Re: [PATCH 1/2] perf: add container identifier entry in perf sample data

[Hari Bathini <hbathini@linux.vnet.ibm.com>]

On Thursday 25 August 2016 06:31 PM, Peter Zijlstra wrote:
> On Thu, Aug 25, 2016 at 05:27:54PM +0530, Hari Bathini wrote:
>
>> diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
>> index c66a485..fb4f902 100644
>> --- a/include/uapi/linux/perf_event.h
>> +++ b/include/uapi/linux/perf_event.h
>> @@ -139,8 +139,9 @@ enum perf_event_sample_format {
>>   	PERF_SAMPLE_IDENTIFIER			= 1U << 16,
>>   	PERF_SAMPLE_TRANSACTION			= 1U << 17,
>>   	PERF_SAMPLE_REGS_INTR			= 1U << 18,
>> +	PERF_SAMPLE_CID				= 1U << 19,
>>   
>> -	PERF_SAMPLE_MAX = 1U << 19,		/* non-ABI */
>> +	PERF_SAMPLE_MAX = 1U << 20,		/* non-ABI */
>>   };
> This forgets to update the comment that goes with PERF_RECORD_SAMPLE.
> This patch would also need an update to the manpage:
>
>    http://git.kernel.org/cgit/docs/man-pages/man-pages.git/tree/man2/perf_event_open.2
>
>    http://www.man7.org/linux/man-pages/man2/perf_event_open.2.html
>
>> +	if (sample_type & PERF_SAMPLE_CID) {
>> +		int size = sizeof(u64);
>> +
>> +		/*
>> +		 * Container identifier for a given task.
>> +		 * Using cgroup namespace inode number for this.
>> +		 */
>> +		data->cid_entry.cid = current->nsproxy->cgroup_ns->ns.inum;
>> +		data->cid_entry.reserved = 0;
>> +		header->size += size;
>> +	}
>>   }
> Does this compile with CONFIG_CGROUP=n ?
>

My bad. Will update..
Actually, on second thought, how about using inode number of some
other namespace that any container would have (mount, probably?)..

Thanks
Hari