 files changed, 396 insertions(+), 171 deletions(-)" }