Re: [PATCH v4 0/3] perf: add support for analyzing events for containers

From: Aravinda Prasad
Date: Wed Jan 11 2017 - 06:16:20 EST




On Wednesday 04 January 2017 02:34 PM, Krister Johansen wrote:
> On Tue, Jan 03, 2017 at 04:57:54PM +0530, Hari Bathini wrote:
>> On Thursday 29 December 2016 07:11 AM, Krister Johansen wrote:
>>> On Fri, Dec 16, 2016 at 12:06:55AM +0530, Hari Bathini wrote:
>>>> This patch-set overcomes this limitation by using cgroup identifier as
>>>> container unique identifier. A new PERF_RECORD_NAMESPACES event that
>>>> records namespaces related info is introduced, from which the cgroup
>>>> namespace's device & inode numbers are used as cgroup identifier. This
>>>> is based on the assumption that each container is created with it's own
>>>> cgroup namespace allowing assessment/analysis of multiple containers
>>>> using cgroup identifier.
>>> Why choose cgroups when the kernel dispenses namespace-unique
>>> identifiers. Cgroup membership can be arbitrary. Moreover, cgroup and
>>
>> Agreed. But doesn't that hold for any other namespace or a combination
>> of namespaces as well?
>
> I guess that's part of my concern. There is no container-unique
> identifier on the system, since the notion of containers is a construct
> of higer-level software.

I wish we had a container-unique identifier. A container-unique
identifier will make things a lot more better, not just for
container-aware tracing but for audit subsystem as well.

https://lwn.net/Articles/699819/#Comments

--
Regards,
Aravinda