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| author | Alexey Perevalov <a.perevalov@samsung.com> | 2017-10-30 16:16:28 +0300 |
|---|---|---|
| committer | Juan Quintela <quintela@redhat.com> | 2018-01-15 12:48:02 +0100 |
| commit | 2f7dae9dd3b5bb436f6089816cf24f4d0867d32e (patch) | |
| tree | 3e585695990fba589d1a007a9b243c0dac8d5ddd /docs | |
| parent | 3be98be4e9f59055afb5f2b27f9296c7093b4e75 (diff) | |
migration: postcopy_blocktime documentation
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Alexey Perevalov <a.perevalov@samsung.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/devel/migration.rst | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/docs/devel/migration.rst b/docs/devel/migration.rst index bf97080dac..015a9ebdf7 100644 --- a/docs/devel/migration.rst +++ b/docs/devel/migration.rst @@ -401,6 +401,20 @@ will now cause the transition from precopy to postcopy. It can be issued immediately after migration is started or any time later on. Issuing it after the end of a migration is harmless. +Blocktime is a postcopy live migration metric, intended to show how +long the vCPU was in state of interruptable sleep due to pagefault. +That metric is calculated both for all vCPUs as overlapped value, and +separately for each vCPU. These values are calculated on destination +side. To enable postcopy blocktime calculation, enter following +command on destination monitor: + +``migrate_set_capability postcopy-blocktime on`` + +Postcopy blocktime can be retrieved by query-migrate qmp command. +postcopy-blocktime value of qmp command will show overlapped blocking +time for all vCPU, postcopy-vcpu-blocktime will show list of blocking +time per vCPU. + .. note:: During the postcopy phase, the bandwidth limits set using ``migrate_set_speed`` is ignored (to avoid delaying requested pages that |