* cgroup freezer
@ 2012-02-20 9:50 bill4carson
2012-02-20 15:06 ` Mulyadi Santosa
0 siblings, 1 reply; 5+ messages in thread
From: bill4carson @ 2012-02-20 9:50 UTC (permalink / raw)
To: kernelnewbies
From Documentation/cgroups/freezer-subsystem.txt, the following words
describe the purpose of cgroups freezer:
"The cgroup freezer is useful to batch job management system which start
and stop sets of tasks in order to schedule the resources of a machine
according to the desires of a system administrator."
IMHO, when system load is high, administrator could freeze some of
cpu-hogged tasks in favor of more important ones, once system is most
likely to be idle, frozen tasks could be thaw back on line.
I don't know this idea is right or wrong, can somebody give me some
hints about practical usage of cgroup freezer?
thanks
--
I am a slow learner
but I will keep trying to fight for my dreams!
--bill
^ permalink raw reply [flat|nested] 5+ messages in thread
* cgroup freezer
2012-02-20 9:50 cgroup freezer bill4carson
@ 2012-02-20 15:06 ` Mulyadi Santosa
2012-02-21 1:23 ` bill4carson
0 siblings, 1 reply; 5+ messages in thread
From: Mulyadi Santosa @ 2012-02-20 15:06 UTC (permalink / raw)
To: kernelnewbies
Hi Bill :)
On Mon, Feb 20, 2012 at 16:50, bill4carson <bill4carson@gmail.com> wrote:
> IMHO, when system load is high, administrator could freeze some of
> cpu-hogged tasks in favor of more important ones, once system is most
> likely to be idle, frozen tasks could be thaw back on line.
what you describe, IIRC, is something doable via "batch" command
> I don't know this idea is right or wrong, can somebody give me some
> hints about practical usage of cgroup freezer?
IMHO, it's also useful if you manage computer grid. So say you have 16
nodes. A job runs on node A, but later you found that node C has the
least load. You freeze the job and then unfreeze it in C.
Of course, it assumes that the nodes are homogen. And yes, it sounds
very similar to virtual machine migration. basically, both of them
have same principle on how to get things done.
--
regards,
Mulyadi Santosa
Freelance Linux trainer and consultant
blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com
^ permalink raw reply [flat|nested] 5+ messages in thread
* cgroup freezer
2012-02-20 15:06 ` Mulyadi Santosa
@ 2012-02-21 1:23 ` bill4carson
2012-02-21 17:08 ` Mulyadi Santosa
0 siblings, 1 reply; 5+ messages in thread
From: bill4carson @ 2012-02-21 1:23 UTC (permalink / raw)
To: kernelnewbies
On 2012?02?20? 23:06, Mulyadi Santosa wrote:
> Hi Bill :)
>
> On Mon, Feb 20, 2012 at 16:50, bill4carson<bill4carson@gmail.com> wrote:
>> IMHO, when system load is high, administrator could freeze some of
>> cpu-hogged tasks in favor of more important ones, once system is most
>> likely to be idle, frozen tasks could be thaw back on line.
>
> what you describe, IIRC, is something doable via "batch" command
>
>> I don't know this idea is right or wrong, can somebody give me some
>> hints about practical usage of cgroup freezer?
>
> IMHO, it's also useful if you manage computer grid. So say you have 16
> nodes. A job runs on node A, but later you found that node C has the
> least load. You freeze the job and then unfreeze it in C.
>
Thanks for your reply :)
Just one silly question, how could frozen task be moved from node A to
C ?
> Of course, it assumes that the nodes are homogen. And yes, it sounds
> very similar to virtual machine migration. basically, both of them
> have same principle on how to get things done.
>
Yes, KVM+qemu have already support this feature.
--
I am a slow learner
but I will keep trying to fight for my dreams!
--bill
^ permalink raw reply [flat|nested] 5+ messages in thread
* cgroup freezer
2012-02-21 1:23 ` bill4carson
@ 2012-02-21 17:08 ` Mulyadi Santosa
2012-02-22 1:18 ` bill4carson
0 siblings, 1 reply; 5+ messages in thread
From: Mulyadi Santosa @ 2012-02-21 17:08 UTC (permalink / raw)
To: kernelnewbies
Hi Bill :)
On Tue, Feb 21, 2012 at 08:23, bill4carson <bill4carson@gmail.com> wrote:
> Just one silly question, how could frozen task be moved from node A to
> C ?
I forgot to mention that I haven't tried the freezer feature in Linux
kernel, but I got impression that is quite similar with so called
checkpointing.
So assuming that it's indeed checkpointing, what you need to do is
just grab the checkpointed image, copy to another node and execute a
command to unfreeze it. Usually, the image could be similar with ELF
dump core, but it could be something else too.
--
regards,
Mulyadi Santosa
Freelance Linux trainer and consultant
blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com
^ permalink raw reply [flat|nested] 5+ messages in thread
* cgroup freezer
2012-02-21 17:08 ` Mulyadi Santosa
@ 2012-02-22 1:18 ` bill4carson
0 siblings, 0 replies; 5+ messages in thread
From: bill4carson @ 2012-02-22 1:18 UTC (permalink / raw)
To: kernelnewbies
On 2012?02?22? 01:08, Mulyadi Santosa wrote:
> Hi Bill :)
>
> On Tue, Feb 21, 2012 at 08:23, bill4carson<bill4carson@gmail.com> wrote:
>> Just one silly question, how could frozen task be moved from node A to
>> C ?
>
> I forgot to mention that I haven't tried the freezer feature in Linux
> kernel, but I got impression that is quite similar with so called
> checkpointing.
>
> So assuming that it's indeed checkpointing, what you need to do is
> just grab the checkpointed image, copy to another node and execute a
> command to unfreeze it. Usually, the image could be similar with ELF
> dump core, but it could be something else too.
>
Thanks for your information, I'll make some time to try what checkpoint
does.
--
I am a slow learner
but I will keep trying to fight for my dreams!
--bill
^ permalink raw reply [flat|nested] 5+ messages in thread
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2012-02-20 9:50 cgroup freezer bill4carson
2012-02-20 15:06 ` Mulyadi Santosa
2012-02-21 1:23 ` bill4carson
2012-02-21 17:08 ` Mulyadi Santosa
2012-02-22 1:18 ` bill4carson
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