Re: [PATCH v4 1/3] perf: add PERF_RECORD_NAMESPACES to include namespaces related info

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

On Friday 16 December 2016 12:16 AM, Peter Zijlstra wrote:
> On Fri, Dec 16, 2016 at 12:07:06AM +0530, Hari Bathini wrote:
>> +struct perf_ns_link_info {
>> +	__u64	dev;
>> +	__u64	ino;
>> +};
>> +
>> +enum {
>> +	NET_NS_INDEX		= 0,
>> +	UTS_NS_INDEX		= 1,
>> +	IPC_NS_INDEX		= 2,
>> +	PID_NS_INDEX		= 3,
>> +	USER_NS_INDEX		= 4,
>> +	MNT_NS_INDEX		= 5,
>> +	CGROUP_NS_INDEX		= 6,
>> +
>> +	NAMESPACES_MAX,		/* maximum available namespaces */
>> +};
>> +
>>   enum perf_event_type {
>>   
>>   	/*
>> @@ -862,6 +880,17 @@ enum perf_event_type {
>>   	 */
>>   	PERF_RECORD_SWITCH_CPU_WIDE		= 15,
>>   
>> +	/*
>> +	 * struct {
>> +	 *	struct perf_event_header	header;
>> +	 *	u32				pid;
>> +	 *	u32				tid;
>> +	 *	struct namespace_link_info	link_info[NAMESPACES_MAX];
>> +	 *	struct sample_id		sample_id;
>> +	 * };
>> +	 */
>> +	PERF_RECORD_NAMESPACES			= 16,
>> +
>>   	PERF_RECORD_MAX,			/* non-ABI */
>>   };
> What happens if a future kernel adds another namespace?
>

No impact unless NAMESPACES_MAX in include/uapi/linux/perf_event.h is 
updated to accommodate that..
And if it is updated, the corresponding change is expected in perf-tool 
as well..

Thanks
Hari