Re: [PATCH v7 8/8] perf tool: add cgroup identifier entry in perf report

[Jiri Olsa <jolsa@redhat.com>]

On Tue, Feb 21, 2017 at 07:33:13PM +0530, Hari Bathini wrote:
> This patch introduces a cgroup identifier entry field in perf report to
> identify or distinguish data of different cgroups. It uses the device
> number and inode number of cgroup namespace, included in perf data with
> the new PERF_RECORD_NAMESPACES event, as cgroup identifier. With the
> assumption that each container is created with it's own cgroup namespace,
> this allows assessment/analysis of multiple containers at once.
> 
> Shown below is the output of perf report, sorted based on cgroup id, on
> a system that was running three containers at the time of perf record
> and clearly showing one of the containers' considerable use of kernel
> memory in comparison with others:
> 
> 
> 	$ perf report -s cgroup_id,sample --stdio
> 	#
> 	# Total Lost Samples: 0
> 	#
> 	# Samples: 16K of event 'kmem:kmalloc'
> 	# Event count (approx.): 16043
> 	#
> 	# Overhead  cgroup id (dev/inode)       Samples
> 	# ........  .....................  ............
> 	#
> 	    96.33%  3/0xf00000d0                  15454
> 	     3.02%  3/0xeffffffb                    485
> 	     0.31%  3/0xf00000ce                     49
> 	     0.29%  3/0xf00000cf                     47
> 	     0.05%  0/0x0                             8
> 
> While this is a start, there is further scope of improving this. For
> example, instead of cgroup namespace's device and inode numbers, dev
> and inode numbers of some or all namespaces may be used to distinguish
> which processes are running in a given container context. Also, scripts
> to map device and inode info to containers sounds plausible for better
> tracing of containers.
> 
> Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
> ---
>  tools/perf/util/hist.c |    7 +++++++
>  tools/perf/util/hist.h |    1 +
>  tools/perf/util/sort.c |   41 +++++++++++++++++++++++++++++++++++++++++
>  tools/perf/util/sort.h |    7 +++++++
>  4 files changed, 56 insertions(+)

missing documentation update with new sorting field...

other than that the rest looks ok to me, for the patchset:

Acked-by: Jiri Olsa <jolsa@kernel.org>

thanks,
jirka