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| author | Paolo Bonzini <pbonzini@redhat.com> | 2016-10-13 13:10:57 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-10-27 11:35:47 +0200 |
| commit | 58e3948a87e39289aeda5753e9712092c8ca0745 (patch) | |
| tree | a9b200b62b48ac44c5326c4c9fa95f9bf2ed96a0 /Documentation/virtual | |
| parent | 36343f6ea721e003ed11b48a6a05d77a255b3a62 (diff) | |
| download | linux-58e3948a87e39289aeda5753e9712092c8ca0745.tar.bz2 | |
KVM: document lock orders
This is long overdue, and not really hard.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1476357057-17899-1-git-send-email-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'Documentation/virtual')
| -rw-r--r-- | Documentation/virtual/kvm/locking.txt | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/Documentation/virtual/kvm/locking.txt b/Documentation/virtual/kvm/locking.txt index f2491a8c68b4..e5dd9f4d6100 100644 --- a/Documentation/virtual/kvm/locking.txt +++ b/Documentation/virtual/kvm/locking.txt @@ -4,7 +4,17 @@ KVM Lock Overview 1. Acquisition Orders --------------------- -(to be written) +The acquisition orders for mutexes are as follows: + +- kvm->lock is taken outside vcpu->mutex + +- kvm->lock is taken outside kvm->slots_lock and kvm->irq_lock + +- kvm->slots_lock is taken outside kvm->irq_lock, though acquiring + them together is quite rare. + +For spinlocks, kvm_lock is taken outside kvm->mmu_lock. Everything +else is a leaf: no other lock is taken inside the critical sections. 2: Exception ------------ |