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

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.