From 9ed01779e8984b71cf62e4732de8d05ff091df36 Mon Sep 17 00:00:00 2001 From: Alexey Perevalov Date: Thu, 22 Mar 2018 21:17:25 +0300 Subject: [PATCH] migration: postcopy_blocktime documentation Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Alexey Perevalov Reviewed-by: Juan Quintela Signed-off-by: Juan Quintela Message-Id: <1521742647-25550-5-git-send-email-a.perevalov@samsung.com> Signed-off-by: Dr. David Alan Gilbert --- docs/devel/migration.rst | 14 ++++++++++++++ 1 file changed, 14 insertions(+) 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 -- 2.11.4.GIT