From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51370) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dv2ee-0007dh-09 for qemu-devel@nongnu.org; Thu, 21 Sep 2017 10:40:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dv2eb-00083M-0J for qemu-devel@nongnu.org; Thu, 21 Sep 2017 10:40:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33078) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dv2ea-00082Z-NK for qemu-devel@nongnu.org; Thu, 21 Sep 2017 10:40:36 -0400 Date: Thu, 21 Sep 2017 15:40:27 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20170921144026.GJ2717@work-vm> References: <1505839684-10046-1-git-send-email-a.perevalov@samsung.com> <1505839684-10046-9-git-send-email-a.perevalov@samsung.com> <20170921123326.GD2717@work-vm> <0c0baef1-fbad-e6d2-8d8b-07f54d084ee9@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0c0baef1-fbad-e6d2-8d8b-07f54d084ee9@samsung.com> Subject: Re: [Qemu-devel] [PATCH v10 08/10] migration: postcopy_blocktime documentation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Perevalov Cc: qemu-devel@nongnu.org, i.maximets@samsung.com, peterx@redhat.com, eblake@redhat.com, quintela@redhat.com, heetae82.ahn@samsung.com * Alexey Perevalov (a.perevalov@samsung.com) wrote: > On 09/21/2017 03:33 PM, Dr. David Alan Gilbert wrote: > > * Alexey Perevalov (a.perevalov@samsung.com) wrote: > > > Reviewed-by: Dr. David Alan Gilbert > > > Signed-off-by: Alexey Perevalov > > 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). > yes, maybe additional clarification is necessary. > now we have both values: > {"return": {"postcopy-blocktime": 5691, "status": "completed", > "postcopy-vcpu-blocktime": [7671, 6388]}} > where postcopy-blocktime is for *all* and postcopy-vcpu-blocktime is per > vCPU, > it's really worth to describe it, like: > > Blocktime is a postcopy live migration metric, intended to show > how long the vCPU was in state of interruptible 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. Yep that seems OK. Dave > -- > Best regards, > Alexey Perevalov > > > > > 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 / dgilbert@redhat.com / Manchester, UK > > > > > > > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK