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https://github.com/hanzoai/visor.git
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Andrei Vagin
43bd258fcf
It is an idea of running codespell as part of our presubmit checks. Before enabling it for new changes, let's fix what it has found. Signed-off-by: Andrei Vagin <[email protected]>
44 lines
1.6 KiB
Go
44 lines
1.6 KiB
Go
// Copyright 2018 The gVisor Authors.
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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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//go:build arm64
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// +build arm64
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package time
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// getCNTFRQ get ARM counter-timer frequency
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func getCNTFRQ() TSCValue
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// getDefaultArchOverheadCycles get default OverheadCycles based on
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// ARM counter-timer frequency. Usually ARM counter-timer frequency
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// is range from 1-50Mhz which is much less than that on x86, so we
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// calibrate defaultOverheadCycles for ARM.
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func getDefaultArchOverheadCycles() TSCValue {
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// estimated the clock frequency on x86 is 1Ghz.
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// 1Ghz divided by counter-timer frequency of ARM to get
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// frqRatio. defaultOverheadCycles of ARM equals to that on
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// x86 divided by frqRatio
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cntfrq := getCNTFRQ()
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frqRatio := 1000000000 / float64(cntfrq)
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overheadCycles := (1 * 1000) / frqRatio
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return TSCValue(overheadCycles)
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}
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// defaultOverheadTSC is the default estimated syscall overhead in TSC cycles.
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// It is further refined as syscalls are made.
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var defaultOverheadCycles = getDefaultArchOverheadCycles()
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// maxOverheadCycles is the maximum allowed syscall overhead in TSC cycles.
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var maxOverheadCycles = 100 * defaultOverheadCycles
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