[CRIU] [PATCH v2 11/57] pid: Add equel_pid() helper

[Kirill Tkhai]

On 07.04.2017 03:33, Andrei Vagin wrote:
> On Tue, Mar 28, 2017 at 06:35:47PM +0300, Kirill Tkhai wrote:
>> This allows to compare pids values on the whole hierarhy.
>>
>> Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
>> ---
>>  criu/include/pid.h |   17 +++++++++++++++++
>>  1 file changed, 17 insertions(+)
>>
>> diff --git a/criu/include/pid.h b/criu/include/pid.h
>> index 475b17a3..478e5d0b 100644
>> --- a/criu/include/pid.h
>> +++ b/criu/include/pid.h
>> @@ -4,6 +4,7 @@
>>  #include <compel/task-state.h>
>>  #include "stdbool.h"
>>  #include "rbtree.h"
>> +#include "log.h"
>>  
>>  /*
>>   * Task states, used in e.g. struct pid's state.
>> @@ -45,6 +46,22 @@ struct pid {
>>  	} ns[1]; /* Must be at the end of struct pid */
>>  };
>>  
>> +#define equal_pid(a, b)							\
>> +({									\
>> +	int ___i, ___ret = true;					\
>> +	if (a->level == b->level) {					\
>> +		for (___i = 0; ___i < a->level; ___i++)			\
>> +			if (a->ns[___i].virt != b->ns[___i].virt) {	\
>> +				___ret = false;				\
>> +				break;					\
>> +			}						\
>> +	} else {							\
>> +		pr_err("Wrong pid nesting level\n");			\
> 
> Why do we need this message here?

It's a debug message to report that we compare variables of different dimensions
 
>> +		___ret = false;						\
>> +	}								\
>> +	___ret;								\
>> +})
>> +
>>  /*
>>   * When we have to restore a shared resource, we mush select which
>>   * task should do it, and make other(s) wait for it. In order to
>>