From: Roman Kagan <rkagan@virtuozzo.com>
To: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: "ehabkost@redhat.com" <ehabkost@redhat.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"Li, Liang Z" <liang.z.li@intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"mst@redhat.com" <mst@redhat.com>,
"amit.shah@redhat.com" <amit.shah@redhat.com>,
Paolo Bonzini <pbonzini@redhat.com>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"virtualization@lists.linux-foundation.org"
<virtualization@lists.linux-foundation.org>,
"rth@twiddle.net" <rth@twiddle.net>
Subject: Re: [Qemu-devel] [RFC qemu 0/4] A PV solution for live migration optimization
Date: Wed, 9 Mar 2016 16:22:11 +0300 [thread overview]
Message-ID: <20160309132210.GA5869__44243.7048689046$1457529769$gmane$org@rkaganb.sw.ru> (raw)
In-Reply-To: <20160304185120.GB2588@work-vm>
On Fri, Mar 04, 2016 at 06:51:21PM +0000, Dr. David Alan Gilbert wrote:
> * Paolo Bonzini (pbonzini@redhat.com) wrote:
> >
> >
> > On 04/03/2016 15:26, Li, Liang Z wrote:
> > >> >
> > >> > The memory usage will keep increasing due to ever growing caches, etc, so
> > >> > you'll be left with very little free memory fairly soon.
> > >> >
> > > I don't think so.
> > >
> >
> > Roman is right. For example, here I am looking at a 64 GB (physical)
> > machine which was booted about 30 minutes ago, and which is running
> > disk-heavy workloads (installing VMs).
> >
> > Since I have started writing this email (2 minutes?), the amount of free
> > memory has already gone down from 37 GB to 33 GB. I expect that by the
> > time I have finished running the workload, in two hours, it will not
> > have any free memory.
>
> But what about a VM sitting idle, or that just has more RAM assigned to it
> than is currently using.
> I've got a host here that's been up for 46 days and has been doing some
> heavy VM debugging a few days ago, but today:
>
> # free -m
> total used free shared buff/cache available
> Mem: 96536 1146 44834 184 50555 94735
>
> I very rarely use all it's RAM, so it's got a big chunk of free RAM, and yes
> it's got a big chunk of cache as well.
One of the promises of virtualization is better resource utilization.
People tend to avoid purchasing VMs so much oversized that they never
touch a significant amount of their RAM. (Well, at least this is how
things stand in hosting market; I guess enterprize market is similar in
this regard).
That said, I'm not at all opposed to optimizing the migration of free
memory; what I'm trying to say is that creating brand new infrastructure
specifically for that case doesn't look justified when the existing one
can cover it in addition to much more common scenarios.
Roman.
next prev parent reply other threads:[~2016-03-09 13:22 UTC|newest]
Thread overview: 292+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-03 10:44 [RFC qemu 0/4] A PV solution for live migration optimization Liang Li
2016-03-03 10:44 ` [Qemu-devel] " Liang Li
2016-03-03 10:44 ` Liang Li
2016-03-03 10:44 ` [RFC qemu 1/4] pc: Add code to get the lowmem form PCMachineState Liang Li
2016-03-03 10:44 ` [Qemu-devel] " Liang Li
2016-03-03 10:44 ` Liang Li
2016-03-03 10:44 ` Liang Li
2016-03-03 10:44 ` [RFC qemu 2/4] virtio-balloon: Add a new feature to balloon device Liang Li
2016-03-03 10:44 ` Liang Li
2016-03-03 10:44 ` [Qemu-devel] " Liang Li
2016-03-03 10:44 ` Liang Li
2016-03-03 12:23 ` Cornelia Huck
2016-03-03 12:23 ` Cornelia Huck
2016-03-03 12:23 ` [Qemu-devel] " Cornelia Huck
2016-03-03 12:23 ` Cornelia Huck
2016-03-04 2:38 ` Li, Liang Z
2016-03-04 2:38 ` [Qemu-devel] " Li, Liang Z
2016-03-04 2:38 ` Li, Liang Z
2016-03-04 2:38 ` Li, Liang Z
2016-03-03 12:56 ` Michael S. Tsirkin
2016-03-03 12:56 ` Michael S. Tsirkin
2016-03-03 12:56 ` [Qemu-devel] " Michael S. Tsirkin
2016-03-03 12:56 ` Michael S. Tsirkin
2016-03-04 2:29 ` Li, Liang Z
2016-03-04 2:29 ` [Qemu-devel] " Li, Liang Z
2016-03-04 2:29 ` Li, Liang Z
2016-03-04 2:29 ` Li, Liang Z
2016-03-03 10:44 ` [RFC qemu 3/4] migration: not set migration bitmap in setup stage Liang Li
2016-03-03 10:44 ` [Qemu-devel] " Liang Li
2016-03-03 10:44 ` Liang Li
2016-03-03 10:44 ` Liang Li
2016-03-03 10:44 ` [RFC qemu 4/4] migration: filter out guest's free pages in ram bulk stage Liang Li
2016-03-03 10:44 ` [Qemu-devel] " Liang Li
2016-03-03 10:44 ` Liang Li
2016-03-03 12:16 ` Cornelia Huck
2016-03-03 12:16 ` [Qemu-devel] " Cornelia Huck
2016-03-03 12:16 ` Cornelia Huck
2016-03-03 12:16 ` Cornelia Huck
2016-03-04 2:32 ` Li, Liang Z
2016-03-04 2:32 ` Li, Liang Z
2016-03-04 2:32 ` [Qemu-devel] " Li, Liang Z
2016-03-04 2:32 ` Li, Liang Z
2016-03-04 2:32 ` Li, Liang Z
2016-03-03 12:45 ` [Qemu-devel] " Daniel P. Berrange
2016-03-03 12:45 ` Daniel P. Berrange
2016-03-03 12:45 ` Daniel P. Berrange
2016-03-03 12:45 ` Daniel P. Berrange
2016-03-04 2:43 ` Li, Liang Z
2016-03-04 2:43 ` Li, Liang Z
2016-03-04 2:43 ` Li, Liang Z
2016-03-04 2:43 ` Li, Liang Z
2016-03-03 10:44 ` Liang Li
2016-03-03 13:58 ` [Qemu-devel] [RFC qemu 0/4] A PV solution for live migration optimization Roman Kagan
2016-03-03 13:58 ` Roman Kagan
2016-03-03 13:58 ` Roman Kagan
2016-03-03 13:58 ` Roman Kagan
2016-03-04 1:35 ` Li, Liang Z
2016-03-04 1:35 ` Li, Liang Z
2016-03-04 1:35 ` Li, Liang Z
2016-03-04 1:35 ` Li, Liang Z
2016-03-03 17:46 ` Dr. David Alan Gilbert
2016-03-03 17:46 ` [Qemu-devel] " Dr. David Alan Gilbert
2016-03-03 17:46 ` Dr. David Alan Gilbert
2016-03-04 1:52 ` Li, Liang Z
2016-03-04 1:52 ` [Qemu-devel] " Li, Liang Z
2016-03-04 1:52 ` Li, Liang Z
2016-03-04 1:52 ` Li, Liang Z
2016-03-04 8:14 ` [Qemu-devel] " Roman Kagan
2016-03-04 8:14 ` Roman Kagan
2016-03-04 8:14 ` Roman Kagan
2016-03-04 8:14 ` Roman Kagan
2016-03-04 9:08 ` Li, Liang Z
2016-03-04 9:08 ` Li, Liang Z
2016-03-04 9:08 ` Li, Liang Z
2016-03-04 10:23 ` Roman Kagan
2016-03-04 10:23 ` Roman Kagan
2016-03-04 10:23 ` Roman Kagan
2016-03-04 14:26 ` Li, Liang Z
2016-03-04 14:26 ` Li, Liang Z
2016-03-04 14:26 ` Li, Liang Z
2016-03-04 14:26 ` Li, Liang Z
2016-03-04 14:45 ` Michael S. Tsirkin
2016-03-04 14:45 ` Michael S. Tsirkin
2016-03-04 14:45 ` Michael S. Tsirkin
2016-03-04 14:45 ` Michael S. Tsirkin
2016-03-04 15:49 ` Li, Liang Z
2016-03-04 15:49 ` Li, Liang Z
2016-03-04 15:49 ` Li, Liang Z
2016-03-04 15:49 ` Li, Liang Z
2016-03-05 19:55 ` Michael S. Tsirkin
2016-03-05 19:55 ` Michael S. Tsirkin
2016-03-05 19:55 ` Michael S. Tsirkin
2016-03-05 19:55 ` Michael S. Tsirkin
2016-03-05 19:55 ` Michael S. Tsirkin
2016-03-07 6:49 ` Li, Liang Z
2016-03-07 6:49 ` Li, Liang Z
2016-03-07 6:49 ` Li, Liang Z
2016-03-07 6:49 ` Li, Liang Z
2016-03-07 11:40 ` Michael S. Tsirkin
2016-03-07 11:40 ` Michael S. Tsirkin
2016-03-07 11:40 ` Michael S. Tsirkin
2016-03-07 11:40 ` Michael S. Tsirkin
2016-03-07 15:06 ` Li, Liang Z
2016-03-07 15:06 ` Li, Liang Z
2016-03-07 15:06 ` Li, Liang Z
2016-03-07 15:06 ` Li, Liang Z
2016-03-09 14:28 ` Roman Kagan
2016-03-09 14:28 ` Roman Kagan
2016-03-09 14:28 ` Roman Kagan
2016-03-09 14:28 ` Roman Kagan
2016-03-09 14:28 ` Roman Kagan
2016-03-09 15:27 ` Li, Liang Z
2016-03-09 15:27 ` Li, Liang Z
2016-03-09 15:27 ` Li, Liang Z
2016-03-09 15:27 ` Li, Liang Z
2016-03-09 15:30 ` Michael S. Tsirkin
2016-03-09 15:30 ` Michael S. Tsirkin
2016-03-09 15:30 ` Michael S. Tsirkin
2016-03-10 1:41 ` Li, Liang Z
2016-03-10 1:41 ` Li, Liang Z
2016-03-10 1:41 ` Li, Liang Z
2016-03-10 1:41 ` Li, Liang Z
2016-03-10 1:41 ` Li, Liang Z
2016-03-10 12:29 ` Michael S. Tsirkin
2016-03-10 12:29 ` Michael S. Tsirkin
2016-03-10 12:29 ` Michael S. Tsirkin
2016-03-10 12:29 ` Michael S. Tsirkin
2016-03-09 15:30 ` Michael S. Tsirkin
2016-03-09 15:41 ` Michael S. Tsirkin
2016-03-09 15:41 ` Michael S. Tsirkin
2016-03-09 15:41 ` Michael S. Tsirkin
2016-03-09 17:04 ` Roman Kagan
2016-03-09 17:04 ` Roman Kagan
2016-03-09 17:04 ` Roman Kagan
2016-03-09 17:04 ` Roman Kagan
2016-03-09 17:04 ` Roman Kagan
2016-03-09 17:39 ` Michael S. Tsirkin
2016-03-09 17:39 ` Michael S. Tsirkin
2016-03-09 17:39 ` Michael S. Tsirkin
2016-03-10 10:21 ` Roman Kagan
2016-03-10 10:21 ` Roman Kagan
2016-03-10 10:21 ` Roman Kagan
2016-03-10 10:21 ` Roman Kagan
2016-03-09 19:38 ` Rik van Riel
2016-03-09 19:38 ` Rik van Riel
2016-03-09 19:38 ` Rik van Riel
2016-03-09 19:38 ` Rik van Riel
2016-03-10 9:30 ` Roman Kagan
2016-03-10 9:30 ` Roman Kagan
2016-03-10 9:30 ` Roman Kagan
2016-03-10 9:30 ` Roman Kagan
2016-03-09 15:41 ` Michael S. Tsirkin
2016-03-07 6:49 ` Li, Liang Z
2016-03-04 16:24 ` Paolo Bonzini
2016-03-04 16:24 ` Paolo Bonzini
2016-03-04 16:24 ` Paolo Bonzini
2016-03-04 16:24 ` Paolo Bonzini
2016-03-04 16:24 ` Paolo Bonzini
2016-03-04 18:51 ` Dr. David Alan Gilbert
2016-03-04 18:51 ` Dr. David Alan Gilbert
2016-03-04 18:51 ` Dr. David Alan Gilbert
2016-03-04 18:51 ` Dr. David Alan Gilbert
2016-03-07 5:34 ` Li, Liang Z
2016-03-07 5:34 ` Li, Liang Z
2016-03-07 5:34 ` Li, Liang Z
2016-03-07 5:34 ` Li, Liang Z
2016-03-07 5:34 ` Li, Liang Z
2016-03-09 13:22 ` Roman Kagan
2016-03-09 13:22 ` Roman Kagan
2016-03-09 13:22 ` Roman Kagan
2016-03-09 14:19 ` Li, Liang Z
2016-03-09 14:19 ` Li, Liang Z
2016-03-09 14:19 ` Li, Liang Z
2016-03-09 14:19 ` Li, Liang Z
2016-03-09 14:19 ` Li, Liang Z
2016-03-09 13:22 ` Roman Kagan [this message]
2016-03-09 6:18 ` Li, Liang Z
2016-03-09 6:18 ` Li, Liang Z
2016-03-09 6:18 ` Li, Liang Z
2016-03-09 6:18 ` Li, Liang Z
2016-03-09 6:18 ` Li, Liang Z
2016-03-04 10:23 ` Roman Kagan
2016-03-04 9:08 ` Li, Liang Z
2016-03-04 7:55 ` Roman Kagan
2016-03-04 7:55 ` Roman Kagan
2016-03-04 7:55 ` Roman Kagan
2016-03-04 7:55 ` Roman Kagan
2016-03-04 8:23 ` Li, Liang Z
2016-03-04 8:23 ` Li, Liang Z
2016-03-04 8:23 ` Li, Liang Z
2016-03-04 8:23 ` Li, Liang Z
2016-03-04 8:35 ` Roman Kagan
2016-03-04 8:35 ` Roman Kagan
2016-03-04 8:35 ` Roman Kagan
2016-03-04 9:08 ` Dr. David Alan Gilbert
2016-03-04 9:08 ` Dr. David Alan Gilbert
2016-03-04 9:08 ` Dr. David Alan Gilbert
2016-03-04 9:08 ` Dr. David Alan Gilbert
2016-03-04 9:12 ` Li, Liang Z
2016-03-04 9:12 ` Li, Liang Z
2016-03-04 9:12 ` Li, Liang Z
2016-03-04 9:12 ` Li, Liang Z
2016-03-04 9:47 ` Michael S. Tsirkin
2016-03-04 9:47 ` Michael S. Tsirkin
2016-03-04 9:47 ` Michael S. Tsirkin
2016-03-04 9:47 ` Michael S. Tsirkin
2016-03-04 10:11 ` Li, Liang Z
2016-03-04 10:11 ` Li, Liang Z
2016-03-04 10:11 ` Li, Liang Z
2016-03-04 10:11 ` Li, Liang Z
2016-03-04 10:36 ` Michael S. Tsirkin
2016-03-04 10:36 ` Michael S. Tsirkin
2016-03-04 10:36 ` Michael S. Tsirkin
2016-03-04 10:36 ` Michael S. Tsirkin
2016-03-04 15:13 ` Li, Liang Z
2016-03-04 15:13 ` Li, Liang Z
2016-03-04 15:13 ` Li, Liang Z
2016-03-04 15:13 ` Li, Liang Z
2016-03-08 14:03 ` Michael S. Tsirkin
2016-03-08 14:03 ` Michael S. Tsirkin
2016-03-08 14:03 ` Michael S. Tsirkin
2016-03-08 14:03 ` Michael S. Tsirkin
2016-03-08 14:17 ` Li, Liang Z
2016-03-08 14:17 ` Li, Liang Z
2016-03-08 14:17 ` Li, Liang Z
2016-03-08 14:17 ` Li, Liang Z
2016-03-08 14:17 ` Li, Liang Z
2016-03-08 14:03 ` Michael S. Tsirkin
2016-03-04 9:35 ` Roman Kagan
2016-03-04 9:35 ` Roman Kagan
2016-03-04 9:35 ` Roman Kagan
2016-03-04 9:35 ` Roman Kagan
2016-03-04 8:35 ` Roman Kagan
2016-03-04 7:55 ` Roman Kagan
2016-03-03 17:46 ` Dr. David Alan Gilbert
2016-03-08 11:13 ` Amit Shah
2016-03-08 11:13 ` [Qemu-devel] " Amit Shah
2016-03-08 11:13 ` Amit Shah
2016-03-08 11:13 ` Amit Shah
2016-03-08 13:11 ` Li, Liang Z
2016-03-08 13:11 ` Li, Liang Z
2016-03-08 13:11 ` [Qemu-devel] " Li, Liang Z
2016-03-08 13:11 ` Li, Liang Z
2016-03-10 7:44 ` Li, Liang Z
2016-03-10 7:44 ` Li, Liang Z
2016-03-10 7:44 ` [Qemu-devel] " Li, Liang Z
2016-03-10 7:44 ` Li, Liang Z
2016-03-10 7:57 ` Amit Shah
2016-03-10 7:57 ` Amit Shah
2016-03-10 7:57 ` [Qemu-devel] " Amit Shah
2016-03-10 7:57 ` Amit Shah
2016-03-10 8:36 ` Li, Liang Z
2016-03-10 8:36 ` [Qemu-devel] " Li, Liang Z
2016-03-10 8:36 ` Li, Liang Z
2016-03-10 11:18 ` Dr. David Alan Gilbert
2016-03-10 11:18 ` Dr. David Alan Gilbert
2016-03-10 11:18 ` [Qemu-devel] " Dr. David Alan Gilbert
2016-03-10 11:18 ` Dr. David Alan Gilbert
2016-03-11 2:38 ` Li, Liang Z
2016-03-11 2:38 ` [Qemu-devel] " Li, Liang Z
2016-03-11 2:38 ` Li, Liang Z
2016-03-14 17:03 ` Dr. David Alan Gilbert
2016-03-14 17:03 ` Dr. David Alan Gilbert
2016-03-14 17:03 ` [Qemu-devel] " Dr. David Alan Gilbert
2016-03-14 17:03 ` Dr. David Alan Gilbert
2016-03-14 17:03 ` Dr. David Alan Gilbert
2016-03-15 3:31 ` Li, Liang Z
2016-03-15 3:31 ` [Qemu-devel] " Li, Liang Z
2016-03-15 3:31 ` Li, Liang Z
2016-03-15 3:31 ` Li, Liang Z
2016-03-15 3:31 ` Li, Liang Z
2016-03-15 10:29 ` Michael S. Tsirkin
2016-03-15 10:29 ` Michael S. Tsirkin
2016-03-15 10:29 ` [Qemu-devel] " Michael S. Tsirkin
2016-03-15 10:29 ` Michael S. Tsirkin
2016-03-15 11:11 ` Li, Liang Z
2016-03-15 11:11 ` [Qemu-devel] " Li, Liang Z
2016-03-15 11:11 ` Li, Liang Z
2016-03-15 11:11 ` Li, Liang Z
2016-03-15 19:55 ` Dr. David Alan Gilbert
2016-03-15 19:55 ` [Qemu-devel] " Dr. David Alan Gilbert
2016-03-15 19:55 ` Dr. David Alan Gilbert
2016-03-15 19:55 ` Dr. David Alan Gilbert
2016-03-16 1:20 ` Li, Liang Z
2016-03-16 1:20 ` [Qemu-devel] " Li, Liang Z
2016-03-16 1:20 ` Li, Liang Z
2016-03-16 1:20 ` Li, Liang Z
2016-03-11 2:38 ` Li, Liang Z
2016-03-10 8:36 ` Li, Liang Z
2016-03-04 9:32 [Qemu-devel] " Jitendra Kolhe
2016-03-04 9:36 ` Li, Liang Z
2016-03-08 11:14 ` Amit Shah
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='20160309132210.GA5869__44243.7048689046$1457529769$gmane$org@rkaganb.sw.ru' \
--to=rkagan@virtuozzo.com \
--cc=akpm@linux-foundation.org \
--cc=amit.shah@redhat.com \
--cc=dgilbert@redhat.com \
--cc=ehabkost@redhat.com \
--cc=kvm@vger.kernel.org \
--cc=liang.z.li@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mst@redhat.com \
--cc=pbonzini@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=rth@twiddle.net \
--cc=virtualization@lists.linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.