mirror of
https://github.com/kubernetes-sigs/node-feature-discovery.git
synced 2024-12-14 11:57:51 +00:00
53 lines
1.5 KiB
Go
53 lines
1.5 KiB
Go
/*
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Copyright 2018 The Kubernetes Authors.
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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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http://www.apache.org/licenses/LICENSE-2.0
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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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package memory
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import (
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"fmt"
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"io/ioutil"
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"strings"
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"github.com/kubernetes-incubator/node-feature-discovery/source"
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)
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// Source implements FeatureSource.
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type Source struct{}
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// Name returns an identifier string for this feature source.
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func (s Source) Name() string { return "memory" }
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// Discover returns feature names for memory: numa if more than one memory node is present.
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func (s Source) Discover() (source.Features, error) {
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features := source.Features{}
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// Find out how many nodes are online
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// Multiple nodes is a sign of NUMA
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bytes, err := ioutil.ReadFile("/sys/devices/system/node/online")
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if err != nil {
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return nil, fmt.Errorf("can't read /sys/devices/system/node/online: %s", err.Error())
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}
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// File content is expected to be:
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// "0\n" in one-node case
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// "0-K\n" in N-node case where K=N-1
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// presence of newline requires TrimSpace
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if strings.TrimSpace(string(bytes)) != "0" {
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// more than one node means NUMA
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features["numa"] = true
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}
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return features, nil
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}
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