mirror of
https://github.com/openvswitch/ovs
synced 2025-08-22 09:58:01 +00:00
d90b4f2928
Some older wireless drivers - ones relying on the old and long deprecated wireless extension ioctl system - can generate quite a bit of IFLA_WIRELESS events depending on their configuration and runtime conditions. These are delivered as RTNLGRP_LINK via RTM_NEWLINK messages. These tend to be relatively easily identifiable because they report the change mask being 0. This isn't guaranteed but in practice it shouldn't be a problem. None of the wireless events that I ever observed actually carry any unique information about netdev states that ovs-vswitchd is interested in. Hence ignoring these shouldn't cause any problems. These events can be responsible for a significant CPU churn as ovs-vswitchd attempts to do plenty of work for each and every netlink message regardless of what that message carries. On low-end devices such as consumer-grade routers these can lead to a lot of CPU cycles being wasted, adding up to heat output and reducing performance. It could be argued that wireless drivers in question should be fixed, but that isn't exactly a trivial thing to do. Patching ovs seems far more viable while still making sense. Signed-off-by: Michal Kazior <michal@plume.com> Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
72 lines
1.6 KiB
C
72 lines
1.6 KiB
C
/*
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* Copyright (c) 2015 Red Hat, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <config.h>
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#include "if-notifier.h"
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#include "rtnetlink.h"
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#include "util.h"
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struct if_notifier {
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struct nln_notifier *notifier;
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if_notify_func *cb;
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void *aux;
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};
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static void
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if_notifier_cb(const struct rtnetlink_change *change, void *aux)
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{
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struct if_notifier *notifier;
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if (change && change->irrelevant) {
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return;
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}
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notifier = aux;
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notifier->cb(notifier->aux);
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}
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struct if_notifier *
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if_notifier_create(if_notify_func *cb, void *aux)
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{
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struct if_notifier *notifier;
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notifier = xmalloc(sizeof *notifier);
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notifier->cb = cb;
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notifier->aux = aux;
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notifier->notifier = rtnetlink_notifier_create(if_notifier_cb, notifier);
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return notifier;
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}
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void
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if_notifier_destroy(struct if_notifier *notifier)
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{
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if (notifier) {
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rtnetlink_notifier_destroy(notifier->notifier);
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free(notifier);
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}
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}
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void
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if_notifier_run(void)
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{
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rtnetlink_run();
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}
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void
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if_notifier_wait(void)
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{
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rtnetlink_wait();
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}
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