Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com> Signed-off-by: Alexey Perevalov <a.pereva...@samsung.com> --- docs/devel/migration.txt | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/docs/devel/migration.txt b/docs/devel/migration.txt index 4030703..cebfe7a 100644 --- a/docs/devel/migration.txt +++ b/docs/devel/migration.txt @@ -402,6 +402,19 @@ 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 the destination is waiting for). -- 2.7.4
