[CentOS] kernel memory accounting

Wensheng Deng wd35 at nyu.edu
Fri Mar 10 20:51:35 UTC 2017


I have 3.10 kernel. I am running some data processing job, need to first
copy big (>5 GB) input files. The jobs were killed, because the system
thought I used 5 GB memory from the file copying.


On Fri, Mar 10, 2017 at 3:04 PM, David Both <dboth at millennium-technology.com
> wrote:

> First - why in the world would you want to disable kernel memory
> accounting? I don't think that is even possible (despite not being a kernel
> programmer myself) because the kernel must needs account for every bit of
> real and virtual memory in the system in order to do its job.
>
> Second - the first note in the doc to which you refer says that it is
> hopelessly out of date and further down it indicates it refers to 2.6
> kernels and we are now at 4.9.
>
> So now my question boils down to - what is it that you are trying to do
> that makes you think you have to disable kernel memory accounting?
>
>
>
> On 03/10/2017 02:25 PM, Wensheng Deng wrote:
>
>> Hi CentOS experts,
>>
>> I am using CentOS 7. Trying to disable kernel memory accounting:
>> according to https://www.kernel.org/doc/Documentation/cgroup-v1/memory.
>> txt,
>>   passing cgroup.memory=nokmem to the kernel at boot time, should be able
>> to
>> archive that.
>>
>> However it is not the case in my exercise.  These are what I have now
>> $ grep CONFIG_MEMCG_KMEM /boot/config-3.10.0-327.36.3.el7.x86_64
>>
>> CONFIG_MEMCG_KMEM=y
>>
>> $ cat /proc/cmdline
>>
>> BOOT_IMAGE=/vmlinuz-3.10.0-327.36.3.el7.x86_64
>> root=UUID=56568066-5719-46d9-981d-278c7559689b ro quiet
>> cgroup.memory=nokmem
>> systemd.log_level=debug
>>
>> But kernel memory is still accounted in user's applications. Any
>> suggestion
>> on how to chase the issue is greatly appreciated!  Thank you!
>>
>>
>> Best Regards,
>> Wensheng
>> _______________________________________________
>> CentOS mailing list
>> CentOS at centos.org
>> https://lists.centos.org/mailman/listinfo/centos
>>
>
> --
>
>
> *********************************************************
> David P. Both, RHCE
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>
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