Re: [PATCH 3/3] tracing/mm: Don't trace mm_page_pcpu_drain on offline cpus

[Shreyas B Prabhu <shreyas@linux.vnet.ibm.com>]

>> -DEFINE_EVENT_PRINT(mm_page, mm_page_pcpu_drain,
>> +TRACE_EVENT_CONDITION(mm_page_pcpu_drain,
>>
>>         TP_PROTO(struct page *page, unsigned int order, int migratetype),
>>
>>         TP_ARGS(page, order, migratetype),
>>
>> +       TP_CONDITION(cpu_online(smp_processor_id())),
>> +
>> +       TP_STRUCT__entry(
>> +               __field(        unsigned long,  pfn             )
>> +               __field(        unsigned int,   order           )
>> +               __field(        int,            migratetype     )
>> +       ),
>> +
>> +       TP_fast_assign(
>> +               __entry->pfn            = page ? page_to_pfn(page) : -1UL;
>> +               __entry->order          = order;
>> +               __entry->migratetype    = migratetype;
>> +       ),
>> +
> 
> What was the need to do the above changes besides adding TP_CONDITION ?
> 

IIUC there is no existing macro which can both add a condition and
override printk format, hence the fall back to TRACE_EVENT_CONDITION.

Thanks,
Shreyas