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What is OpenVZ container scheduling granularity [message #44670] Tue, 20 December 2011 20:21 Go to next message
shule ney is currently offline  shule ney
Messages: 17
Registered: March 2011
Junior Member
From: *parallels.com
Hi all:
I'm eager to know what is OpenVZ container scheduling granularity, 1ms or
something??? I really need information about this.
Re: What is OpenVZ container scheduling granularity [message #44673 is a reply to message #44670] Wed, 21 December 2011 07:58 Go to previous messageGo to next message
Kirill Korotaev is currently offline  Kirill Korotaev
Messages: 137
Registered: January 2006
Senior Member
From: *parallels.com
It's floating, depends on priorities. Plus more important for latency is not granularity, but preemptiveness.

Sent from my iPhonespam SPAMSPAM

On 21.12.2011, at 0:34, "shule ney" <neyshule@gmail.com> wrote:

> Hi all:
> I'm eager to know what is OpenVZ container scheduling granularity, 1ms or something??? I really need information about this.
> <ATT00001.c>
Re: What is OpenVZ container scheduling granularity [message #44676 is a reply to message #44673] Wed, 21 December 2011 15:50 Go to previous messageGo to next message
shule ney is currently offline  shule ney
Messages: 17
Registered: March 2011
Junior Member
From: *parallels.com
Much thanks Kirill, I really appreciate your reply! My question is:
Suppose two containers exist on my machine which can use 0%-100% CPU, each
of them has only one active process. If I sleep one container's process for
1us which makes this container has nothing to do, will the the container be
scheduled off and the other container gets scheduled? Is 1us too small for
container scheduling?? I want to know if this case is possible. Thanks very
much.

2011/12/21 Kirill Korotaev <dev@parallels.com>

> It's floating, depends on priorities. Plus more important for latency is
> not granularity, but preemptiveness.
>
> Sent from my iPhonespam SPAMSPAM
>
> On 21.12.2011, at 0:34, "shule ney" <neyshule@gmail.com> wrote:
>
> > Hi all:
> > I'm eager to know what is OpenVZ container scheduling granularity, 1ms
> or something??? I really need information about this.
> > <ATT00001.c>
>
Re: What is OpenVZ container scheduling granularity [message #44677 is a reply to message #44676] Wed, 21 December 2011 16:14 Go to previous messageGo to next message
Kirill Korotaev is currently offline  Kirill Korotaev
Messages: 137
Registered: January 2006
Senior Member
From: *parallels.com
if CPU has nothing to do since your app went to sleep (even for 1us), it will be rescheduled to another CPU. Just like for conventional tasks in Linux.


On Dec 21, 2011, at 19:50 , shule ney wrote:

> Much thanks Kirill, I really appreciate your reply! My question is:
> Suppose two containers exist on my machine which can use 0%-100% CPU, each of them has only one active process. If I sleep one container's process for 1us which makes this container has nothing to do, will the the container be scheduled off and the other container gets scheduled? Is 1us too small for container scheduling?? I want to know if this case is possible. Thanks very much.
>
> 2011/12/21 Kirill Korotaev <dev@parallels.com>
> It's floating, depends on priorities. Plus more important for latency is not granularity, but preemptiveness.
>
> Sent from my iPhonespam SPAMSPAM
>
> On 21.12.2011, at 0:34, "shule ney" <neyshule@gmail.com> wrote:
>
> > Hi all:
> > I'm eager to know what is OpenVZ container scheduling granularity, 1ms or something??? I really need information about this.
> > <ATT00001.c>
>
Re: What is OpenVZ container scheduling granularity [message #44678 is a reply to message #44676] Wed, 21 December 2011 16:24 Go to previous messageGo to next message
MailingListe is currently offline  MailingListe
Messages: 29
Registered: May 2008
Junior Member
From: *parallels.com
Zitat von shule ney <neyshule@gmail.com>:

> Much thanks Kirill, I really appreciate your reply! My question is:
> Suppose two containers exist on my machine which can use 0%-100% CPU, each
> of them has only one active process. If I sleep one container's process for
> 1us which makes this container has nothing to do, will the the container be
> scheduled off and the other container gets scheduled? Is 1us too small for
> container scheduling?? I want to know if this case is possible. Thanks very
> much.

OpenVZ is shared Kernel so you must think of scheduling per
process(-group) like in a conventional Kernel, not per container.

Regards

Andreas
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Re: What is OpenVZ container scheduling granularity [message #44679 is a reply to message #44678] Wed, 21 December 2011 16:49 Go to previous messageGo to next message
shule ney is currently offline  shule ney
Messages: 17
Registered: March 2011
Junior Member
From: *parallels.com
Thanks very much lst_hoe02, if I'm using kernel-2.6.24 which uses CFS
scheduler with nanosecond *granularity, processes *across* different
containers/groups should also have this * *granularity all right? *

2011/12/21 <lst_hoe02@kwsoft.de>

> Zitat von shule ney <neyshule@gmail.com>:
>
>
> Much thanks Kirill, I really appreciate your reply! My question is:
>> Suppose two containers exist on my machine which can use 0%-100% CPU,
>> each
>> of them has only one active process. If I sleep one container's process
>> for
>> 1us which makes this container has nothing to do, will the the container
>> be
>> scheduled off and the other container gets scheduled? Is 1us too small for
>> container scheduling?? I want to know if this case is possible. Thanks
>> very
>> much.
>>
>
> OpenVZ is shared Kernel so you must think of scheduling per
> process(-group) like in a conventional Kernel, not per container.
>
> Regards
>
> Andreas
>
>
>
Re: What is OpenVZ container scheduling granularity [message #44681 is a reply to message #44679] Wed, 21 December 2011 17:04 Go to previous messageGo to next message
dowdle is currently offline  dowdle
Messages: 261
Registered: December 2005
Location: Bozeman, Montana
Senior Member
From: *coe.montana.edu
Greetings,

----- Original Message -----
> Thanks very much lst_hoe02, if I'm using kernel-2.6.24 which uses CFS
> scheduler with nanosecond granularity, processes across different
> containers/groups should also have this granularity all right?

Just to clarify, the OpenVZ project has dropped the 2.6.24 branch. What you have may still be supported by Debian/Ubuntu perhaps?

For info about the various OpenVZ kernel branches, please see:

http://wiki.openvz.org/Download/kernel

Just saying.

TYL,
--
Scott Dowdle
704 Church Street
Belgrade, MT 59714
(406)388-0827 [home]
(406)994-3931 [work]


--
TYL, Scott Dowdle
Belgrade, Montana, USA
Re: What is OpenVZ container scheduling granularity [message #44682 is a reply to message #44681] Wed, 21 December 2011 17:18 Go to previous messageGo to next message
shule ney is currently offline  shule ney
Messages: 17
Registered: March 2011
Junior Member
From: *parallels.com
I'm using the old 2.6.24/2.6.24-ovz009.1. It works well for me.

2011/12/21 Scott Dowdle <dowdle@montanalinux.org>

> Greetings,
>
> ----- Original Message -----
> > Thanks very much lst_hoe02, if I'm using kernel-2.6.24 which uses CFS
> > scheduler with nanosecond granularity, processes across different
> > containers/groups should also have this granularity all right?
>
> Just to clarify, the OpenVZ project has dropped the 2.6.24 branch. What
> you have may still be supported by Debian/Ubuntu perhaps?
>
> For info about the various OpenVZ kernel branches, please see:
>
> http://wiki.openvz.org/Download/kernel
>
> Just saying.
>
> TYL,
> --
> Scott Dowdle
> 704 Church Street
> Belgrade, MT 59714
> (406)388-0827 [home]
> (406)994-3931 [work]
Re: What is OpenVZ container scheduling granularity [message #44687 is a reply to message #44679] Thu, 22 December 2011 08:30 Go to previous messageGo to next message
MailingListe is currently offline  MailingListe
Messages: 29
Registered: May 2008
Junior Member
From: *parallels.com
Zitat von shule ney <neyshule@gmail.com>:

> Thanks very much lst_hoe02, if I'm using kernel-2.6.24 which uses CFS
> scheduler with nanosecond *granularity, processes *across* different
> containers/groups should also have this * *granularity all right? *

To my knowledge OpenVZ does not alter the scheduler, but only
priorities. So yes it should work, but others may have more insight
then me.

Regards

Andreas
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Re: What is OpenVZ container scheduling granularity [message #44694 is a reply to message #44687] Thu, 22 December 2011 14:59 Go to previous message
shule ney is currently offline  shule ney
Messages: 17
Registered: March 2011
Junior Member
From: *parallels.com
Much thanks for your help lst_hoe02[?]

2011/12/22 <lst_hoe02@kwsoft.de>

> Zitat von shule ney <neyshule@gmail.com>:
>
> Thanks very much lst_hoe02, if I'm using kernel-2.6.24 which uses CFS
>> scheduler with nanosecond *granularity, processes *across* different
>> containers/groups should also have this * *granularity all right? *
>>
>
> To my knowledge OpenVZ does not alter the scheduler, but only priorities.
> So yes it should work, but others may have more insight then me.
>
> Regards
>
> Andreas
>
>
>
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