* Alexey Perevalov ([email protected]) wrote: > Reviewed-by: Dr. David Alan Gilbert <[email protected]> > Signed-off-by: Alexey Perevalov <[email protected]>
Although it does have my R-b it might be worth adding some clarification that it's a measure of when *all* cpus are blocked and so isn't a total measure of impact of postcopy (when blocking some of them). Dave > --- > docs/devel/migration.txt | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/docs/devel/migration.txt b/docs/devel/migration.txt > index 1b940a8..4b625ca 100644 > --- a/docs/devel/migration.txt > +++ b/docs/devel/migration.txt > @@ -402,6 +402,16 @@ 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. > +This value is 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. > + > 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). > -- > 1.9.1 > -- Dr. David Alan Gilbert / [email protected] / Manchester, UK
