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authorAlexey Perevalov <a.perevalov@samsung.com>2018-03-22 21:17:25 +0300
committerDr. David Alan Gilbert <dgilbert@redhat.com>2018-04-25 18:02:16 +0100
commit9ed01779e8984b71cf62e4732de8d05ff091df36 (patch)
tree3086d632f22e3876552e5c5e2ddd2ee1e9c91297 /docs
parent575b0b332ea25986fd348c45a91e642bca912137 (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> Message-Id: <1521742647-25550-5-git-send-email-a.perevalov@samsung.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Diffstat (limited to 'docs')
-rw-r--r--docs/devel/migration.rst14
1 files changed, 14 insertions, 0 deletions
diff --git a/docs/devel/migration.rst b/docs/devel/migration.rst
index e32b087f6e..9342a8af06 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