Re: [RFC 01/16] blkcg:Introduce blkio.app_identifier knob to blkio controller

James Smart
2020-08-05T00:40:05Z

On 8/4/2020 7:21 AM, Tejun Heo wrote:
> Hello,
>
> On Tue, Aug 04, 2020 at 01:31:30PM +0200, Daniel Wagner wrote:
>> Hi,
>>
>> [cc Tejun]
>>
>> On Tue, Aug 04, 2020 at 07:43:01AM +0530, Muneendra wrote:
>>> This Patch added a unique application identifier i.e
>>> blkio.app_identifier knob to blkio controller which
>>> allows identification of traffic sources at an
>>> individual cgroup based Applications
>>> (ex:virtual machine (VM))level in both host and
>>> fabric infrastructure.
> I'm not sure it makes sense to introduce custom IDs for these given that
> there already are unique per-host cgroup IDs which aren't recycled.
>
> Thanks.
>

If the VM moves to a different host, does the per-host cgroup IDs
migrate with the VM ?   If not, we need to have an identifier that moves
with the VM and which is independent of what host the VM is residing on.

-- james