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timecounter: Initialize tc_lock earlier
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Authored by markj on Nov 16 2021, 8:46 PM.

Details

Summary

Hyper-V wants to register its MSR-based timecounter during
SI_SUB_HYPERVISOR, before SI_SUB_LOCK, since an emulated 8254 may not be
available. So we cannot use MTX_SYSINIT to initialize the timecounter
lock.

This change reverts commit 9ef7df022a46 ("hyperv: Register
hyperv_timecounter later during boot") and adds some comments explaining
why things are the way they are.

PR: 259878

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Repository
rG FreeBSD src repository
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Unit
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